Peptide · Immune support
Thymosin Alpha-1 is a synthetic peptide studied for immune modulation. Approved in some countries; not FDA-approved in the U.S.
Thymosin Alpha-1 is a synthetic peptide studied for immune modulation. Approved in some countries; not FDA-approved in the U.S.
Thymosin alpha-1 is a 28-amino-acid peptide naturally produced by the thymus gland. It modulates T-cell maturation and function, enhances Th1-mediated immune responses, and has antiviral and immune-modulatory effects. Synthetic thymosin alpha-1 (Zadaxin) is approved in over 30 countries (not the US) for hepatitis B, hepatitis C, and as an immune adjuvant.
Approved in some countries (e.g., Italy, China). Not FDA-approved in the U.S.
Compounded in the U.S. — not FDA-approved.
Common protocols: 1.6 mg subcutaneous twice weekly for chronic immune support, or 1.6 mg subcutaneous daily for acute immune protocols. Cycle length varies from 4 weeks to indefinite use depending on indication.
Dosing in research and clinical-use contexts varies. Specific protocols should always be set by a prescribing clinician, not by patient-direct sources.
Generally well-tolerated, with a strong safety record from the international approved-product use. Reported side effects: injection-site reactions, mild flu-like symptoms early in treatment (consistent with immune activation). Patients on immunosuppressive therapy should not use without their oncologist's or immunologist's input.
Often used standalone for immune support. Can be combined with thymosin beta-4 for combined immune + tissue-repair effects.
Most peptides discussed on this page are compounded products requiring a prescription from a licensed clinician. Reputable telehealth peptide programs include physician-led oversight, accredited compounding pharmacies, and clear regulatory framing. For weight-management GLP-1 programs, see our provider reviews.
Thymosin Alpha-1 is a synthetic peptide studied for immune modulation. Approved in some countries; not FDA-approved in the U.S.
Compounded in the U.S. — not FDA-approved.
Uses include: Immune support (research), Adjunct in chronic infections (research). This is research and clinical-use context, not a recommendation. Always work with a licensed clinician.
Approved in some countries (e.g., Italy, China). Not FDA-approved in the U.S.
Reported dosing: 1.6 mg subcutaneous twice weekly. Actual dosing should always be determined by your prescribing clinician, not by online sources.
Zadaxin is approved in over 30 countries but the manufacturer has not pursued US approval. Available through US compounding pharmacies.
Yes. Thymosin alpha-1 is for immune function. Thymosin beta-4 (TB-500 is a fragment of it) is for tissue repair. They are different peptides with different mechanisms.