Thymalin

Polypeptide complex extracted from calf thymus — immune-system restoration in aging and infection.

Thymalin is a natural extract of thymus tissue (rather than a single synthetic peptide), used in Russia for decades to restore immune function in older and chronically ill people. It's best known from the long-running Khavinson aging cohorts, where elderly subjects given periodic Thymalin courses showed better immune markers and, strikingly, lower mortality over years of follow-up. Think of it as a periodic "immune reset" run a couple of times a year — and one half of the classic Epitalon + Thymalin longevity pairing.