Epithalon (also spelled Epitalon) is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) derived from the natural polypeptide epithalamin produced in the pineal gland. It has been studied primarily by Russian research groups, with published work exploring its effects on telomerase activation, DNA repair, melatonin synthesis, and antioxidant capacity in aged animal models. Some in-vitro studies have reported telomere elongation in human cell cultures. Epithalon has also been examined for effects on circadian rhythm regulation and neuroendocrine function. It remains an active area of aging biology research.