Thymosin Alpha-1 (Tα1) is a 28-amino-acid peptide originally isolated from thymic tissue, known for its role in the development and modulation of the adaptive immune system. It enhances T-cell maturation, dendritic cell activation, and the production of cytokines, making it a key focus in research related to immune function and host defense mechanisms.

Tα1 has been extensively studied for its antiviral, antitumor, and immunoregulatory effects, particularly in conditions involving immune suppression, chronic infections (such as hepatitis B and C), and cancer-related immune dysfunction. It acts by boosting the activity of natural killer (NK) cells, CD4+ helper T cells, and enhancing interferon responses, leading to improved pathogen clearance and immune balance.

Due to its favorable safety profile and multifaceted immunological impact, Thymosin Alpha-1 is frequently used in clinical immunology and infectious disease research, as well as in studies exploring immune recovery during chemotherapy, sepsis, and other immunocompromised states.