Peptide

Thymosin Alpha-1

28-amino-acid peptide produced in the thymus; stimulates T-cell maturation and reverses signs of immunosenescence. Approved in more than 35 countries (not in the US) for hepatitis B/C, sepsis, and oncology.

Regulatory status

Not approved

FDA (U.S.): Not approved. It only has orphan drug designations (e.g., melanoma, 2006), which are not authorizations. The FDA considered its safety data insufficient for compounding (proposal withdrawn).

EMA (EU): No centralized authorization (orphan designation for hepatocellular carcinoma in 2002, which is not an authorization). Authorized nationally in Italy to boost the response to the influenza vaccine. Outside the EU/U.S. it is approved in more than 35 countries (mainly in Asia) for hepatitis B and C.

How to take it

1.6 mg subcutaneously twice a week is the most studied regimen. Medical decision.

Safety

Good safety profile in trials. Local reactions at the injection site. Caution in active autoimmunity (its immunomodulatory effect may be bidirectional).

Effect by goal · level of evidence

Hepatitis B and C

improves Very high meta-analysis (AAA)

Clinical approval

Approved for hepatitis B/C in more than 35 countries; improves sustained virological response when combined with antivirals in meta-analyses.

View the study (meta-analysis) →

Sepsis

improves Moderate clinical trials (AA)

↓ Mortality in sepsis

Reduces mortality in severe sepsis according to trials in Asia; used as an adjuvant in the ICU in some countries.

View the study (RCT) →

Immunosenescence

improves Moderate small trials (A)

Improves immune function

Reverses markers of immune aging in older adults, but does NOT structurally regenerate the thymus.

View the study (RCT) →

Information, not medical advice. Scientific evidence reflects the quality of the studies.