Preclinical senolytic — no human outcomes established
An experimental peptide designed to remove certain aging or damaged cells that have stopped dividing.
5-minute readFull profile reviewed July 30, 2026
Evidence is explained by question. Dosing references show their own check dates.
60-second overview
FOXO4-DRI at a glance
Why people look into it, what studies found, and what is still unknown.
Why people look into it
Whether removing those cells improves age-related problems or tissue function.
What studies found
Cell and animal studies reported some benefits, but one study also found worse blood-vessel measures in selected models. No human administration study was identified.
What is still unclear
Human benefits, selectivity, cancer-related effects, and long-term safety are unknown. Removing these cells may help or harm depending on the setting.
About the evidence and review date
Educational information only. Evidence reviewed through July 30, 2026. Published studies, sponsor announcements, and trials without results are labeled separately. Evidence gaps apply to the specific finding beside them.
Research questions
Why people research it
Each label shows how much evidence supports that question.
Selective senescent-cell apoptosisAnimal or lab research
Cellular aging and tissue homeostasisAnimal or lab research
Vascular-aging researchAnimal or lab research
Fibrosis and extracellular-matrix researchAnimal or lab research
Reproductive agingAnimal or lab research
Human anti-aging or longevity benefitNot demonstrated
Human safety and effectivenessNot demonstrated
What studies show
What the evidence supports
The research behind the answer
No administered human study was identified. The closest human-derived evidence is laboratory or ex-vivo work in human fibroblasts, chondrocytes, endothelial cells, and keloid tissue.
See each finding and its sources (7)
Mechanistic rationale
FOXO4-DRI is an experimental D-retro-inverso, cell-penetrating peptide designed to interfere with the FOXO4-p53 protein interaction.
It is a research peptide, not a receptor agonist. The design combines a FOXO4-derived sequence with a cell-penetrating segment and reverses peptide direction and chirality to improve stability in experimental systems.
Commercial materials may differ in sequence, purity, counterion, aggregation, or formulation from research material used in published experiments.
Peer reviewedStructural characterization of p53 and FOXO4-DRI binding
Peer reviewedPeptide design and FOXO4-p53 competition experiments
No direct evidence located
Selected cell and mouse studies support a senolytic mechanism, but no administered human outcome study has established safety or effectiveness.
The closest human-derived evidence comes from cells and tissue studied outside the body, including fibroblasts, chondrocytes, and keloid organ cultures.
Human-derived cells are not human clinical exposure. They cannot establish pharmacokinetics, immune effects, organ toxicity, cancer risk, or clinical benefit.
Trial registryNo matching FOXO4-DRI interventional record identified
FOXO4-DRI has not been shown to slow human aging, extend human lifespan, or produce generalized rejuvenation.
Published findings describe specific laboratory systems and animal models. They do not establish a whole-body anti-aging treatment in people.
Aging is not one uniform cell state, and senescent cells can have both harmful and protective functions depending on tissue, timing, and disease context.
Trial registryNo matching human interventional trial identified
Senescent-cell clearance is context dependent and may be harmful in some tissues or diseases.
In rodent pulmonary-hypertension models, senescent-cell elimination was associated with pulmonary endothelial-cell loss and worse hemodynamic and remodeling measures.
The study cannot quantify human risk and included multiple clearance methods, but it directly challenges the assumption that removing senescent cells is universally beneficial.
Peer reviewedPulmonary endothelial-cell loss and worsened rodent outcomes
Animal study
Vascular-aging, pulmonary-fibrosis, fertility, cartilage, and keloid findings remain preclinical or ex vivo.
Each research direction used a different experimental system. None demonstrates a broadly transferable clinical effect.
Positive findings across multiple models do not establish one shared dose, route, treatment window, safety profile, or human indication.
No regulator-approved FOXO4-DRI dose, route, cycle, reconstitution, storage, or monitoring standard exists.
Animal injection protocols and laboratory concentrations describe experiments; they are not consumer instructions.
Systemic delivery, tissue distribution, immune response, degradation products, repeated exposure, and manufacturing quality have not been established in humans.
The FOXO4-p53 mechanism involves p53 redistribution and apoptosis rather than a simple removal of every cell expressing a senescence marker.
Published work describes a protein-interaction mechanism that depends on cellular state, p53 signaling, phosphorylation, uptake, and model-specific biology.
No universal biomarker or clinical test has been validated to predict which human cells would respond or whether clearance would be beneficial.
Peer reviewedp53 transactivation-domain binding and phosphorylation
Peer reviewedp53 redistribution and apoptosis experiments
Risks & unknowns
What needs caution
Reported side effects
Selected cell and mouse studies support a senolytic mechanism, but no administered human outcome study has established safety or effectiveness.
No direct evidence
Human-derived cells are not human clinical exposure. They cannot establish pharmacokinetics, immune effects, organ toxicity, cancer risk, or clinical benefit.
Missing reports do not establish safety. Findings apply to the product, route, amounts, population, comparison, and follow-up studied.
Side-effect frequency, study withdrawals, and gaps
How often side effects occurred
The available information does not reliably show how often particular side effects occur.
Evidence boundary
Under-detected or under-reported events must not be described as rare.
Why people stopped in studies
Relay has not verified which side effects led people to stop treatment in studies.
Evidence boundary
This is an evidence gap, not proof that discontinuations did not occur.
Warning information
Relay has not verified a compound-specific warning summary for this profile.
Evidence boundary
Not FDA approved; no registered human interventional FOXO4-DRI study was identified at the evidence cutoff Whether systemic senescent-cell targeting can be selective and safe in people without disrupting protective senescence, tissue repair, tumor suppression, or vulnerable vascular-cell populations.
Emergency instructions
This profile does not contain verified, product-specific emergency instructions.
Evidence boundary
Relay does not infer emergency guidance from study discontinuations, mechanism, or incomplete adverse-event reporting.
Dosing references
Dosing & preparation
Each table labels its source and applies only to the named route, product, or study. An online example or community report is not an approved dose.
Route: Route unverified · No exact human administration route established in this review
Evidence gap · Route unverified
No verified administered-human regimen
Cell and animal senescence experiments do not establish a human dosing schedule or safe exposure range.
What would fill this gap: A verified human protocol for the exact FOXO4-DRI peptide.
Dosing review checked Oct 20, 2026. Additional sources are available below.
Formulation & handling · Route unverified
No route-specific preparation instructions were verified. A different route or product does not supply them.
Starting dose, maintenance, and trial targets explained
Starting dose: the amount used at the beginning of the named label schedule or trial.
Maintenance: the ongoing amount described by that product label.
Trial target: the amount assigned to a study group. Different groups may stop increasing at different targets.
Other source records, populations, and limits · all routes
Preclinical evidence only
FOXO4-DRI foundational cell-and-mouse study material
Amount in this source
A complete human regimen was not verified in this source record. See the dosing status above.
Frequency
Defined by the model-specific preclinical protocols
Route
Laboratory cell exposure and animal administration
Duration
Model-specific short treatment periods
Population, study design, and limitations
Foundational research investigated FOXO4-DRI in senescence-enriched human fibroblasts outside the body and in progeroid or naturally aged mouse models.
Population: Laboratory cell models and mice
Design: Mechanistic experiments in senescent human fibroblasts followed by treatment in progeroid and naturally aged mouse models
No verified study administered FOXO4-DRI to human participants.
Cell selectivity and mouse tissue signals cannot establish human anti-aging benefit or resolve repair, vascular, immune, and tumor-suppression risks.
FOXO4-DRI is a cell-penetrating D-retro-inverso peptide derived from a FOXO4 interaction region. Foundational experiments reported competition with FOXO4 for p53 binding, nuclear redistribution of active p53, and preferential apoptosis in selected senescent fibroblast models, followed by improvements in several mouse tissue-homeostasis measures. Later NMR and biochemical work characterized binding to the intrinsically disordered p53 transactivation domain and the effect of p53 phosphorylation. Additional studies examined expanded human chondrocytes, keloid tissue, pulmonary fibrosis, vascular aging, and aged-mouse spermatogenesis. The evidence remains model dependent, and rodent pulmonary-hypertension work found that senescent-cell clearance, including FOXO4-DRI exposure, could worsen pulmonary vascular outcomes.
Why this matters
A plausible mechanism can explain why a study was attempted. It does not prove that the compound improves a human outcome.
Route studiedLaboratory cell exposure and animal administration
Schedules studiedDefined by the model-specific preclinical protocols; Model-specific short treatment periods
Amounts studiedWithheld: this record provides research context without a transferable amountWhy this matters
These are exposures used in cited research for a specific route and population—not an instruction for an individual.
Half-lifeNot established for this exact editorial recordWhy this matters
Half-life describes how long it takes the measured amount in the body to fall by half. It is not a dosing recommendation.
Route evidenceFoundational research investigated FOXO4-DRI in senescence-enriched human fibroblasts outside the body and in progeroid or naturally aged mouse models.Why this matters
Evidence can change by administration method. Findings from one route should not automatically be applied to another.
Evidence boundary: No verified study administered FOXO4-DRI to human participants. Cell selectivity and mouse tissue signals cannot establish human anti-aging benefit or resolve repair, vascular, immune, and tumor-suppression risks. Amounts shown describe cited research exposure—not a dosage recommendation.
Studies
Study-by-study record
Study arms are reported for transparency. They describe what researchers did in a defined record and do not transfer across identities, routes, formulations, or populations.
Why this matters
A later trial phase can ask a more mature question, but it does not guarantee a positive result, regulatory approval, or relevance outside the studied population.
Animal studyPeer reviewed
FOXO4-DRI regulates endothelial cell senescence via the P53 signaling pathway
Senescent endothelial-cell experiments plus naturally aged and induced-aging mouse models
Endothelial cells and mice
Outcomes measured
Aortic aging markers
Vascular function
p53 signaling
Apoptosis
What was reported
FOXO4-DRI altered FOXO4-p53 signaling, promoted apoptosis in senescent endothelial-cell models, and improved selected vascular-aging measures in mice.
Study administration and important limits
Study administration: FOXO4-DRI injection or control in preclinical protocols
Limitations: The work remains preclinical and does not resolve the contrasting pulmonary-vascular findings or establish cardiovascular safety in humans.
Mechanistic rationalePeer reviewed
The disordered p53 transactivation domain is the target of FOXO4 and the senolytic compound FOXO4-DRI
NMR structural modeling, molecular dynamics, and biochemical binding assays
Purified FOXO4 and p53 domains
Outcomes measured
Binding interfaces
Conformational behavior
Effect of p53 phosphorylation
What was reported
The study characterized FOXO4-DRI binding to the disordered p53 transactivation domain and showed that p53 phosphorylation can increase binding affinity.
Study administration and important limits
Study administration: FOXO4-DRI, FOXO4 domains, and phosphorylated or unmodified p53 domains
Limitations: Structural and binding data clarify a proposed mechanism but cannot establish cellular selectivity, whole-body safety, or therapeutic benefit.
Laboratory studyPeer reviewed
FOXO4-DRI induces keloid senescent fibroblast apoptosis by promoting nuclear exclusion of upregulated p53-serine 15 phosphorylation
Single-cell analysis, senescent-fibroblast experiments, and ex-vivo human keloid organ cultures
Human keloid tissue and fibroblasts studied outside the body
Outcomes measured
p53 localization
Cell-cycle arrest
Apoptosis
Senescence markers
What was reported
FOXO4-DRI promoted apoptosis in senescence-enriched keloid fibroblast models and altered p53 localization in cultured human tissue.
Study administration and important limits
Study administration: FOXO4-DRI under laboratory conditions
Limitations: Ex-vivo tissue and cell findings do not establish keloid prevention, recurrence reduction, wound-healing safety, or clinical treatment benefit.
Animal studyPeer reviewed
FOXO4-DRI improves spermatogenesis in aged mice through reducing senescence-associated secretory phenotype secretion from Leydig cells
Activated-fibroblast experiments and bleomycin-induced pulmonary fibrosis in mice
Laboratory fibroblasts and mice
Outcomes measured
Extracellular-matrix proteins
Collagen deposition
Lung histopathology
What was reported
FOXO4-DRI reduced selected extracellular-matrix measures in fibroblasts and was associated with less fibrosis and collagen deposition in the mouse model.
Study administration and important limits
Study administration: FOXO4-DRI under laboratory and mouse treatment protocols
Limitations: Bleomycin-induced fibrosis is an experimental model. The findings do not establish safety or benefit in people with pulmonary fibrosis.
Animal studyPeer reviewed
Eliminating Senescent Cells Can Promote Pulmonary Hypertension Development and Progression
DurationModel-specific acute and repeated exposures
Design and population
Senescent-cell clearance using genetic and pharmacologic approaches across multiple rodent pulmonary-hypertension models
Mice and rats with experimental pulmonary vascular disease
Outcomes measured
Pulmonary hemodynamics
Right-ventricular hypertrophy
Vascular remodeling
Pulmonary endothelial-cell survival
What was reported
In selected models, senescent-cell elimination, including FOXO4-DRI exposure, was associated with endothelial-cell loss and worse pulmonary-hypertension measures.
Study administration and important limits
Study administration: FOXO4-DRI, ABT263, genetic senescent-cell clearance, or controls
Limitations: The study does not determine human risk or isolate every FOXO4-DRI-specific effect, but it demonstrates that removing senescent cells can be harmful in some disease contexts.
Laboratory studyPeer reviewed
Senolytic Peptide FOXO4-DRI Selectively Removes Senescent Cells From in vitro Expanded Human Chondrocytes
In-vitro comparison of minimally and extensively expanded human chondrocytes
Chondrocytes isolated from healthy human donors
Outcomes measured
Cell survival
Senescence markers
Cartilage-forming potential
What was reported
FOXO4-DRI removed a larger fraction of extensively expanded, senescence-enriched chondrocytes than minimally expanded controls and altered subsequent cartilage-related laboratory measures.
Study administration and important limits
Study administration: FOXO4-DRI treatment during in-vitro cell expansion
Limitations: These cells were treated outside the body. The study does not establish joint, cartilage, osteoarthritis, or implantation outcomes in patients.
Animal studyPeer reviewed
Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging
Mechanistic experiments in senescent human fibroblasts followed by treatment in progeroid and naturally aged mouse models
Laboratory cell models and mice
Outcomes measured
Senescent-cell viability and selectivity
p53 localization and apoptosis
Senescence markers
Renal and tissue-homeostasis measures in mice
What was reported
FOXO4-DRI competed with FOXO4 for p53 binding, preferentially reduced viability in selected senescent fibroblast models, and improved several tissue-homeostasis measures in mouse aging models.
Study administration and important limits
Study administration: FOXO4-DRI or control under laboratory and animal research protocols
Limitations: This foundational work combined cell and mouse models. It did not test safety, pharmacokinetics, longevity, or clinical outcomes in humans, and selectivity may vary across senescent-cell types.
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