Thymosin Alpha-1 (Tα1) is a 28-amino-acid peptide fragment of prothymosin alpha, naturally produced by the thymus gland, that modulates immune function. It is approved in more than 30 countries as Zadaxin and is studied for T-cell maturation, natural killer (NK) cell activity, and balanced immune modulation.
Standard Research Dosage
The most commonly referenced protocol is 1.6 mg administered subcutaneously twice per week — the same dose used in the approved Zadaxin formulation. Some immune-support research protocols front-load with daily 1.6 mg dosing for the first 1–2 weeks before tapering to twice weekly.
Administration and Timing
Thymosin Alpha-1 is reconstituted with bacteriostatic water and injected subcutaneously, typically into abdominal fat. It can be dosed at any time of day; the key variable is spacing — roughly every 3–4 days for sustained immune modulation rather than same-day clustering.
Mechanism of Action
Tα1 promotes the maturation and differentiation of T-lymphocytes, enhances NK-cell cytotoxicity, and modulates cytokine production through Toll-like receptor signaling (notably TLR9 and TLR2). The net effect studied in research is a shift toward a balanced Th1 immune response.
Cycle Length
Protocols vary by application — from 2–4 week courses for acute immune-support research to extended multi-month protocols in chronic immune studies. In its approved clinical uses, course length is indication-specific and physician-directed.