Epithalon

Epithalon is alanyl-glutamyl-aspartyl-glycine, a four-residue peptide identified as the active fragment of epithalamin, a pineal gland extract characterised in Russian gerontology research from the 1980s onward. The published work spans telomerase reverse transcriptase expression in somatic cell culture, melatonin rhythm regulation and chromatin structure, with a distinctive proposed mechanism involving direct peptide-DNA interaction at specific promoter sequences rather than conventional receptor binding.

The sequence is short and strongly acidic — three of the four residues carry or neighbour carboxylate groups — which makes solutions acidic and makes the peptide adsorb to anion exchange surfaces. It is inexpensive to synthesise, which unfortunately means it is also inexpensive to fake, and a tetrapeptide is small enough that casual analysis is easily satisfied. We run full identity confirmation on it regardless.