Thymosin Alpha-1: What It Is and Its U.S. Regulatory Status

What is thymosin alpha-1?

Thymosin alpha-1 is a peptide made of 28 amino acids. It was first isolated from thymus tissue, the small organ in the chest where T cells, a type of white blood cell, mature. The synthetic form of the peptide has the generic name thymalfasin.

Thymosin alpha-1 is one of several peptides once grouped together as “thymosins.” Despite the similar names, it is not structurally related to thymosin beta-4, the protein that TB-500 is based on.

Research and approval outside the U.S.

Thymalfasin has been studied in clinical trials, including trials in people with chronic hepatitis B. It is approved in a number of countries outside the United States under the brand name Zadaxin.

Approval in other countries does not carry over to the United States. Each drug must go through its own FDA review before it can be marketed to U.S. patients.

U.S. regulatory status

Current status: Not FDA-approved.

This means the FDA has not approved thymosin alpha-1 as safe and effective for any medical use. No product containing it is an approved medicine in the United States.

This also means there is no FDA-approved U.S. product that a pharmacy can dispense under the Zadaxin name.

Why Peptide Labs does not sell thymosin alpha-1

Peptide Labs does not sell this compound. This page is general information, not medical advice. We do not supply, prepare or distribute thymosin alpha-1 in any form, and nothing on this page should be read as an offer.

If you have questions about thymosin alpha-1 or a related health concern, talk to a licensed healthcare provider who knows your medical history.

Related reading

See the full list of compound profiles in the Peptide Guide.