Thymosin Alpha-1
Thymic peptide approved in 40+ countries for hepatitis B/C and as an immune adjuvant in oncology. Marketed as Zadaxin. The most extensively studied immune peptide in this database, with a substantial international clinical trial base.
Thymosin Alpha-1 (TA1) is a 28-amino acid peptide originally isolated from the thymus gland. It is commercially produced as Zadaxin (SciClone Pharmaceuticals) and has been approved in over 40 countries and territories, primarily for hepatitis B and C treatment and as an immune adjuvant in oncology.
TA1 modulates immune function through multiple mechanisms: promoting T-lymphocyte maturation, activating natural killer cells, enhancing dendritic cell function, and normalizing the cytokine environment. Unlike broad immunostimulants, TA1 is believed to modulate immune function toward appropriate regulation — making it potentially relevant for both immune-deficient and autoimmune contexts.
In US physician practice, TA1 is used for autoimmune conditions, recurrent infections, chronic immune dysregulation, and general immune support. The international clinical data provides the most robust evidence base of any peptide in the immune category — with a well-established safety profile from clinical use across multiple indications.
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Thymosin Alpha-1 has an extensive international safety database — generally well-tolerated, with injection site reactions as the primary adverse effect. Not FDA-approved for any US indication. Not currently WADA-prohibited (verify current list). All information for educational reference only.