Thymosin alpha-1

Thymosin alpha-1 is a 28-amino-acid peptide identical to a fragment of prothymosin alpha, a protein found in many cells but first isolated from the thymus. It is registered as a prescription medicine in a number of countries (for example as Zadaxin in Italy and parts of Asia and Latin America) but has never been approved by the FDA or EMA.

1. 1

   Acts on immune cells rather than on a single receptor — it is described as an immune response modifier.

2. 2

   Enhances T-cell maturation and function, including the balance of helper T-cell responses.

3. 3

   Stimulates production of cytokines such as interferon and interleukins in laboratory studies.

4. 4

   Increases activity of natural killer cells in some models.

5. 5

   Its effects are immunomodulatory rather than directly antiviral or antibacterial.

• Improved virological response rates in some hepatitis trials when combined with interferon
• Changes in T-cell and cytokine markers consistent with immune activation
• Mixed results in sepsis; some trials showed mortality benefit, others did not
• Trial quality has varied considerably, which limits confidence

1. 01Thymosin alpha 1 clinical trials overview — PubMed literature search
2. 02Thymosin alpha 1 in sepsis — PubMed literature search
3. 03Zadaxin (thymosin alpha 1) product information — Italian Medicines Agency (AIFA)

References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.