Family · longevity
FOXO4-DRI
FOXO4 D-Retro-Inverso peptide, FOXO4-p53 interfering peptide, ProxofimⓇ (research designation)
FOXO4-DRI is an experimental senolytic peptide engineered as a D-retro-inverso (DRI) analog: it uses D-amino acids assembled in reversed sequence, which approximates the side-chain topology of the natural L-peptide while resisting proteolysis and extending intracellular persistence. It is derived from the region of the transcription factor FOXO4 that binds p53. In senescent cells, FOXO4 sequesters p53 in the nucleus and blocks p53-driven apoptosis, helping these cells survive in a senescent-but-viable state. FOXO4-DRI competitively disrupts the FOXO4-p53 interaction, causing p53 nuclear exclusion and triggering cell-intrinsic (mitochondrial) apoptosis preferentially in senescent cells, whose survival depends on this interaction, while sparing most proliferating and quiescent cells. The intended net effect is selective clearance of senescent cells ('senolysis') to relieve senescence-associated tissue dysfunction.
Evidence is entirely preclinical. The foundational study (Baar et al., Cell 2017) reported that FOXO4-DRI selectively induced apoptosis in senescent cells and, in naturally aged and fast-aging mice, reduced senescent-cell burden, counteracted doxorubicin chemotoxicity, and improved fitness, fur density, and renal function. Subsequent cell-culture and mouse work (e.g., Le et al., eBioMedicine 2021) has refined FOXO4-p53-disrupting peptides and explored tumor and tissue models. No human clinical trials have been completed; there is no evidence of safety or efficacy in people, and FOXO4-DRI should be regarded as a highly experimental laboratory reagent, not a therapeutic.
- Preclinical senolytic research in senescence and aging mouse models
- In vitro elimination of senescent cells in cell culture
- Mechanistic research on the FOXO4-p53 apoptosis-regulation pathway
- Exploratory models of chemotoxicity and tissue-function decline
Educational overview only — no dosing instructions in the public hub.
Human safety is entirely unknown — there are no human trials, no established dose, and no characterized adverse-event profile. Interfering with p53 regulation raises theoretical concerns of off-target apoptosis in healthy tissue, immune and vascular effects, and unpredictable oncogenic consequences given p53's central role in tumor suppression. Preclinical reports themselves note narrow tolerability windows in animals. This is a research compound to be handled as a laboratory reagent, never a supplement; self-administration carries unquantified and potentially serious risk.
As a research-use-only material, FOXO4-DRI has no pharmaceutical quality assurance. Sequence and stereochemical identity are especially critical for D-retro-inverso peptides, where the correct D-amino acids and reversed sequence must be confirmed. A third-party certificate of analysis with purity (HPLC), quantification, and mass-spectrometry identity confirmation is the minimum verification, and even a clean CoA does not make the compound safe or suitable for human use.
Research-use-only; not approved for human use by any regulator (FDA, EMA, MHRA) anywhere. It is not a medicine, supplement, or authorized therapy, and legitimate use is confined to laboratory research.
Frequently asked questions
- What is FOXO4-DRI used for?
- Preclinical senolytic research in senescence and aging mouse models. In vitro elimination of senescent cells in cell culture. Mechanistic research on the FOXO4-p53 apoptosis-regulation pathway. Exploratory models of chemotoxicity and tissue-function decline. Evidence is entirely preclinical. The foundational study (Baar et al., Cell 2017) reported that FOXO4-DRI selectively induced apoptosis in senescent cells and, in naturally aged and fast-aging mice, reduced senescent-cell burden, counteracted doxorubicin chemotoxicity, and improved fitness, fur density, and renal function. Subsequent cell-culture and mouse work (e.g., Le et al., eBioMedicine 2021) has refined FOXO4-p53-disrupting peptides and explored tumor and tissue models. No human clinical trials have been completed; there is no evidence of safety or efficacy in people, and FOXO4-DRI should be regarded as a highly experimental laboratory reagent, not a therapeutic.
- Is FOXO4-DRI legal in Europe?
- Research-use-only; not approved for human use by any regulator (FDA, EMA, MHRA) anywhere. It is not a medicine, supplement, or authorized therapy, and legitimate use is confined to laboratory research.
- What are the risks and side effects of FOXO4-DRI?
- Human safety is entirely unknown — there are no human trials, no established dose, and no characterized adverse-event profile. Interfering with p53 regulation raises theoretical concerns of off-target apoptosis in healthy tissue, immune and vascular effects, and unpredictable oncogenic consequences given p53's central role in tumor suppression. Preclinical reports themselves note narrow tolerability windows in animals. This is a research compound to be handled as a laboratory reagent, never a supplement; self-administration carries unquantified and potentially serious risk.
- How is the quality of FOXO4-DRI assessed?
- As a research-use-only material, FOXO4-DRI has no pharmaceutical quality assurance. Sequence and stereochemical identity are especially critical for D-retro-inverso peptides, where the correct D-amino acids and reversed sequence must be confirmed. A third-party certificate of analysis with purity (HPLC), quantification, and mass-spectrometry identity confirmation is the minimum verification, and even a clean CoA does not make the compound safe or suitable for human use.