How does epitalon affect circadian rhythm and melatonin?

Epitalon is a synthetic tetrapeptide derived from pineal gland extracts that has been studied for its effects on melatonin production and circadian gene expression. Research conducted primarily in Russia suggests epitalon may restore age-related declines in nighttime melatonin levels and normalize circadian rhythm amplitude. Studies in aged primates showed increased basal night melatonin levels following epitalon administration, though independent replication of these findings outside Russia remains limited.