Thymosin Alpha-1

How it works

From the thymus, where T cells mature: a peptide meant to boost them, given for hepatitis B and weak flu-shot responses.

What it's made of

28 amino acids, the first one acetylated, isolated in 1977 from an extract of calf thymus. They are the start of a larger protein, prothymosin alpha (111). The drug is synthetic and identical.

What it's for

Prescribed for

In Italy, to improve the response to the flu vaccine in immunocompromised people. In other countries, chronic hepatitis B. In the US and Spain, nothing.

Sold as

Boosts your defenses: more T cells and a better response to viruses and vaccines.