FOXO4-DRI
D-retro-inverso senolytic peptide targeting the FOXO4-p53 protein interaction
- Class
- Senolytic peptide
- Half-life
- Unknown in humans
- Route
- Subcutaneous (SubQ)
- Cadence
- Cycled (on/off)
- Evidence
- Animal data primarily
Overview
FOXO4-DRI is a synthetic peptide designed to selectively kill senescent cells — the 'zombie cells' that stop dividing but refuse to die, accumulate with age, and pump out inflammatory signals that damage surrounding tissue. It works by breaking the interaction between two proteins (FOXO4 and p53) that senescent cells use to stay alive. When that interaction is disrupted, p53 moves to the mitochondria and triggers apoptosis — but only in senescent cells, not healthy ones.
The peptide is built using D-amino acids arranged in reverse sequence (D-retro-inverso), which makes it resistant to the enzymes that would normally chew it up in minutes. This engineering trick is what allows it to work systemically after injection. The concept came from a 2017 Cell paper by Baar and colleagues at Erasmus University, showing that naturally aged mice treated with FOXO4-DRI regained fur density, kidney function, and physical fitness — a rare example of functional tissue restoration driven by targeted cell removal.
The catch: every bit of evidence is preclinical. No human trials, no safety data in people, no confirmed dosing. The research-market peptide is unregulated, purity varies wildly, and the people using it are essentially running their own n=1 experiments. The mouse data is strong and the mechanism is elegant, but the gap between promising rodent results and a proven human therapy is real.
Safety considerations
A few of the safety signals worth knowing — the full list, with dosing context and what to monitor, is inside AIx Core.
- Not approved for human use by any regulator. Sold in research markets as 'research use only' with no oversight of purity, peptide content, or sterility.
- Zero human safety data — no Phase 1 trials, no pharmacokinetic studies, no toxicology data in people. All published safety data are from mouse studies showing no overt toxicity at therapeutic doses.
- p53 is a tumor suppressor and master regulator of cell death. Any compound that modulates p53 carries theoretical risk of unintended effects in healthy cells or disruption of tumor surveillance. While selectivity for senescent cells is the design goal, off-target binding in humans is uncharacterized.
+ 3 more safety notes inside AIx Core →
Commonly monitored
Markers and signals people track when researching FOXO4-DRI.
- Complete blood count — theoretical concern for off-target apoptosis in immune cells under stress
- Liver enzymes (AST, ALT) — senolytic effects on liver function not characterized in humans
- Inflammatory markers (CRP, IL-6) — senescent cell clearance should reduce systemic inflammation if working
- Subjective energy, recovery, skin quality — anecdotal targets in self-experimentation
- Wound healing capacity — senescent cells play roles in acute wound repair; excessive clearance could impair this
Frequently asked questions
What is FOXO4-DRI?
D-retro-inverso senolytic peptide targeting the FOXO4-p53 protein interaction. FOXO4-DRI is a synthetic peptide designed to selectively kill senescent cells — the 'zombie cells' that stop dividing but refuse to die, accumulate with age, and pump out inflammatory signals that damage surrounding tissue. It works by breaking the interaction between two proteins (FOXO4 and p53) that senescent cells use to stay alive. When that interaction is disrupted, p53 moves to the mitochondria and triggers apoptosis — but only in senescent cells, not healthy ones.
How is FOXO4-DRI administered?
Subcutaneous (SubQ), typically cycled (on/off).
What is the half-life of FOXO4-DRI?
Unknown in humans — D-amino acid structure resists protease breakdown; half-life not characterized in humans.
Is FOXO4-DRI approved for human use?
FOXO4-DRI is investigational — not approved by the FDA, EMA, or MHRA for human use at the time of writing.
What does the evidence show for FOXO4-DRI?
Evidence tier: Animal data primarily. Baar 2017 (Cell, PMID 28340339) dosed naturally aged mice at 5 mg/kg IV every other day for 3 weeks. Treated mice showed restoration of fur density, improved renal function (BUN dropped from ~60 to ~40 mg/dL), and regained running-wheel fitness to levels seen in young mice.
What is commonly monitored when researching FOXO4-DRI?
Commonly tracked markers + signals: Complete blood count — theoretical concern for off-target apoptosis in immune cells under stress, Liver enzymes (AST, ALT) — senolytic effects on liver function not characterized in humans, Inflammatory markers (CRP, IL-6) — senescent cell clearance should reduce systemic inflammation if working, Subjective energy, recovery, skin quality — anecdotal targets in self-experimentation, Wound healing capacity — senescent cells play roles in acute wound repair; excessive clearance could impair this.
Open this in AIx Core for the full picture
Mechanism breakdown, receptor pathway diagram, full safety list, monitored items, source citations, and one-tap add-to-protocol. Free with any account.