Thymosin Alpha-1

Description

Thymosin alpha-1 (Tα1) is a 28-amino-acid, N-terminally acetylated peptide derived from prothymosin alpha, first isolated from calf thymus tissue. Its synthetic drug form, thymalfasin, has been studied in hepatitis B, hepatitis C, sepsis and as a vaccine adjuvant, but it has never been approved by the U.S. FDA. FDA orphan-drug designations granted for thymalfasin are not approvals.

Research Context

Laboratory studies examine Tα1 in T-cell maturation, dendritic cell signalling and Toll-like receptor pathways. Clinical evidence is mixed. The multicentre TESTS trial in adults with sepsis, published in the BMJ in 2025, found no difference in 28-day all-cause mortality between thymalfasin and placebo. For a side-by-side look at the evidence, see our Thymosin Alpha 1 vs Thymalin comparison and the related Thymalin research peptide.

Specifications

• Sequence length: 28 amino acids, N-terminal acetylation
• Purity: ≥99% (HPLC)
• Form: lyophilized powder
• Storage: -20°C before reconstitution; 2-8°C after reconstitution
• Made in the USA

For research use only. This product is not for human or veterinary use, and is not a drug, food or cosmetic. It is not intended to diagnose, treat, cure or prevent any disease.