Educational & Research Use Only. Not medical advice. Compounds are research-grade and not FDA-approved unless explicitly noted.
09
Section 09 · 7 compounds

Longevity & Cellular Aging

Mitochondrial, telomere and senescence research, almost entirely preclinical.

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Aging involves many processes at once: declining energy production in mitochondria, accumulating damaged cells, shortening telomeres and changes in gene regulation. The compounds here are studied against those processes. Almost all of the evidence is from cells and animals, and none has been shown to extend human lifespan.

Each entry opens with an evidence grade, then covers how the compound works, what human, animal and cell studies show, safety, open questions and regulatory status, with numbered references. Grades in this section: B: 1 · C: 2 · D: 4.

C
Evidence grade C · Limited humanWhat this means

Directly infused or injected NAD+ has only one 11-person pilot study in humans[1]; randomized trials exist for oral precursors such as NR and NMN, but those test a different route and molecule and show modest, mixed results[2,3,4].

A coenzyme, not a peptide, that every cell uses to turn food into energy; its levels fall with age, but human evidence for topping it up, especially by IV, is thin.

Overview

NAD+ (nicotinamide adenine dinucleotide) is a small coenzyme, not a peptide, present in every living cell. It shuttles electrons in energy production and is consumed by enzymes involved in DNA repair and cell signaling, which is why research interest grew after mouse studies tied falling NAD+ to aging[5]. People try to raise it two ways: infusing or injecting NAD+ itself, or swallowing precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) that cells convert into NAD+.

Those two routes have very different evidence. Most randomized human trials test oral precursors, which reliably raise NAD+ markers in blood but have produced small or null effects on health outcomes[2,3,4]. For IV NAD+, the main published human study is an 11-person pilot showing the body clears infused NAD+ from blood rapidly[1]. Results from precursor trials should not be assumed to apply to IV or injected NAD+.

A rechargeable shuttle busNAD+ works like a shuttle bus that picks up electrons from food and drops them off at the cell's power plant, then returns empty to do it again. Some enzymes also scrap buses for parts to fuel repair work. Precursor supplements send the cell bus-building kits; IV NAD+ tries to deliver finished buses from outside, but many get dismantled in the bloodstream before they reach the depot.

Mechanism of Action

Inside cells, NAD+ and its reduced form NADH carry electrons from the breakdown of glucose and fat to the mitochondria, where that energy is captured as ATP. NAD+ is also used up as a raw material by sirtuins, PARP DNA-repair enzymes and the enzyme CD38, so its level reflects a balance between how fast it is made and how fast it is consumed[1,5]. Cells rebuild most of their NAD+ through a salvage pathway that recycles nicotinamide via NMN. In mice, giving NMN for 12 months raised tissue NAD+ and blunted several age-related declines, which drove much of the human interest[5].

How NAD+ gets into cells depends on the route. Oral NR and NMN are absorbed and converted through known pathways; NR raised blood-cell NAD+ by about 60% in one trial[2]. Intact NAD+ is a large, charged molecule that does not easily cross cell membranes. In the IV pilot, plasma NAD+ did not rise at all for the first 2 hours of a slow infusion, and the breakdown products pointed to enzymes such as CD38 and pyrophosphatases rapidly dismantling it in the blood[1]. Whether infused NAD+ meaningfully raises NAD+ inside tissues has not been measured in humans.

What the Research Shows

Human studies
  • IV NAD+ pilot study, Front Aging Neurosci 2019 (n=11 healthy men, 8 NAD+ vs 3 saline, single 6-hour infusion): plasma NAD+ showed no change for 2 hours, then rose about 398% by the end of the infusion; much was lost in urine. No adverse events occurred at the slow rate tested. Several authors had ties to a company and clinic offering IV NAD+[1].
  • Oral NR crossover RCT, Nat Commun 2018 (n=24 healthy adults aged 55 to 79, 6 weeks each arm): blood-cell NAD+ rose about 60% vs placebo. Blood pressure and arterial stiffness trends were not significant after correction for multiple comparisons[2].
  • Oral NR RCT in obese men, Am J Clin Nutr 2018 (n=40 insulin-resistant men, 12 weeks): NR was safe and raised NAD+ metabolites, but did not improve insulin sensitivity, liver glucose output or fat breakdown[3].
  • Oral NMN RCT, Science 2021 (n=25 postmenopausal women with prediabetes, 10 weeks): muscle insulin sensitivity and insulin signaling improved vs placebo, but blood glucose, blood pressure, lipids, liver fat and inflammatory markers did not change[4].
Animal studies
  • Mice, 12 months of oral NMN: long-term NMN raised tissue NAD+, limited age-related weight gain, improved energy metabolism, insulin sensitivity and eye function, and showed no obvious toxicity[5].
What This Could Mean in Practice

For oral precursors, randomized trials show NR and NMN can raise NAD+ markers and are generally well tolerated over weeks to months, with small, inconsistent effects on metabolic measures[2,3,4]. For IV or injected NAD+, the human evidence is one small pilot showing rapid clearance from blood[1]. Neither route has been shown to slow aging, extend lifespan or improve energy in healthy people, and the large mouse effects have not translated cleanly to humans[5].

Safety & Side Effects
  • Oral NR: in a 12-week crossover, adverse events were mild (nausea, flushing, leg cramps, bruising), and blood chemistry was unchanged[2]. A 12-week trial in obese men also found NR safe[3].
  • IV NAD+: no adverse events were seen in 8 people at one slow infusion rate; minor, clinically insignificant liver-test shifts occurred[1]. Faster rates and repeated infusions have not been studied in published trials.
  • Unregulated infusion settings: a July 2026 death in New York one hour after an IV NAD+ infusion was publicized by a drug-safety group; the cause had not been established and the person administering it was reported to be unlicensed[8].
  • FDA has not evaluated NAD+ for injection for safety, efficacy or quality; it remains under evaluation for compounding[6].

Open Questions

  • Whether IV or injected NAD+ raises NAD+ inside muscle, brain or other tissues in humans has not been measured[1].
  • Whether raising NAD+ changes hard outcomes such as disease rates, function or lifespan in people is untested; current trials use short durations and surrogate markers[2,3,4].
  • Long-term effects of chronically elevated NAD+ metabolites, including on cancer growth, are not known.
  • Most human IV data come from investigators with commercial ties to IV NAD+ clinics[1].

Regulatory Status

NAD+ is not an FDA-approved drug; as of May 2026 it sits in FDA's 503A Category 1 (bulk substances under evaluation), which allows pharmacy compounding while review continues[6]. In September 2025 FDA reversed its earlier position and said the oral precursor NMN may be sold as a dietary supplement[7].

Related Compounds

5-Amino-1MQSS-31MOTS-C
References (8)
  1. Grant R, Berg J, Mestayer R, et al. A pilot study investigating changes in the human plasma and urine NAD+ metabolome during a 6 hour intravenous infusion of NAD+. Front Aging Neurosci. 2019;11:257. DOI: 10.3389/fnagi.2019.00257
  2. Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9(1):1286. PMID: 29599478
  3. Dollerup OL, Christensen B, Svart M, et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. Am J Clin Nutr. 2018;108(2):343-353. PMID: 29992272
  4. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. PMID: 33888596
  5. Mills KF, Yoshida S, Stein LR, et al. Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice. Cell Metab. 2016;24(6):795-806. PMID: 28068222
  6. U.S. Food and Drug Administration. Bulk drug substances nominated for use in compounding under section 503A of the FD&C Act (categories list, updated May 14, 2026). 2026. fda.gov
  7. Venable LLP. FDA declares nicotinamide mononucleotide is a dietary supplement (summary of FDA citizen petition response letters dated September 29, 2025). 2025. venable.com
  8. Partnership for Safe Medicines. Death of woman in New York from compounded drug shows the risk of allowing compounding of untested substances. Press release. July 22, 2026. safemedicines.org

Sources last reviewed October 2026.

D
Evidence grade D · Animal onlyWhat this means

Humanin and its analog HNG have been given only to cells and animals; human data are limited to observational measurements of natural blood levels and genetics[2,4,5].

A tiny protective peptide encoded in mitochondrial DNA. It shields cells and animal tissues from stress in lab studies, but it has never been tested as a treatment in people.

Overview

Humanin was discovered in 2001 when Japanese researchers screening for genes that protect neurons found a short peptide that stopped neurons dying from Alzheimer's-linked gene mutations and amyloid-beta[1]. It is encoded inside the mitochondrial genome, in the 16S rRNA region, which made it the first known "mitochondria-derived peptide"[2].

Since then, mostly from a small number of U.S. labs, humanin and a more potent lab-made analog called HNG have shown protective effects in rodent models of heart attack, diabetes and brain aging[3,4,6]. In people, blood levels fall with age and are higher in children of centenarians[2,5], but no clinical trial of humanin has been published[2].

A smoke detector that also calls the fire crewMitochondria sense when a cell is under stress. Humanin is one of the messages they send out, both inside the cell to block the self-destruct switch and outside it to tell neighboring cells to brace. In animals, adding extra humanin is like installing more of these alarms, but whether that helps people is unknown.

Mechanism of Action

Humanin is about 24 amino acids long and acts through two routes[2]. Outside the cell, it binds a three-part receptor made of gp130, WSX1 and the CNTF receptor, and a second receptor, formyl peptide receptor 2. These activate the AKT, ERK1/2 and STAT3 survival pathways[2]. Inside the cell, two labs independently found that it binds the cell-death proteins BAX and IGFBP3, blocking them from triggering apoptosis[2]. In rodents, humanin delivered into the brain improved whole-body insulin sensitivity through hypothalamic STAT3, and blocking STAT3 erased the effect[3].

Most animal work uses HNG, a version with glycine replacing serine at position 14 that is far more potent[4]. Natural humanin's half-life is about 20 minutes[2]. A key measurement problem is that the nuclear genome carries humanin-like copies (NUMTs), so it is not always clear which peptide blood tests are detecting[2]. That uncertainty complicates every human association study.

What the Research Shows

Human studies
  • No interventional trials: a 2022 review by the field's leading group describes no human trial of humanin or its analogs[2].
  • Observational genetics, 2018 (BVAIT cohort, about 150 adults; Health and Retirement Study, 10,158 adults): a mitochondrial variant in the humanin gene was linked to 14% lower circulating humanin and an older "cognitive age," about 2 years older in African American carriers. The authors call the findings correlative[4].
  • Observational, 2020 (18 offspring of centenarians vs 19 controls): circulating humanin was significantly higher in centenarians' children (P<0.05)[5].
  • Observational, 2009: circulating humanin declined with age in humans and mice[3].
Animal studies
  • Mice, aging and cognition: female mice given HNG twice weekly from 18 months for up to 14 months showed better Y-maze and Barnes maze performance at 28 months (groups of 7 to 10) and fewer activated microglia, but no change in neurogenesis[4].
  • Mice, healthspan: the same treatment reduced visceral fat and raised lean mass (n=5 per group) and lowered IGF-1, but did not significantly extend lifespan[5].
  • Mice, heart attack: HNG given before or at reperfusion reduced infarct size and improved ejection fraction at 1 week, with AMPK and eNOS activation[6].
  • Pigs, heart attack: HNG reduced infarct size after 60 minutes of ischemia, but not after longer ischemia[7].
  • Rats and worms: an HNG analog lowered blood glucose in diabetic rats after a single treatment[3]; humanin overexpression extended mean worm lifespan from 17.7 to 19.0 days (P<0.05)[5].
Cell & mechanistic
  • Neuronal cells: humanin abolished cell death caused by several familial Alzheimer's disease genes and by amyloid-beta, but not death from other insults such as SOD1 mutants[1].
What This Could Mean in Practice

Right now humanin is a research tool and a biomarker candidate, not a treatment. Animal studies suggest protective effects on the heart, metabolism and brain aging[4,6], but the strongest mouse study found no lifespan extension[5], and the human findings link natural blood levels to health without showing that adding humanin changes anything[2,4]. Any benefit in people, and the safety of injecting it, are unknown.

Safety & Side Effects
  • No human safety data exist for humanin or HNG[2].
  • Long-term HNG in mice lowered body weight and IGF-1[5]; the consequences of those shifts in people are unknown.
  • Transgenic mice with higher humanin had 46.5% smaller litters and shorter bodies, a reminder that the peptide acts on growth and reproduction pathways[5].
  • Products sold outside research settings are unregulated, with unverified identity, purity and sterility.

Open Questions

  • Whether humanin does anything when given to humans has never been tested in a trial[2].
  • Blood tests may confuse mitochondrial humanin with nuclear look-alike peptides, clouding the human association data[2].
  • Most research comes from a small, interconnected group of labs, and independent replication is limited[2,5].
  • In pigs, benefits disappeared with longer heart ischemia, so animal heart results may not scale up[7].

Regulatory Status

Not approved by the FDA or EMA for any use, and no human trials have been reported[2]. It is not named on the WADA list, but non-approved substances fall under WADA's S0 category, prohibited at all times[8].

Related Compounds

MOTS-CSS-31FOXO4-DRI
References (8)
  1. Hashimoto Y, Niikura T, Tajima H, et al. A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta. Proc Natl Acad Sci U S A. 2001;98(11):6336-41. PMID: 11371646
  2. Miller B, Kim SJ, Kumagai H, et al. Mitochondria-derived peptides in aging and healthspan. J Clin Invest. 2022;132(9):e158449. PMID: 35499074
  3. Muzumdar RH, Huffman DM, Atzmon G, et al. Humanin: a novel central regulator of peripheral insulin action. PLoS One. 2009;4(7):e6334. PMID: 19623253
  4. Yen K, Wan J, Mehta HH, et al. Humanin prevents age-related cognitive decline in mice and is associated with improved cognitive age in humans. Sci Rep. 2018;8:14212. DOI: 10.1038/s41598-018-32616-7
  5. Yen K, Mehta HH, Kim SJ, et al. The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan. Aging (Albany NY). 2020;12(12):11185-99. DOI: 10.18632/aging.103534
  6. Muzumdar RH, Huffman DM, Calvert JW, et al. Acute humanin therapy attenuates myocardial ischemia and reperfusion injury in mice. Arterioscler Thromb Vasc Biol. 2010;30(10):1940-8. PMID: 20651283
  7. Sharp TE, et al. Efficacy of a novel mitochondrial-derived peptide in a porcine model of myocardial ischemia/reperfusion injury. JACC Basic Transl Sci. 2020;5:699-714. PMID: 32760857
  8. World Anti-Doping Agency. 2026 Prohibited List, S0 Non-approved substances. wada-ama.org

Sources last reviewed October 2026.

C
Evidence grade C · Limited humanWhat this means

A handful of small human studies, mostly of the parent extract Epithalamin rather than synthetic Epitalon, nearly all from one research network[5,6,7].

A four-amino-acid peptide modeled on a pineal gland extract. Lab studies link it to telomerase activation and modest animal lifespan effects, but the human evidence is thin and comes almost entirely from one group.

Overview

Epitalon is a tiny synthetic peptide (Ala-Glu-Asp-Gly) created by Vladimir Khavinson's group at the St. Petersburg Institute of Bioregulation and Gerontology. It was designed from the amino acid makeup of Epithalamin, a peptide extract taken from animal pineal glands, the small gland that governs melatonin and the body's day-night rhythm[4].

Over roughly 25 years, that group and its collaborators reported that Epitalon switched on telomerase in human cells, restored evening melatonin in old monkeys, and modestly extended lifespan in some strains of mice. In 2025, a UK laboratory independently confirmed telomere lengthening in cell lines[3]. Even so, almost every animal and human finding still comes from one research network, and modern controlled human trials of Epitalon do not exist.

The dimmer switch on old wiringThink of the genes in an aging cell as lights on dimmer switches that have slowly been turned down. Researchers propose that Epitalon reaches the switch box (the chromatin) and nudges a few dimmers back up, including the one for telomerase, the enzyme that rebuilds the protective caps on the ends of chromosomes. The catch: one electrician has done most of the checking, so we don't yet know how reliable that wiring diagram is.

Mechanism of Action

The best-documented effect is telomerase induction. In telomerase-negative human fetal lung fibroblasts, Epitalon induced expression of hTERT (the enzyme's catalytic subunit), measurable telomerase activity, and telomere elongation[1]. Aging fibroblasts that had stopped dividing went on to complete about 10 extra divisions beyond controls[2]. An independent 2025 study confirmed the pattern: in normal fibroblasts and epithelial cells, Epitalon raised hTERT and telomerase activity. In breast cancer cell lines, however, telomeres lengthened mainly through ALT, a telomerase-independent route that cancers use to become immortal[3].

No cell-surface receptor has been identified. The Khavinson group proposes a "peptide bioregulator" model in which very short peptides enter the nucleus and act directly on chromatin. Molecular modeling suggested Epitalon binds histone H1 at DNA-interacting sites, coinciding with 1.6 to 1.8 times higher expression of several neuronal genes in stem cells[10]. The independent 2025 authors describe these chromatin mechanisms as speculative[3]. At the whole-body level, the main proposed effect is restoring the pineal gland's nightly melatonin output in older animals and people[4,5].

What the Research Shows

Human studies
  • Epithalamin (extract) in elderly coronary patients, 12-year follow-up: deaths reported 28% lower than controls on the same baseline therapy, with cardiovascular mortality 2-fold lower. The abstract gives no sample size[6].
  • Epithalamin, elderly coronary patients (n=39 treated vs 40 controls), six courses over 3 years: mortality reported as "significantly lower," with no percentages or statistics in the abstract[7].
  • Epithalamin in healthy elderly people: night-time melatonin rose in those with low pineal function and tended to fall in those with normal function[5].
  • Ex vivo lymphocytes from 11 men exposed to Epitalon: telomeres lengthened in 5, shortened in 2, and did not change significantly in 4[11].
Animal studies
  • Female SHR mice (54 per group), treated from 3 months of age until natural death: no change in average lifespan. Lifespan of the longest-lived 10% rose 13.3%, chromosome aberrations fell 17.1%, and leukemia was 6-fold less common, though overall tumor incidence was unchanged[8].
  • Breast-cancer-prone HER-2/neu transgenic mice: average lifespan up about 13.5%, lung metastases down 1.6-fold[9].
  • Rhesus monkeys (3 per group), 10 days: evening melatonin in old treated monkeys was 48 vs 15 pg/mL in old controls (P<0.001). Young monkeys showed no significant change[4].
Cell & mechanistic
  • Human fetal fibroblasts: induced hTERT, telomerase activity and telomere elongation[1], with about 10 extra population doublings[2].
  • Independent UK replication (2025): dose-dependent telomere lengthening; through telomerase in normal cells, mainly through ALT in breast cancer lines[3].
What This Could Mean in Practice

With a grade C evidence base, real-world relevance is speculative. The cell work suggests Epitalon can influence telomere maintenance in a dish, and that finding has now been partly replicated outside Russia[3]. Animal lifespan gains were modest and strain-dependent[8,9]. The human mortality reports involve a related extract, come from small studies with incomplete reporting, and have not been independently confirmed[6,7]. The finding that cancer cells lengthened their telomeres through ALT is a reason for caution rather than reassurance[3].

Safety & Side Effects
  • No regulatory-grade human safety data exist. The FDA states it lacks enough information to know whether epitalon would cause harm, and flags a potential immunogenicity risk from aggregation and impurities in compounded material[13].
  • A 2025 review notes that critical safety information is missing and calls for studies of genotoxicity, cancer potential and drug interactions[12].
  • In long-term mouse studies, Epitalon did not change food intake or body weight and appeared well tolerated[8].
  • Theoretical concern: in breast cancer cell lines, telomere lengthening occurred through ALT, the pathway some cancers use to escape normal limits on cell division[3].

Open Questions

  • Nearly all animal and human data come from one research network, often published in the same journals. Outside replication is limited to cell studies[3].
  • The human mortality claims concern Epithalamin, not synthetic Epitalon, and the published abstracts omit sample sizes, blinding and effect statistics[6,7].
  • Effects are small or mixed: 3 monkeys per group[4], no change in average mouse lifespan[8], lymphocyte telomeres moving in both directions[11].
  • Whether telomere-lengthening effects could help existing or undiagnosed cancers is unresolved[3].

Regulatory Status

Not FDA-approved for any use. The FDA lists epitalon among substances nominated for compounding that were later withdrawn and removed from Category 2, while noting it lacks sufficient information to judge human safety[13]. Its developers describe the parent extract Epithalamin as a registered pharmaceutical in Russia[4].

Related Compounds

PinealonHumaninNAD+
References (13)
  1. Khavinson VKh, Bondarev IE, Butyugov AA. Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells. Bull Exp Biol Med. 2003;135(6):590-2. PMID: 12937682
  2. Khavinson VKh, Bondarev IE, Butyugov AA, et al. Peptide promotes overcoming of the division limit in human somatic cell. Bull Exp Biol Med. 2004;137(5):503-6. PMID: 15455129
  3. Al-Dulaimi S, Thomas R, Matta S, et al. Epitalon increases telomere length in human cell lines through telomerase upregulation or ALT activity. Biogerontology. 2025;26(5):178. PMID: 40908429
  4. Khavinson V, Goncharova N, Lapin B. Synthetic tetrapeptide epitalon restores disturbed neuroendocrine regulation in senescent monkeys. Neuro Endocrinol Lett. 2001;22:251-254. nel.edu
  5. Korkushko OV, Khavinson VKh, Shatilo VB, et al. Effect of peptide preparation epithalamin on circadian rhythm of epiphyseal melatonin-producing function in elderly people. Bull Exp Biol Med. 2004;137(4):389-91. PMID: 15452611
  6. Korkushko OV, Khavinson VKh, Shatilo VB, et al. Geroprotective effect of epithalamine (pineal gland peptide preparation) in elderly subjects with accelerated aging. Bull Exp Biol Med. 2006;142(3):356-9. PMID: 17426848
  7. Korkushko OV, Khavinson VKh, Shatilo VB, et al. Peptide geroprotector from the pituitary gland inhibits rapid aging of elderly people: results of 15-year follow-up. Bull Exp Biol Med. 2011;151(3):366-9. PMID: 22451889
  8. Anisimov VN, Khavinson VKh, Popovich IG, et al. Effect of Epitalon on biomarkers of aging, life span and spontaneous tumor incidence in female Swiss-derived SHR mice. Biogerontology. 2003;4(4):193-202. PMID: 14501183
  9. Anisimov VN, Khavinson VKh, Alimova IN, et al. Epithalon decelerates aging and suppresses development of breast adenocarcinomas in transgenic her-2/neu mice. Bull Exp Biol Med. 2002;134(2):187-90. PMID: 12459848
  10. Khavinson V, Diomede F, Mironova E, et al. AEDG peptide (Epitalon) stimulates gene expression and protein synthesis during neurogenesis: possible epigenetic mechanism. Molecules. 2020;25(3):609. PMID: 32019204
  11. Khavinson VKh, Pendina AA, Efimova OA, et al. Effect of peptide AEDG on telomere length and mitotic index of PHA-stimulated human blood lymphocytes. Bull Exp Biol Med. 2019;168(1):141-144. PMID: 31761987
  12. Araj SK, Brzezik J, Mądra-Gackowska K, et al. Overview of Epitalon: highly bioactive pineal tetrapeptide with promising properties. Int J Mol Sci. 2025;26(6):2691. PMID: 40141333
  13. U.S. Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks (updated April 22, 2026). fda.gov

Sources last reviewed October 2026.

D
Evidence grade D · Animal onlyWhat this means

All published evidence comes from mice and cultured cells, led by the 2017 Cell study; no human trial has been published[1,2,3].

A lab-designed peptide that pushes senescent "zombie" cells to self-destruct. It restored fitness, fur and kidney function in old mice, but has never been tested in humans.

Overview

FOXO4-DRI is a synthetic peptide designed by Peter de Keizer's group and reported in Cell in 2017[1]. It targets senescent cells, damaged cells that stop dividing but resist dying and leak inflammatory signals into surrounding tissue. The team found that senescent cells lean on a protein called FOXO4 to stay alive, and built a peptide decoy that breaks FOXO4's grip on the tumor suppressor p53[1].

In mice, the peptide countered chemotherapy damage to the liver and improved fur, running activity and kidney markers in both fast-aging and naturally old animals[1]. Other groups have since reported effects in aged mouse testes, irradiated lungs and human cartilage and scar cells in the lab[2,3,4,6]. No human study has been published.

Cutting the lifelineA senescent cell is like a climber dangling over a cliff, held up by a rope (FOXO4) tied to its own self-destruct switch (p53). FOXO4-DRI is a decoy that unties the rope. Freed p53 leaves the nucleus and triggers the cell's built-in demolition program, while healthy cells, which are not hanging by that rope, are largely left alone.

Mechanism of Action

In senescent cells, FOXO4 binds p53 inside the nucleus, which appears to keep p53 from triggering apoptosis (programmed cell death)[1]. FOXO4-DRI mimics the part of FOXO4 that grips p53, competing it away. Released p53 is excluded from the nucleus and acts at mitochondria to start apoptosis[1,2]. In lab tests on human fibroblasts, the peptide was about 11.7 times more toxic to senescent cells than to normal ones, compared with 0.21 for the senolytic drug ABT-737 in repeated low-concentration rounds[1].

"DRI" stands for D-retro-inverso: the peptide is built from mirror-image D-amino acids in reverse order, which preserves its shape while making it resistant to protein-digesting enzymes[1]. It is fused to a cell-penetrating sequence borrowed from HIV-TAT so it can enter cells[1]. The normal L-amino acid version and an unrelated DRI peptide had no effect on senescent cells, supporting the specificity of the design[1]. Human absorption, distribution and half-life have never been measured.

What the Research Shows

Human studies
  • None published. No clinical trial of FOXO4-DRI in humans has been reported. The only human-derived data are from cells and tissue samples studied in the lab[2,3,6].
Animal studies
  • Mice, chemotherapy toxicity (Cell 2017): after doxorubicin, FOXO4-DRI reversed weight loss, lowered liver IL-6 and countered the rise in the liver enzyme AST[1].
  • Fast-aging XpdTTD mice: improved fur, increased wheel running in most animals, and normalized plasma urea and kidney inflammation markers (n=7 to 8 per group for kidney work)[1].
  • Naturally aged mice (104+ weeks), 30 days: lower plasma urea and creatinine and reduced senescence signals; running results were too variable to interpret[1].
  • Aged mice, testes (2020, 2024): in 20 to 24 month old mice, FOXO4-DRI partly restored serum testosterone (n=6 per group)[2], and a later study reported improved sperm quality[5].
  • Mice, radiation lung injury: clearing senescence-like fibroblasts made lung tumors more sensitive to radiation and reduced radiation-induced lung fibrosis[4].
Cell & mechanistic
  • Human chondrocytes: removed more than half of cells in heavily expanded cultures and lowered senescence, but did not improve cartilage formation[3].
  • Human keloid fibroblasts: promoted apoptosis of senescent scar cells in culture and organ culture[6].
What This Could Mean in Practice

FOXO4-DRI is one of the most cited proof-of-concept senolytics, but every result so far comes from mice and cultured cells[1,2]. The mouse benefits were measured over weeks, often in fast-aging strains, and lifespan was not among the reported outcomes[1]. Whether it clears senescent cells in people, at what risk, and with what effect on health is entirely unknown.

Safety & Side Effects
  • No human safety data exist[1].
  • In mice, blood counts including platelets were not noticeably affected, unlike some small-molecule senolytics, and body and kidney weights were stable over the treatment period[1].
  • The peptide increased cell death in ex vivo kidney slices[1]; off-target effects on normal tissue in humans have not been studied.
  • It works by redirecting p53, a central cancer-control protein; long-term consequences of manipulating that pathway are unknown[1].
  • Products sold outside research settings are unregulated, with unverified sequence, purity and sterility.

Open Questions

  • Human pharmacokinetics, safe exposure and efficacy have never been studied.
  • Mouse group sizes were small and many benefits were shown in a genetically fast-aging strain[1].
  • Clearing senescent cells could impair processes that depend on them, such as wound healing; this was not tested.
  • Most follow-up studies come from a few labs, so independent replication of the headline mouse results matters[1,2].

Regulatory Status

Not approved by the FDA or EMA for any use, and no human trial has been published[1]. It is not named on the WADA list, but non-approved substances fall under WADA's S0 category, prohibited at all times[7].

Related Compounds

HumaninEpitalonNAD+
References (7)
  1. Baar MP, Brandt RMC, Putavet DA, et al. Targeted apoptosis of senescent cells restores tissue homeostasis in response to chemotoxicity and aging. Cell. 2017;169(1):132-147.e16. PMID: 28340339
  2. Zhang C, Xie Y, Chen H, et al. FOXO4-DRI alleviates age-related testosterone secretion insufficiency by targeting senescent Leydig cells in aged mice. Aging (Albany NY). 2020;12(2):1272-84. PMID: 31959736
  3. Huang Y, He Y, Makarcyzk MJ, et al. Senolytic peptide FOXO4-DRI selectively removes senescent cells from in vitro expanded human chondrocytes. Front Bioeng Biotechnol. 2021;9:677576. DOI: 10.3389/fbioe.2021.677576
  4. Meng J, Li Y, Wan C, et al. Targeting senescence-like fibroblasts radiosensitizes non-small cell lung cancer and reduces radiation-induced pulmonary fibrosis. JCI Insight. 2021;6(23):e146334. PMID: 34877934
  5. Li Y, et al. FOXO4-DRI improves spermatogenesis in aged mice through reducing senescence-associated secretory phenotype secretion from Leydig cells. Exp Gerontol. 2024;195:112522. PMID: 39025385
  6. Kong YX, Li ZS, Liu YB, et al. FOXO4-DRI induces keloid senescent fibroblast apoptosis by promoting nuclear exclusion of upregulated p53-serine 15 phosphorylation. Commun Biol. 2025;8(1):299. PMID: 39994346
  7. World Anti-Doping Agency. 2026 Prohibited List, S0 Non-approved substances. wada-ama.org

Sources last reviewed October 2026.

B
Evidence grade B · Human RCTsWhat this means

AICAR (as the drug acadesine) has been tested in randomized human trials, including a 3,080-patient heart surgery trial stopped for futility, but it is not approved for any use and has no randomized trials for metabolic or performance goals[1,3].

A small nucleoside, not a peptide, that cells convert into an AMP look-alike to flip on the energy sensor AMPK; famous as a mouse "exercise pill" but unproven in people and banned in sport.

Overview

AICAR (AICA riboside, developed as the drug acadesine) is a small nucleoside molecule, not a peptide. Inside cells it is converted to ZMP, which mimics AMP, the signal cells use to say they are running low on energy, and so activates the enzyme AMPK[1]. It became famous in 2008 when four weeks of AICAR made sedentary mice run 44% farther, earning it the nickname "exercise in a pill"[2].

Human evidence tells a quieter story. As acadesine it was tested for decades to protect the heart during bypass surgery, and a 3,080-patient trial found no benefit[3]. Short infusion studies in healthy and diabetic men showed modest effects on blood sugar[4,5]. No human study has shown improved endurance, fat loss or longevity, and it has been banned in sport since 2012[6].

Faking a low-fuel warning lightAMPK works like a car's low-fuel light: when it comes on, the cell stops building and starts burning and conserving. AICAR does not add fuel or burn anything itself. It tricks the sensor into lighting up by impersonating the molecule that normally signals an empty tank, though it also bumps into several other switches on the dashboard.

Mechanism of Action

AICAR enters cells through adenosine transporters and is phosphorylated by adenosine kinase into ZMP (AICA ribonucleotide), an analog of AMP[1]. ZMP binds AMPK much as AMP does, switching on a kinase that pushes cells toward glucose uptake and fat burning while dialing down energy-costly processes like fat and protein synthesis. In mouse muscle, AICAR raised phosphorylation of AMPK and its target ACC and switched on dozens of oxidative-metabolism genes; this gene effect depended on the receptor PPARδ, because it disappeared in PPARδ-deficient muscle cells[2].

AICAR is a blunt tool. ZMP is roughly 40 to 50 times less potent than AMP at activating AMPK, so it must build up to high levels, where it also alters other AMP-sensitive enzymes and interferes with purine and pyrimidine metabolism[1]. A systematic review found many effects once credited to AMPK, including cell-cycle arrest in cancer cells, persist in cells lacking AMPK entirely[1]. In humans, healthy men's muscle took up more glucose after AICAR infusion with no measurable rise in AMPK activity, underscoring that the pathway is not simple[4].

What the Research Shows

Human studies
  • RED-CABG phase 3 RCT, JAMA 2012 (n=3,080 intermediate to high-risk bypass patients, IV acadesine vs placebo): death, stroke or severe heart failure by day 28 occurred in 5.1% vs 5.0% (odds ratio 1.01). The trial was stopped early for futility after enrolling 3,080 of a planned 7,500[3].
  • Infusion study in healthy men, Diabetes 2007 (n=29, single session): muscle glucose uptake rose 2.1-fold at 3 hours (vs 4.7-fold with cycling), but whole-body glucose disposal rose only about 7% and muscle AMPK activity did not change[4].
  • Infusion study in type 2 diabetes, Diabetologia 2008 (n=10 men, single session, no placebo arm): liver glucose output fell and blood glucose and free fatty acids declined; muscle glucose uptake did not change (P=0.29)[5].
  • Cancer trials: a phase I/II trial in chronic lymphocytic leukemia found an acceptable safety profile at its highest tolerated level, while a later trial in myelodysplastic syndrome and acute myeloid leukemia was stopped for serious kidney toxicity[1].
  • No controlled human trial has tested AICAR for endurance, body composition or aging.
Animal studies
  • Sedentary mice, 4 weeks: AICAR increased treadmill running distance by 44% and running time by 23% compared with untreated mice[2].
  • Mice, 6 days: AICAR switched on 32 oxidative-metabolism genes in thigh muscle, 30 of which overlapped with genes activated by the PPARδ pathway[2].
Cell & mechanistic
  • Leukemia, glioma and AMPK-knockout cells: AICAR halted cell growth even without AMPK, by disrupting nucleotide synthesis and the cell cycle, showing that many of its lab effects are AMPK-independent[1].
What This Could Mean in Practice

The "exercise pill" reputation rests on one mouse study[2]. In people, AICAR has only been given as a hospital IV infusion, it is poorly absorbed by mouth (under 5% in one report), and the largest trial found no benefit for its intended heart-protection use[1,3]. Short studies show modest, short-lived effects on blood sugar[4,5]. There is no human evidence that it builds endurance, burns fat or slows aging, and athletes face sanctions for using it[6].

Safety & Side Effects
  • In the 3,080-patient bypass trial, acadesine did not increase the composite of death, stroke or severe heart failure versus placebo[3].
  • Kidney toxicity: a leukemia trial was halted because of serious kidney toxicity at high exposures[1].
  • Because ZMP disrupts purine and pyrimidine metabolism and halts dividing cells in the lab, effects on rapidly dividing human tissues over longer use are a concern without data[1].
  • No long-term safety data exist for repeated self-administration outside hospital settings; human exposure has been limited to short IV infusions[1].

Open Questions

  • Whether any endurance or metabolic benefit seen in mice occurs in humans has never been tested in a controlled trial[2].
  • How much of AICAR's activity actually runs through AMPK versus other pathways remains unsettled[1,4].
  • Effects of repeated use over months, including on kidneys, blood cells and cancer risk, are unknown[1].
  • Products sold outside clinical trials are untested for purity and identity, and oral forms are barely absorbed[1].

Regulatory Status

Not approved by the FDA or EMA for any indication; development as acadesine for heart surgery stalled after the RED-CABG futility result[1,3]. Prohibited in sport under WADA class S4 (hormone and metabolic modulators, AMPK activators), banned at all times and listed since 2012[6].

Related Compounds

MOTS-CSLU-PP-332NAD+
References (6)
  1. Višnjić D, Lalić H, Dembitz V, et al. AICAr, a widely used AMPK activator with important AMPK-independent effects: a systematic review. Cells. 2021;10(5):1095. PMID: 34064363
  2. Narkar VA, Downes M, Yu RT, et al. AMPK and PPARδ agonists are exercise mimetics. Cell. 2008;134(3):405-15. PMID: 18674809
  3. Newman MF, Ferguson TB, White JA, et al. Effect of adenosine-regulating agent acadesine on morbidity and mortality associated with coronary artery bypass grafting: the RED-CABG randomized controlled trial. JAMA. 2012;308(2):157-64. PMID: 22782417
  4. Cuthbertson DJ, Babraj JA, Mustard KJ, et al. 5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside acutely stimulates skeletal muscle 2-deoxyglucose uptake in healthy men. Diabetes. 2007;56(8):2078-84. DOI: 10.2337/db06-1716
  5. Boon H, Bosselaar M, Praet SF, et al. Intravenous AICAR administration reduces hepatic glucose output and inhibits whole body lipolysis in type 2 diabetic patients. Diabetologia. 2008;51(10):1893-900. DOI: 10.1007/s00125-008-1108-7
  6. German Sport University Cologne, Institute of Biochemistry (WADA-accredited laboratory). S4 Hormone and metabolic modulators (summary of the WADA Prohibited List). dshs-koeln.de

Sources last reviewed October 2026.

D
Evidence grade D · Animal onlyWhat this means

The only disease-model evidence is a single rat prostatitis study, plus lab work on white blood cells; no human trials have been published[1,2].

A four-amino-acid synthetic peptide from Russian bioregulator research, aimed at the prostate, with one rat study and some cell work behind it and no human trials.

Overview

Prostamax is a synthetic tetrapeptide made of lysine, glutamic acid, aspartic acid and proline, usually written Lys-Glu-Asp-Pro (KEDP)[1,3]. It belongs to the family of short "peptide bioregulators" developed by Vladimir Khavinson's group in St. Petersburg, which pairs each small peptide with a target organ[2,3]. It should not be confused with Prostatilen (Samprost), an older Russian drug made from a mixture of peptides extracted from cattle prostate, which has its own separate clinical literature[4].

The published evidence is thin. In one rat study of chronic, non-infectious prostate inflammation, Prostamax reduced scarring and preserved the gland's lining better than a saw palmetto extract or the prostate extract Samprost[1]. In a lab study of white blood cells from people aged 75 to 88, it loosened tightly packed chromatin[2]. Most of this work comes from one research network, often in Russian journals. No human trials or independent replications, including in 2025, were found.

A targeted note for one organThe bioregulator idea is that each tiny peptide works like a note addressed to one organ, reminding its cells which genes to keep active. Prostamax is the note addressed to the prostate. The theory is the developers' own, and no study has shown the note reaching the human prostate or changing how it ages.

Mechanism of Action

The developers propose that KEDP, like their other short peptides, acts on gene regulation rather than on a hormone receptor. Their 2021 systematic review groups KEDP with peptides that contain a mix of acidic and basic amino acids and reports that such peptides change how stably double-stranded DNA holds together in test-tube melting experiments[3]. In lymphocytes taken from people aged 75 to 88, Prostamax and four related peptides activated ribosomal genes and released genes silenced by age-related chromatin condensation; Prostamax also decondensed a region of chromosome 1[2].

No study has identified a prostate-specific target for Prostamax, and none has shown that it concentrates in prostate tissue. The tissue link comes from the developers' design concept rather than from binding or distribution data[2,3]. In the rat study, the effects were measured as structural changes under the microscope (collagen, epithelium, gland density), not as changes in urinary flow, hormone levels or symptoms[1]. How a peptide this small survives digestion or circulation long enough to act has not been studied in published pharmacokinetic work.

What the Research Shows

Human studies
  • No human clinical trials of Prostamax have been published in peer-reviewed literature. Clinical studies of the cattle-prostate extract Prostatilen do not apply to this synthetic tetrapeptide[4].
Animal studies
  • Rats, surgically induced chronic aseptic prostatitis (60 male Wistar rats, 15 days of treatment starting a month after surgery): untreated rats had 3.9 times more collagen (scar) fiber than baseline; Prostamax cut collagen area more than 2.5-fold, back to baseline. It prevented a loss of up to 28% in epithelial area, which a saw palmetto extract and Samprost did not. Histology used at least 5 animals per group, and the paper appeared in a small open-access journal[1].
Cell & mechanistic
  • Lymphocytes from people aged 75-88: Prostamax activated ribosomal genes, decondensed chromatin and decondensed pericentromeric chromatin on chromosome 1[2].
  • Purified DNA: KEDP is reported to alter double-stranded DNA melting temperature and stability[3].
What This Could Mean in Practice

Prostamax remains an experimental peptide with one animal disease study and some laboratory work behind it[1,2]. The rat findings suggest less scarring in an artificial model of prostate inflammation, but that is a long way from showing relief of prostatitis, better urinary flow or protection against prostate enlargement in men. No human data exist to judge benefit or harm. Men with prostate symptoms have established, tested options, and this compound has not been compared with them in people.

Safety & Side Effects
  • No human safety data, adverse-event reports or long-term studies of Prostamax have been published in peer-reviewed literature.
  • The rat study did not report safety outcomes[1].
  • Peptides that may change gene activity in the prostate raise unanswered questions for men with prostate cancer or elevated PSA; no data address this.
  • Products sold under this name are unregulated, so identity, purity and sterility are not assured.

Open Questions

  • Whether the single rat prostatitis result can be repeated in another laboratory[1].
  • Whether Prostamax reaches prostate tissue at all after being swallowed or injected.
  • Whether chromatin changes seen in lab-dish white blood cells mean anything for living tissue[2].
  • Whether it affects prostate cancer risk in either direction.

Regulatory Status

Not approved by the FDA, the EMA or another major regulator for any use. It was not among the peptides reviewed at the FDA's July 2026 Pharmacy Compounding Advisory Committee meeting, which considered the related Khavinson-group peptide epitalon[5]. Prostamax is not named individually on the WADA Prohibited List, which separately bars substances not approved for human therapeutic use.

Related Compounds

EpitalonCortagenPinealon
References (5)
  1. Borovskaya T, Pakhomova A, Vychuzhanina A, et al. Experimental studying of the drug efficiency Prostamax in the therapy of chronic aseptic prostatitis and its complications. Mod Res Inflamm. 2013;2(3):54-58. DOI: 10.4236/mri.2013.23007
  2. Khavinson VK, Lezhava TA, Malinin VV. Effects of short peptides on lymphocyte chromatin in senile subjects. Bull Exp Biol Med. 2004;137(1):78-81. DOI: 10.1023/B:BEBM.0000024393.40560.05
  3. Khavinson VK, Popovich IG, Linkova NS, et al. Peptide regulation of gene expression: a systematic review. Molecules. 2021;26(22):7053. PMID: 34834147
  4. Kuzmin IV, Borovets SY, Gorbachev AG, et al. Prostatic bioregulatory polypeptide prostatilen: pharmacological properties and 30-year experience of clinical application in urology. Urology Reports (St. Petersburg). 2020;10(3):243-258. DOI: 10.17816/uroved42472
  5. U.S. Food and Drug Administration. FDA Briefing Document: Pharmacy Compounding Advisory Committee meeting, July 23-24, 2026 (epitalon evaluation). 2026. fda.gov

Sources last reviewed October 2026.

D
Evidence grade D · Animal onlyWhat this means

Evidence is limited to cultured cells plus a few mouse experiments from one research network; no human trials of PNC-27 have been published[3,7].

A laboratory peptide built from a fragment of the p53 protein that punctures cultured tumor cell membranes, studied only in cells and mice, never in people.

Overview

PNC-27 is a 32-amino-acid synthetic peptide made of two pieces: a stretch copied from the p53 tumor-suppressor protein (residues 12 to 26, the part that docks onto HDM-2, the human version of MDM-2) joined to a short membrane-residency leader sequence that helps the peptide reach membranes[8]. It came out of academic laboratories at SUNY Downstate and collaborating institutions, where the parent peptide family (PNC-27, PNC-28, and the control peptide PNC-29) was first described in breast cancer cell cultures[1].

The published work is preclinical. Cultured tumor lines from breast, pancreatic, colon, cervical and leukemic origin are reported to rupture within hours of exposure, while untransformed cells in the same experiments are reported to survive[1,3,6,10]. A handful of mouse experiments have been done, mostly with the shorter analog PNC-28[2]. Nothing here establishes that the peptide treats cancer in a person: there are no clinical trials, no pharmacokinetic data in humans, and no safety data in humans.

A dock that only broken boats haveHealthy cells keep the HDM-2 protein tucked away inside. The tumor lines in these experiments are reported to display some of it on the outside wall, like a dock bolted to the hull. PNC-27 is shaped to tie up at that dock, and the researchers propose that once several of them tie up side by side they tear a hole in the hull. Cells with no dock are left floating.

Mechanism of Action

The p53 segment of PNC-27 folds into roughly the same shape that p53 itself adopts when it binds HDM-2, which is what led the original group to predict HDM-2 as the target[3]. Their model is not the usual one for p53-based drugs. Most MDM-2 inhibitors work inside the cell, freeing p53 from degradation. PNC-27 is instead proposed to act at the plasma membrane: the investigators report HDM-2 at the membrane of various cancer lines but not several untransformed lines, report that fluorescently tagged PNC-27 colocalizes with it, and report that transfecting full-length HDM-2 with a membrane-localization signal into untransformed MCF-10-2A breast epithelial cells made those cells susceptible[3]. Death in these experiments is necrotic (membrane rupture and LDH leakage) rather than apoptotic, and it proceeds in cells lacking functional p53[1,5].

Follow-up work tried to pin down the pore. Confocal imaging with a fluorophore on each end suggested the intact peptide, not a fragment, is what accumulates at the membrane of MCF-7 cells[4]. Immuno-electron microscopy reported gold-labeled PNC-27 and HDM-2 together in ring-shaped structures at the cell surface, with no such structures in untransformed fibroblasts[8]. A later paper reported that a monoclonal antibody against the p53-binding region of HDM-2 (residues 1 to 109) blocked the killing, and that treated cells also lost mitochondrial dye retention, suggesting the peptide reaches mitochondrial membranes too[9]. All of this comes from one collaborating group, so the mechanism has not been independently reproduced.

What the Research Shows

Human studies
  • No clinical trials of PNC-27 have been published, and no human pharmacokinetic, dosing or safety data exist. Every published result is from cultured cells or mice[3,7,8].
  • Claims that PNC-27 has worked in patients do not trace to any published trial. The phrase "primary human tumors" in this literature refers to tumor samples tested in the laboratory, not to treated patients[8].
Animal studies
  • Nude mice, pancreatic cancer xenografts (shorter analog PNC-28, not PNC-27): a 2-week intraperitoneal course destroyed tumors transplanted at the same time, blocked growth of tumors implanted at a remote site during treatment and for 2 weeks after, and shrank already-established tumors, which then regrew more slowly than with the control peptide[2].
  • Nude mice, CT-26 colon cancer peritoneal carcinomatosis: after tumors were established, daily intraperitoneal PNC-27 for 14 days produced histologic necrosis of tumor nodules (average 22 nodules scored per animal, blinded rater) without reported necrosis of normal tissue. The paper reports no tumor-size numbers, no group sizes and no statistics for the in vivo arm[7].
  • No published rodent toxicology, carcinogenicity or reproductive studies of PNC-27 were located, and no survival study has been reported[2,7].
Cell & mechanistic
  • Acute myeloid leukemia lines: necrosis and LDH release within 4 hours, with 50% inhibitory concentrations of 4.7 µM (U937), 83.9 µM (OCI-AML3) and 91.1 µM (HL-60), a nearly 20-fold spread across three lines of the same disease. Normal mononuclear cells showed no cytotoxicity[6].
  • Cervical cells: 50% inhibitory concentration of 12.4 µM in HTB-35 (SiHa) squamous carcinoma cells, with no comparable effect on PCS-480 normal cervical cells; membrane HDM-2 was detected on the cancer line only[10].
  • Colon cancer lines: across six tumor lines, 35% to 76% of cells carried the CD44 stem-like marker and 47% to 92% carried membrane H/MDM-2; PNC-27 colocalized with membrane HDM-2 in cancer cells but not in the normal CCD-18Co line, and killed by necrosis rather than apoptosis[7].
What This Could Mean in Practice

In practice this means very little is known. PNC-27 is a mechanism-probing laboratory tool, and the honest summary is that an interesting idea (attacking a protein displayed on the outside of tumor cells) has been reported mostly by a single research network, in cultured cells and a few mouse tumor models, with no human study of any kind[3,7,8]. The concentrations that killed cells in culture varied roughly 20-fold between lines of the same cancer type[6]. Nothing published supports its use to treat any disease in people, and no regulator anywhere has reviewed it.

Safety & Side Effects
  • No human safety data exist. There are no published trials, no tolerability reports and no adverse-event data in people[3,7].
  • Selectivity rests on one proposed marker. The claim that normal cells are spared depends on membrane HDM-2 being absent from healthy tissue, which has been assessed in a limited panel of cultured lines, not across human organs[3,10].
  • Mechanism is lytic, not targeted in the usual sense. The peptide is reported to kill by rupturing membranes[1,5], and pore-forming peptides as a class carry risks of hemolysis and off-target membrane damage that have not been characterized for PNC-27.
  • Mitochondrial involvement is reported but unquantified. One paper reports PNC-27 binding mitochondrial membranes and disrupting them, which raises questions about tissues rich in mitochondria that no study has answered[9].
  • No regulatory toxicology package. No published repeated-dose, genotoxicity, carcinogenicity or reproductive studies were located for PNC-27[2,7].
  • Research-grade material is not a medicine. Material sold for laboratory use is not manufactured, tested or labeled to any standard intended for human administration.

Open Questions

  • Whether the findings reproduce outside the originating research network. Nearly all PNC-27 papers share overlapping authorship, and several authors have held positions with a company formed around the peptide, which the papers do not always list as a competing interest[8].
  • Whether membrane HDM-2 really is restricted to malignant cells in living human tissue, which is the entire basis for the selectivity claim[3].
  • What happens to the peptide in a body: no absorption, distribution, stability or half-life data in any species have been published.
  • Whether the mouse tumor responses mean anything for human disease. The in vivo work used intraperitoneal peptide against intraperitoneal tumors, reported no quantitative endpoints, and included no survival analysis[2,7].

Regulatory Status

PNC-27 is not approved by the FDA, EMA or any other major regulator for any use, and no registered clinical trial of it was located. It is not a recognized compounding substance. Because it has no approval from any governmental regulatory health authority for human therapeutic use, it falls under WADA class S0 (non-approved substances), prohibited in sport at all times[11].

Related Compounds

FOXO4-DRIHumaninNAD+
References (11)
  1. Do TN, Rosal RV, Drew L, et al. Preferential induction of necrosis in human breast cancer cells by a p53 peptide derived from the MDM2 binding site. Oncogene. 2003;22(10):1431-44. PMID: 12629507
  2. Michl J, Scharf B, Schmidt A, et al. PNC-28, a p53-derived peptide that is cytotoxic to cancer cells, blocks pancreatic cancer cell growth in vivo. Int J Cancer. 2006;119(7):1577-85. PMID: 16688716
  3. Sarafraz-Yazdi E, Bowne WB, Adler V, et al. Anticancer peptide PNC-27 adopts an HDM-2-binding conformation and kills cancer cells by binding to HDM-2 in their membranes. Proc Natl Acad Sci U S A. 2010;107(5):1918-23. PMID: 20080680
  4. Sookraj KA, Bowne WB, Adler V, et al. The anti-cancer peptide, PNC-27, induces tumor cell lysis as the intact peptide. Cancer Chemother Pharmacol. 2010;66(2):325-31. PMID: 20182728
  5. Davitt K, Babcock BD, Fenelus M, et al. The anti-cancer peptide, PNC-27, induces tumor cell necrosis of a poorly differentiated non-solid tissue human leukemia cell line that depends on expression of HDM-2 in the plasma membrane of these cells. Ann Clin Lab Sci. 2014;44(3):241-8. PMID: 25117093
  6. Thadi A, Lewis L, Goldstein E, et al. Targeting membrane HDM-2 by PNC-27 induces necrosis in leukemia cells but not in normal hematopoietic cells. Anticancer Res. 2020;40(9):4857-67. PMID: 32878773
  7. Thadi A, Morano WF, Khalili M, et al. Molecular targeting of H/MDM-2 oncoprotein in human colon cancer cells and stem-like colonic epithelial-derived progenitor cells. Anticancer Res. 2021;41(1):27-42. PMID: 33419797
  8. Sarafraz-Yazdi E, Mumin S, Cheung D, et al. PNC-27, a chimeric p53-penetratin peptide binds to HDM-2 in a p53 peptide-like structure, induces selective membrane-pore formation and leads to cancer cell lysis. Biomedicines. 2022;10(5):945. DOI: 10.3390/biomedicines10050945
  9. Krzesaj P, Adler V, Feinman RD, et al. Anti-cancer peptide PNC-27 kills cancer cells by unique interactions with plasma membrane-bound hdm-2 and with mitochondrial membranes causing mitochondrial disruption. Ann Clin Lab Sci. 2024;54(2):137-48. PMID: 38802154
  10. Krzesaj PK, Seydafkan S, Miller AI, et al. HDM-2-targeting peptide PNC-27 kills cervical cancer cells but not normal cervical cells. Ann Clin Lab Sci. 2025;55(3):347-53. PMID: 40750238
  11. World Anti-Doping Agency. 2026 Prohibited List, S0 Non-approved substances (effective 1 January 2026). wada-ama.org

Sources last reviewed October 2026.

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