Is Thymalin legal in the United States?

A peptide extract from calf thymus, used in the Soviet Union and Russia since the 1980s. There is a large Russian medical literature on it. One study followed 266 older people for 6 to 8 years and reported about half as many deaths. A COVID study had 92 patients, and everyone knew who got what. Nobody outside that tradition has repeated any of it.

Thymalin is a mix of small proteins taken from calf thymus. Vladimir Khavinson's group made it alongside Epithalamin and put it into hospital use to correct the immune system.

How it works: Thymalin gives the body a mix of thymus signalling peptides. The idea is to make up for the thymus shrinking with age.

Approval history: Not FDA-approved. It was not one of the seven peptides the FDA's Pharmacy Compounding Advisory Committee looked at in July 2026

Approves prescription drugs, each for a named use. It also acts against unapproved products, including peptides sold online. Compounding pharmacies, which mix drugs to order, may make some compounds with a prescription. That only applies when the FDA puts the compound in a category of bulk ingredients it allows.

The legal category above is how The Longevity Archive reads U.S. Food and Drug Administration listings for Thymalin on the reviewed date. It is not a legal opinion. Rules change. Bringing a compound into the country, prescribing it and owning it can each be treated differently. Check with the agency before you act on anything here.

Check FDA directly

Whether Thymalin is banned in sport is set by the World Anti-Doping Code and by military rules, not by its legal status in the United States. Before you compete or get tested, look up Thymalin by name on the Prohibited List, or look up a named product in Global DRO. Under the World Anti-Doping Code, category S0 bans, at all times, any drug-like substance that meets two tests. No other section of the List covers it. And no government health regulator anywhere has a current approval for it as a treatment in people. Many substances that are approved somewhere are banned by name in another section. So approval does not mean a substance is allowed in sport.

• WADA Prohibited List
• Global DRO (check a named product)
• USADA (US athletes)
• Operation Supplement Safety (US service members)

The rules you compete or serve under decide this, not this page.