TA1 · Thymalfasin · Zadaxin
Immune modulator — infection resistance and anti-cancer.
FDA
Compounding Allowed
WADA
Not Listed
HALF-LIFE
~2 hours
ROUTE
SubQ injection
SCHEDULE
2× weekly
In Plain English
Immune modulator — infection resistance and anti-cancer.
Status & Legality
NATTY?
No Test ExistsNo established test exists for this compound.
FDA
Compounding AllowedFor research purposes only. Not FDA approved.
WADA
Not ListedNot currently on WADA prohibited list.
COMPOUNDING
Not from pharmaciesNot available from licensed compounding pharmacies.
PRESCRIBED
Not prescribedNot prescribed in conventional medicine.
ROUTE
SubQ injectionAdministration via subq injection.
Immune enhancement
Antiviral activity
Cancer adjunct therapy
Hepatitis
Thymosin Alpha-1 (TA1) is the most potent immune-modulating peptide currently available. Approved in 37 countries for hepatitis B and C, it modulates T-cell maturation, enhances NK cell activity, and has shown benefit in cancer immunotherapy. It's used by longevity practitioners for immune optimization and during immune challenges.
Injection site reactions
Flu-like symptoms at start (immune activation)
Generally very well tolerated
Storing improperly — TA1 is heat-sensitive; refrigerate before use and do not leave reconstituted solution at room temperature
Using 0.9 mg when 1.6 mg (the clinically validated dose in 37-country approvals) is available and warranted
Expecting results within days for chronic immune conditions — TA1 builds and restores immune function over weeks of consistent use
Immunosuppressants — directly antagonistic; avoid combination in organ transplant patients on maintenance suppression
Interferon — additive antiviral effects; used in combination clinically for hepatitis B and C
Corticosteroids — may blunt TA1's immune-enhancing effects; avoid combining during active immune restoration protocols
Thymosin Alpha-1 is the most clinically validated immune peptide available — approved in 37 countries for hepatitis B and C with extensive human safety data. At 1.6 mg 2×/week, it reliably improves immune surveillance. For acute illness, daily dosing for 1–2 weeks is the accelerated protocol most longevity practitioners use.
Stats
Sources & Studies
Goldstein AL. et al., Expert Opin Biol Ther, 2009