Thymosin alpha-1: what the studies show

Identity and study population

Thymosin alpha-1 is also called thymalfasin and is associated with the Zadaxin brand. It is distinct from thymosin beta-4 and its fragments. These peptides' results cannot be pooled.

The TESTS trial enrolled 1,106 adults with sepsis at 22 centers in China. Its modified intention-to-treat analysis included 1,089 participants. The trial studied treatment during serious illness. It did not test prevention in healthy adults.

The corrected TESTS results

Researchers compared subcutaneous thymosin alpha-1 with placebo every 12 hours for seven days, with early stopping for specified hospital events. This trial schedule does not establish a validated wellness regimen.

Mortality at 28 days was 23.4% with thymosin alpha-1 and 24.1% with placebo. The corrected hazard ratio was 0.97, with a 95% confidence interval of 0.76 to 1.24. The trial found no clear mortality benefit.

Who might benefit

The immune mechanism does not establish which patients benefit clinically. No FDA-approved product was identified. FDA flags safety gaps and inadequate characterization of compounded preparations. Study results also cannot be transferred to thymosin beta-4 products.