FTS · Serum Thymic Factor · Glu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH
Thymic hormone — T-cell maturation and immune aging.
FDA
Research Only
WADA
Not Listed
HALF-LIFE
Unknown
ROUTE
SubQ injection
SCHEDULE
Daily or 3× weekly
In Plain English
Thymic hormone — T-cell maturation and immune aging.
Status & Legality
NATTY?
No Test ExistsNo established test exists for this compound.
FDA
Research OnlyFor 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.
T-cell maturation
Immune aging
Thymus support
Anti-inflammatory
Thymulin is the primary zinc-dependent thymic hormone responsible for T-cell differentiation and maturation. Levels decline sharply after age 60, paralleling immune senescence. Research shows supplementation restores NK cell activity, reduces pro-inflammatory cytokines, and improves immune surveillance in aging models.
Mild injection site reactions
Transient immune activation symptoms
Generally well tolerated
Not ensuring adequate zinc status before starting — Thymulin is zinc-dependent; deficiency renders it effectively inactive
Using oral preparations instead of SubQ injection — Thymulin is not bioavailable orally
Skipping zinc co-supplementation — zinc is structurally required for thymulin activity; always supplement 25 mg zinc alongside
Zinc supplements — required cofactor; optimize zinc status to baseline (25–50 mg/day) before and during Thymulin use
Immunosuppressants — direct antagonism; avoid in transplant patients
Corticosteroids — reduce thymic output and may blunt Thymulin's T-cell maturation effects
Thymulin's zinc-dependency is what most users miss — and it's not optional. Before starting, test zinc levels and correct any deficiency. The triple immune protocol (Thymulin + Thymosin Alpha-1 + Thymalin) addresses thymic function from three distinct angles and represents the most comprehensive immune restoration approach in the index.
Stats
Sources & Studies
Dardenne M., Mol Immunol, 2006