Longevity
FOXO4-DRI
aka FOXO4 D-Retro-Inverso · FOXO4-DRI peptide · foxo4 · foxo4-dri · foxo4 dri · foxo4dri · fox04-dri · fox04 · fox o4 · foxo4 peptide · senolytic peptide · zombie cell peptide
Grade
A lab-designed peptide that kills worn-out 'zombie' (senescent) cells in mice and lab dishes, sold online as an anti-ageing drug despite never being tested in a single human trial.
- Class
- Synthetic D-retro-inverso peptide (built from mirror-image 'D' amino acids in reversed order), designed to block the FOXO4-p53 interaction
- Evidence
- Grade D · Animal data only
- Sport / WADA
- Prohibited at all times under S0 (non-approved substances). It is not named on the WADA Prohibited List, but S0 bans any substance not covered by another section that has no current approval by any government health authority for human therapeutic use, and FOXO4-DRI is an experimental compound with no such approval anywhere.
- Last reviewed
- 2026-10
Grade D · Animal data only
Why this grade
All the evidence comes from mice and from cells in lab dishes. No human trial has been registered or published, and nothing is known about how it behaves in the human body. The 2017 mouse results were striking, but they have not been tested in people.
What is it?
Why people buy it
People buy it to slow ageing. Sellers say it clears out old, worn-out cells, sometimes called 'zombie cells'.
What we actually know
- •Old cells that stop dividing but do not die are called senescent cells. They build up as we age.
- •In one 2017 study, it cleared these cells in old mice. Their fur, fitness and kidneys improved.
- •Later work in mice and in lab dishes found similar cell-clearing effects.
- •It has never been tested in people. It is not a licensed medicine in the UK, or anywhere else.
What might happen
- •There is no proof it slows ageing in people. Nobody has tried it in a proper study.
- •Nobody knows how long it lasts in the body, where it goes or what a safe amount is.
- •It works by telling cells to die. Nobody knows if it could harm healthy cells in people.
- •It is sold online as 'not for human use'. Nobody checks what is really in the bottle.
- •In sport, it is banned at all times. Unapproved drugs count as banned.
Bottom line
A clever idea that worked in old mice. In people, it is completely untested.
Know someone taking this?
Send on WhatsAppThink of a garden weedkiller that, in a greenhouse trial, pulled out the old dead-headed plants and left the healthy ones standing. It is an impressive demonstration. Nobody has yet sprayed it on a real garden to see what else it hits.
How is it meant to work?
In senescent cells, the transcription factor FOXO4 binds p53 and keeps it in the nucleus in a state where it does not trigger apoptosis, which helps the damaged cell survive. FOXO4-DRI mimics the FOXO4 surface that binds p53 and competes for it, releasing p53, which then moves out of the nucleus and sets off programmed cell death. Because healthy dividing cells rely far less on this FOXO4-p53 interaction, the effect in mouse and cell studies was largely selective for senescent cells. The D-retro-inverso design (mirror-image amino acids in reversed order) is meant to keep the same binding shape while resisting breakdown by enzymes.
What's it studied for?
Research contexts. Not proven uses, and not recommendations.
Does the human evidence stack up?
None. No human trial of FOXO4-DRI has been registered on ClinicalTrials.gov or published. The only human material studied is cells in a dish (cartilage cells from donors in Huang et al. 2021). There are no human data on safety, dosing, how long it lasts in the body or whether it does anything useful. Online anti-ageing claims rest entirely on mouse and cell studies.
What could go wrong?
- !No human safety data of any kind, so short- and long-term risks are unknown.
- !It works by triggering cell death. Whether it spares healthy human cells at the amounts people inject is untested.
- !Nothing is known about how it is absorbed, distributed or cleared in humans.
- !Grey-market product purity and identity are unverified, so what is in the vial may not match the label.
- !Injecting unregulated products carries infection and contamination risks.
- !Marketing as a proven 'zombie cell' cleaner for people far outruns the evidence, which is mouse and lab-dish only.
Is it legal in the UK?
FOXO4-DRI is not a licensed medicine in the UK and has no MHRA marketing authorisation for any use. It is not a controlled drug. It is sold online as an unlicensed 'research chemical' labelled 'not for human consumption' to sidestep the Human Medicines Regulations 2012; selling or supplying it as a treatment for people would breach those rules. There is no lawful route to obtain it in the UK as a medicine.
Sources
- 01Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging — Baar MP, Brandt RMC, Putavet DA, et al. (de Keizer PLJ senior author), Cell (2017)
The original FOXO4-DRI paper. Mouse and cell work only: restored fitness, fur density and kidney function in fast-ageing and naturally aged mice.
- 02FOXO4-DRI alleviates age-related testosterone secretion insufficiency by targeting senescent Leydig cells in aged mice — Zhang C, Xie Y, Chen H, et al., Aging (Albany NY) (2020)
Independent follow-up in aged mice and cultured cells. Not human.
- 03Senolytic Peptide FOXO4-DRI Selectively Removes Senescent Cells From in vitro Expanded Human Chondrocytes — Huang Y, He Y, Makarcyzk MJ, Lin H, Frontiers in Bioengineering and Biotechnology (2021)
Donor human cartilage cells in a dish, not people. Senescent cells were removed but cartilage-forming ability did not improve.
Related
Before you trust a vial
Peptides are freeze-dried for a reason. If you have seen FOXO4-DRI sold pre-mixed in a ready-to-use pen or syringe, here is why that is a red flag for potency, sterility and dosing.
Storage & stability →Stay posted
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