Foxo4-DRI vs MOTS-c

D-retro-inverso peptide that disrupts Foxo4/p53 interaction in senescent cells; restores p53-mediated apoptosis selectively in senescent cells; clears cellular "zombie cells"

FOXO4-DRI is a synthetic D-amino acid retro-inverso (DRI) peptide that disrupts the interaction between the FOXO4 transcription factor and p53 in senescent cells, triggering apoptosis selectively in cells with an activated senescent secretory phenotype (SASP) while sparing non-senescent cells in which this interaction is not tonically antiapoptotic. In senescent cells, overexpressed FOXO4 sequesters p53 in the nucleus and prevents it from initiating apoptosis, enabling the persistence of metabolically active senescent cells that secrete pro-inflammatory SASP cytokines; FOXO4-DRI competitively disrupts this FOXO4-p53 interaction, freeing p53 to activate its apoptotic transcriptional program specifically in cells where the FOXO4 sequestration is functionally relevant. The foundational study published in Cell demonstrated that FOXO4-DRI selectively induced apoptosis in senescent cells in vivo in mice, restoring tissue homeostasis in both chemotherapy-induced and naturally aged animals; subsequent molecular modeling work has characterized the FOXO4-TP53 interaction interface to guide further senolytic peptide design, though published evidence in humans is absent and the preclinical literature remains limited. FOXO4-DRI is a research compound with no regulatory approval in any jurisdiction; it has been studied only in preclinical animal models, and no human pharmacokinetic, safety, or clinical efficacy data has been established.

Mitochondria-derived peptide that translocates to nucleus under stress; activates AMPK pathway, regulates AICAR and folate-methionine cycle

MOTS-c (mitochondrial ORF of the 12S rRNA type-c) is a 16-amino-acid mitochondrial-derived peptide (MDP) encoded within the 12S ribosomal RNA gene of the mitochondrial genome, secreted from mitochondria into the cytoplasm and circulation in response to metabolic stress and exercise, where it functions as a hormonal signal regulating nuclear gene expression to promote metabolic homeostasis and insulin sensitivity. MOTS-c translocates from mitochondria to the nucleus under metabolic stress conditions, where it activates AMPK-dependent pathways that increase glucose uptake in skeletal muscle and adipose tissue, reduce lipid accumulation, and modulate one-carbon metabolism through the AICAR-AMPK-folate cycle — effects that parallel some metabolic actions of physical exercise and metformin. Foundational research published in Cell Metabolism characterized MOTS-c as a mitochondrially encoded metabolic hormone that promotes metabolic homeostasis, reduces obesity, and improves insulin resistance in preclinical models, and subsequent work has analyzed its broad metabolic regulatory role and clinical potential as an insulin-sensitizing agent. MOTS-c is a research compound with no regulatory approval in any jurisdiction; while circulating MOTS-c levels in humans have been characterized and decline with age, no clinical trials have established safety or efficacy for exogenous MOTS-c administration. MOTS-c dosage protocol: No human clinical trial has established a reference dosing protocol for exogenous MOTS-c administration. Animal research protocols examining MOTS-c metabolic effects have used subcutaneous injection as the primary delivery route, with doses determined by body weight in rodent models. Human circulating MOTS-c levels have been measured in exercise and aging studies — endogenous levels decline with age and rise transiently with aerobic exercise — but these observations do not establish a target dose for supplemental administration. Research interest focuses on MOTS-c as a potential exercise mimetic and insulin sensitizer, with investigation of dosing frequency and timing relative to metabolic challenge or fasted states. MOTS-c is a research compound; there are no approved human dosing guidelines for any indication.