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FOXO4-DRI17 residuesLTLRKEPASEIAQSILEEach bubble = one amino acid. Size = residue mass. Color = chemical class.Also known as: FOXO4-DRI, FOXO4 DRI, ES2
Aged mice regrew fur, ran longer, and showed normalized kidney function after three injections over six days. That was the 2017 Cell paper from Peter de Keizer's lab at Erasmus MC [1]. FOXO4-DRI is a D-retro-inverso peptide built to disrupt the FOXO4-p53 interaction that keeps senescent cells alive. It triggers apoptosis in those damaged "zombie" cells while leaving healthy tissue alone. No human trial has been completed. All dosing is extrapolated from mouse data using allometric scaling. Community adoption sits under 50 meaningful reports across Reddit and longevity forums, largely because cost per course runs $80 to $750 depending on dose. This is a compound you take on mechanistic faith, not measurable outcomes.
Three injections cleared enough senescent cells to restore kidney function in aged mice. That single finding from the Baar et al. Cell paper (2017)[1] put FOXO4-DRI on the longevity map. FOXO4-DRI (CAS pending; molecular weight approximately 2870.2 Da) is an 18-residue D-retro-inverso peptide derived from the p53-binding domain of FOXO4. D-retro-inverso means D-amino acids arranged in reverse order. The result is a peptide that mimics the original binding surface but resists protease degradation far better than any standard L-form sequence. The mechanism is targeted. In senescent cells, FOXO4 binds p53 in the nucleus and blocks apoptosis. FOXO4-DRI competes for that binding site, displaces endogenous FOXO4, and frees p53 to translocate to the mitochondria. There it activates BAX and caspase-3, triggering programmed cell death. Healthy cells don't upregulate FOXO4, so they're spared. A 2025 structural NMR study confirmed the p53 TAD2 binding interaction that underpins this selectivity. Practical use is thin. Fewer than 50 meaningful community reports exist across r/Peptides, r/longevity, and r/nootropics. Most users run a conservative 1 to 3 mg pulse (3 doses over 6 days) followed by 3 to 6 months off. That dosing sits well below the allometric human equivalent of approximately 25 mg per injection derived from the mouse protocol of 5 mg/kg IP. No consumer-grade test can measure senescent cell clearance, so there's no feedback loop to confirm anything worked. Cleara Biotech, the spinoff company, is targeting first-in-human trials of optimized derivatives (CL04177, CL04183) around 2027. Until then, FOXO4-DRI sits firmly in the experimental category.
Senescent cells are damaged cells that stopped dividing but refuse to die. They accumulate with age and secrete a cocktail of inflammatory cytokines called the SASP (senescence-associated secretory phenotype), including IL-6 and IL-8. That chronic low-grade inflammation drives tissue deterioration and contributes to age-related disease. What keeps these cells alive is a specific protein interaction. FOXO4 is upregulated in senescent cells and binds directly to p53 inside the nucleus. That complex sequesters p53, preventing it from doing its normal job of triggering apoptosis. Senescent cells essentially hijack the FOXO4-p53 axis to survive. FOXO4-DRI is a cell-permeable peptide that competes with endogenous FOXO4 for the p53 binding site. Once it displaces FOXO4, phosphorylated p53 is excluded from the nucleus. It translocates to the mitochondria. There it activates the intrinsic apoptosis pathway through BAX activation and caspase-3 cleavage. The cell dies. Selectivity comes from expression patterns. FOXO4 is selectively upregulated in senescent cells, not in healthy proliferating tissue. Baar and colleagues confirmed this in the 2017 Cell paper. A 2025 NMR structural study pinned down the exact binding interface: p53's TAD2 domain. The D-retro-inverso backbone is the engineering trick. D-amino acids in reverse order produce a mirror-image surface that proteases can't easily degrade. Standard L-peptides last 2 to 4 hours in circulation; the DRI form likely persists 48 hours or longer, though no human PK study confirms this.
Selectively induces apoptosis in senescent cells by disrupting FOXO4-p53 interaction in cell and mouse models; mechanism confirmed by 2025 structural NMR study (p53 TAD2 binding); no human trial data
Baar et al., Cell 2017 (PMID 28340339): fitness restoration, kidney function normalization, fur regrowth in aged mice
Zero completed human trials; all dosing extrapolated from mouse IP data via allometric scaling; no human PK, bioavailability, or safety data; Cleara Biotech Phase I (optimized derivatives) targeting 2027+
Niche use; high mechanistic interest, very low adoption; used as senolytic pulse with no measurable consumer endpoint; cost is primary adoption barrier
Community has adopted the pulse-and-wait structure consistent with senolytic biology. However, community doses (1–3 mg) are far below the mouse-derived allometric HED (~25 mg). Some users still run continuous weekly protocols with no scientific basis: a critical misapplication of the senolytic paradigm.
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 1mg | EOD x3 doses (6-day pulse) |
| Moderate | 3mg | EOD x3 doses (6-day pulse) |
| Aggressive | 25mg | EOD x3 doses (6-day pulse) |
The big practical issue with FOXO4-DRI is dosing unit confusion. All community protocols use milligrams (mg). Vendor vials come in 5 mg and 10 mg sizes. The site's dosing tiers list 500 mcg and 1000 mcg, which are 0.5 mg and 1 mg. Triple-check your math before injecting because a 1000x error between mcg and mg is a real risk that has been flagged in community discussions. Reconstitution math for a 10 mg vial: add 2 mL bacteriostatic water to get a concentration of 5 mg/mL. For a 1 mg dose, that's 0.2 mL, which reads as 20 IU on a U-100 insulin syringe. For 3 mg, you're drawing 0.6 mL (60 IU). At the full allometric dose of 25 mg, you need multiple vials and a standard syringe instead of an insulin syringe. For a 5 mg vial with 2 mL bacteriostatic water: concentration is 2.5 mg/mL. A 1 mg dose is 0.4 mL (40 IU). A 0.5 mg dose is 0.2 mL (20 IU). Store reconstituted vials at 2 to 8 degrees Celsius. Use within 7 to 14 days. Lyophilized powder keeps at minus 20 degrees Celsius long-term. Don't shake during reconstitution; swirl gently. Warm the solution to body temperature before injection to reduce nodule risk.
Senolytic pulse: 1 week on (6 injection days) followed by 12-24 weeks off to allow full senescent cell clearance and tissue remodeling. Biomarker assessment (inflammatory markers, kidney function) recommended before repeating. Most anecdotal protocols suggest 1-3 cycles per year at most.
FOXO4-DRI is not cycled for receptor desensitization or hormonal axis recovery. The rationale is senolytic biology: a brief pulse triggers apoptosis in the standing pool of senescent cells; the subsequent 3–6 month rest period allows macrophage-mediated efferocytosis to clear apoptotic debris and permits tissue remodeling. Re-dosing before clearance is complete may overwhelm efferocytosis capacity and create a secondary pro-inflammatory burden. Annual senescent cell accumulation then rebuilds the target pool, justifying 1–2 courses per year.
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Expected: Preclinical basis only: potential reduction in senescent cell burden; no measurable consumer endpoint; rely on subjective function and optional SASP cytokine panel
Monitor: SASP cytokine panel (IL-6, IL-8) + kidney function (creatinine, BUN) before course and at 8–12 weeks post-course. CBC + CRP before and at 4 weeks.
Pull 2 mL of bacteriostatic water into a syringe and inject it slowly down the inside wall of the vial. Do not aim the stream directly at the powder. Swirl gently until dissolved. A 10 mg vial with 2 mL gives you 5 mg per mL.
For 1 mg from a 5 mg/mL solution, draw 0.2 mL (20 IU on a U-100 insulin syringe). For 3 mg, draw 0.6 mL (60 IU). For the 0.5 mg beginner tier, draw 0.1 mL (10 IU).
Clean with an alcohol swab. Rotate between abdomen, outer thigh, and upper arm across your 3 doses. Use a 29 to 31 gauge insulin syringe for subcutaneous injection.
FOXO4-DRI is a large peptide. Pushing too fast increases nodule formation. Take 15 to 20 seconds per injection.
Schedule your 3 doses on alternating days: Day 1, Day 3, Day 5. Morning injection on an empty stomach is the typical community protocol.
The off-period is 3 to 6 months minimum. Your immune system needs time to process the cleared senescent cell debris through efferocytosis.
Store the reconstituted vial at 2 to 8 degrees Celsius between doses. Discard any remaining solution after 14 days.
Complementary antiaging mechanisms: epithalon targets telomere elongation while FOXO4-DRI reduces senescent cell burden. Used in longevity stacks for dual-pathway intervention.
Run epithalon 10 mg/day × 10 days before or after FOXO4-DRI course; do not co-administer simultaneously
Tissue remodeling and regenerative support post-senolysis; GHK-Cu promotes collagen synthesis and wound repair as newly cleared tissue space is remodeled
Introduce GHK-Cu 2–4 weeks into the off-period after FOXO4-DRI pulse
Cellular energy substrate support during active senescent cell clearance; NAD+ supports mitochondrial function and may support immune cell efferocytosis efficiency
Complementary senolytic mechanism via BCL-2 and tyrosine kinase pathways; D+Q has Phase 2 human data (IPF, CKD); some researchers combine with FOXO4-DRI for broader senotype coverage
D+Q: 100 mg dasatinib + 1,000 mg quercetin orally, 2 days on / 28 days off; do not administer simultaneously with FOXO4-DRI: separate by ≥2 weeks to avoid additive apoptotic burden
Overlapping BCL-2/BCL-xL senolytic mechanism; combined use may cause excessive apoptosis and severe thrombocytopenia (navitoclax depletes platelets by killing BCL-xL-dependent megakaryocytes)
Do not combineImpair macrophage-mediated efferocytosis: the immune mechanism that clears apoptotic senescent cell debris post-FOXO4-DRI; clearance failure may lead to secondary necrosis and inflammation
Do not combineDirect p53-pathway overlap with FOXO4-DRI mechanism; combined p53 activation may cause unpredictable apoptosis in non-senescent cells
Do not combineChemotherapy massively increases senescent cell burden; concurrent FOXO4-DRI could trigger overwhelming senolytic load and cytokine release; also p53 interactions are complex in actively treated cancer
Do not combinePricing updated 2026-04-09
No human clinical safety data exists for FOXO4-DRI. Zero completed trials. Zero formal adverse event reporting. Every safety signal below comes from animal models, mechanistic reasoning, or fewer than 50 community self-reports. That limitation matters more here than for most peptides. The most serious theoretical risk is cytokine release from rapid senolytic clearance. When large numbers of senescent cells undergo apoptosis simultaneously, the immune system must process the debris through macrophage-mediated efferocytosis. If clearance capacity is overwhelmed, apoptotic cells undergo secondary necrosis, releasing damage-associated molecular patterns (DAMPs) that trigger systemic inflammation. At the allometric human equivalent dose of approximately 25 mg, this risk is entirely uncharacterized. Even at community doses of 1 to 3 mg, some users report transient flu-like symptoms (fatigue, mild fever, joint aches) 12 to 72 hours post-injection. About 20% of community reports mention this effect. Injection site reactions are common with FOXO4-DRI specifically because it's an 18-residue peptide with higher molecular weight. Users report nodules or lumps at the injection site that typically resolve in 24 to 48 hours. Slow injection technique, warming the solution to body temperature, and diluting in 2 mL bacteriostatic water reduces nodule formation. The p53 pathway manipulation carries a real concern in anyone with active or undetected cancer. p53 is the most commonly mutated tumor suppressor gene. Altering its localization and activity in a setting where tumor biology is already disrupted could have unpredictable consequences. This is not a theoretical quibble; it's why Cleara Biotech's clinical program specifically targets mutant-p53 cancers with optimized derivatives. Long-term safety is entirely unknown. Annual senescent cell turnover, chronic effects of repeated senolytic pulses, and cumulative immune system impact have never been studied in any species beyond mice. Contraindications: pregnancy or breastfeeding (no reproductive data), active autoimmune disease, immunocompromised status (efferocytosis requires functional immunity), active cancer, severe hepatic or renal impairment, and children or adolescents (senescence plays different roles during development). Stop immediately for unexplained organ function changes, persistent injection site nodules, or any signs of systemic inflammatory response.
Verify FOXO4-DRI dosing and safety with a second opinion
D-retro-inverso synthesis (18 D-amino acids in reverse sequence) is technically demanding and expensive; many research peptide vendors lack the synthesis capability or QC infrastructure for consistent purity; no pharmacopeial standard exists; counterfeiting with cheaper L-form or truncated sequences is a documented risk in the grey market
| Test | When | Target |
|---|---|---|
| SASP cytokine panel (IL-6, IL-8) | Before course and at 8 weeks post-course | IL-6 <2 pg/mL, IL-8 <10 pg/mL (lab-dependent reference ranges); goal is reduction from pre-course baseline |
| Kidney function (creatinine, BUN, eGFR) | Before course and at 12 weeks post-course | Creatinine 0.7–1.2 mg/dL (male), 0.5–1.0 mg/dL (female); eGFR >60 mL/min/1.73m² |
| CBC with differential + CRP | Before course and at 4 weeks post-course | — |
| Physical function assessment (grip strength, 6-minute walk or stair climb) | Before course and at 12 weeks post-course | — |
Primary research endpoint for senolytic efficacy: SASP reduction reflects decreased senescent cell burden; also screens for pathological inflammatory response
Kidney function normalization was the key mouse study endpoint (Baar 2017); also monitors for any organ stress from senescent cell debris clearance
Rules out systemic inflammatory response from rapid senescent cell clearance; thrombocytopenia would suggest off-target platelet effect
Mirrors primary fitness endpoints from mouse studies; objective tracking; provides a structured personal data point in the absence of biomarker confirmation
Initial dosing phase. No immediate visible effects expected. Senescent cell apoptosis begins at the cellular level. Mild injection site reactions possible. Some users report transient flu-like symptoms as senescent cells are cleared.
Continued senolytic clearance during on-cycle. Inflammatory markers may transiently rise as senescent cells undergo apoptosis and are removed by the immune system. Energy levels and general well-being may begin to shift, though individual responses are highly variable.
Post-cycle recovery and tissue remodeling. The body processes debris from cleared senescent cells. In mouse models, functional improvements (activity, organ function) became apparent during this phase. Any benefits in humans remain unconfirmed.
Extended off-period allows full tissue adaptation. In animal studies, improvements in kidney function and physical fitness persisted well beyond the treatment window. Biomarker reassessment recommended before considering another cycle.
Days 1 through 6 (Active pulse): FOXO4-DRI distributes to tissues and binds the p53 TAD2 domain. It displaces endogenous FOXO4, freeing p53 to exit the nucleus and trigger apoptosis in senescent cells through BAX activation and caspase-3 cleavage. Most users feel nothing during this phase. A minority report mild headache or fatigue 24 to 48 hours post-injection. Injection site tenderness or small nodules are common and typically resolve within two days. Weeks 1 through 4 (Early off-period): The immune system starts clearing apoptotic debris through macrophage-mediated efferocytosis. SASP cytokines like IL-6 and IL-8 may spike briefly before dropping as dead cells are processed. Some community users report improved energy and clearer skin starting around weeks 2 to 3. Responses vary widely. Transient fatigue during active immune clearance is expected. Months 1 through 3 (Tissue remodeling): This is when mouse studies showed the payoff. Kidney function markers normalized. Fitness measures improved. Tissue progenitor cells moved into the niches left by cleared senescent cells. Community reports of improved energy, hair density, and skin quality cluster around weeks 6 to 10 post-course. None of this is controlled data. Months 3 through 6 and beyond (Extended off-period): The mouse data showed functional gains persisting long after treatment ended. Re-dosing too early may interrupt tissue remodeling. Experienced users reassess at 4 to 6 months with SASP cytokine panels and kidney function tests before considering another course. Most protocols call for 1 to 2 courses per year at most.
FOXO4-DRI distributes to tissues; binds p53 TAD2; displaces FOXO4; p53 excluded from nucleus → mitochondrial translocation → BAX activation → caspase-3 cleavage → senescent cell apoptosis begins
No perceptible effects for majority; minority report transient fatigue or mild headache 24–48h post-dose; injection site tenderness
Macrophage-mediated efferocytosis removes apoptotic senescent cells; SASP cytokines (IL-6, IL-8) may transiently rise then fall as dead cells are processed
Some users report improved energy, clearer skin, or reduced joint discomfort beginning week 2–3; responses are highly variable and uncontrolled
In mouse models, organ function improvements (kidney urea/creatinine normalization) and fitness restoration (grip strength, running capacity) emerged during this phase; tissue progenitors occupy cleared senescent niches
Subjective energy, hair density, and skin quality improvements most commonly reported at 6–10 weeks post-course; anecdotal; no controlled data
Longevity and functional gains persisted well beyond the treatment window in mouse studies; re-dosing too early may interrupt tissue remodeling
Most experienced users report course-to-course re-assessment at 4–6 months; no long-term human data; subjective benefit tracking is the only available tool
Source: Estimated from peptide pharmacokinetics; D-retro-inverso form extends duration vs. L-peptide. No direct human PK studies available.
Loading the interactive decay curve.
FOXO4-DRI is classified as a research chemical in the United States. It has no FDA approval, no IND application, and no scheduled drug classification. It's sold by research peptide vendors under "for research purposes only" labeling. Compounding pharmacies do not produce it. Cleara Biotech (Utrecht, Netherlands) holds patents on optimized FOXO4-DRI derivatives (CL04177, CL04183) and is targeting first-in-human Phase I trials for mutant-p53 cancers by 2027. Those compounds are not identical to the original Baar 2017 sequence sold by vendors. WADA does not currently list FOXO4-DRI by name. However, the broad "peptide hormones, growth factors, and related substances" category could theoretically apply. Athletes in tested sports should assume it carries risk. This content is for informational and research purposes only. It does not constitute medical advice. Consult a licensed healthcare provider before using any research compound. Peptide Schedule does not sell, distribute, or endorse the purchase of any peptide for human use.
Peptide Schedule Research TeamReviewed Apr 20265 Citations
