A cellular housekeeping process in which cells digest and recycle their own damaged or unnecessary components—organelles, misfolded proteins, and other cellular debris. The term literally means “self-eating.” Autophagy is essential for cellular health: it clears toxic aggregates, provides building materials during nutrient scarcity, and helps cells adapt to stress.

Autophagy declines with age, and this decline is implicated in neurodegeneration, cancer, metabolic disease, and immune dysfunction. Several peptide compounds interact with autophagy pathways: MOTS-c activates AMPK (a key autophagy trigger), NAD+ precursors support the sirtuins that regulate autophagy, and Epithalon’s proposed longevity mechanisms include autophagy enhancement. Caloric restriction and fasting are the most well-established autophagy activators—peptide-mediated autophagy enhancement remains largely a preclinical finding.