What the research shows

The double-blind TESTS trial randomized adults with sepsis to thymosin alpha-1 or placebo. Among the 1,089 people analyzed, 28-day mortality was 23.4% with thymosin alpha-1 and 24.1% with placebo. The difference was statistically inconclusive. TESTS randomized sepsis trial.

A U.S. FDA pharmacy compounding advisory meeting reviewed the 28-residue structure and the importance of its N-terminal acetyl group when characterizing the substance. FDA compounding advisory material.

Documented formats

The sepsis trial documents a freeze-dried preparation of thymosin alpha-1 and a matched placebo.

Testing and purity

Look for the complete 28-residue sequence and N-terminal acetylation in the identity report. A reference to ‘thymosin’ alone could refer to a different peptide.

How to read a batch report

Questions about Thymosin Alpha-1

What was the main outcome in TESTS?

The investigators counted deaths from any cause within 28 days. This addresses a specific clinical question in adults with sepsis.

Are thymosin alpha-1 and TB-500 the same?

They have different sequences and origins. The TB-500 fragment characterized in analytical studies comes from thymosin beta-4.