C129H215N33O55 · 3108.3 g/mol · PubChem CID 16130571 ↗
Thymosin α-1
also known as Tα-1, Zadaxin, Thymalfasin, thymosin alpha 1
Synthetic 28-amino-acid peptide identical to a peptide isolated from calf thymus. Approved as Zadaxin (thymalfasin) in 35+ countries for chronic hepatitis B + C, immune restoration after chemotherapy, and investigated as an HIV/HBV vaccine adjuvant. Not FDA-approved in the US, but extensive Phase 3 data exists.
- Class
- Synthetic 28-AA thymic peptide
- Evidence level
- Phase 3 clinical
- Regulatory status
- Not FDA-approved (US) — research use only
At a glance
SQ · 2× weekly · 6+ months for chronic indications
Primary target — Toll-like receptor 9 (TLR9) + T-cell maturation pathway [camerini-2001-talpha1].
Pathway — TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturation [iyer-2007-talpha1].
Downstream effect — Restored T-cell function, improved viral clearance, anti-tumour adjuvant effects [iyer-2007-talpha1].
Origin — Synthetic 28-AA peptide identical to natural Tα-1 isolated from thymus extract [camerini-2001-talpha1].
| Parameter | Value |
|---|---|
| Standard dose (HBV/HCV) | 1.6 mg SQ 2× weekly × 6–12 months [iyer-2007-talpha1] |
| Frequency | 2× weekly (Mon/Thu typical) |
| Lower / starter dose | 0.8 mg per injection |
| Evidence basis | Phase 3 + approved (35+ countries as Zadaxin) [iyer-2007-talpha1] |
| Duration | 6–12 months for chronic indications |
| Reconstitution | Sterile water for injection per vial label |
| Timing | No specific time |
| Half-life | ~2 hours plasma; tissue effect days |
Reconstitution
A pure mass-to-volume utility. Enter what you have in the vial; the atlas computes the volume per dose. No prescription information.
- — Pregnancy / breastfeeding
- — Hypersensitivity to peptide
- — Concurrent immunosuppressant therapy (transplant patients)
- — Active autoimmune disease
- — Severe immunocompromised state without supervision
- 01Reconstitution
Add 1 mL sterile water per 1.6 mg vial → 1.6 mg/mL.
- 02Injection site
SQ — abdomen, thigh, or upper arm. Rotate sites.
- 03Timing
2× weekly, e.g. Monday + Thursday.
- 04Storage
Lyophilised: refrigerate. Reconstituted: refrigerate, use within 24 h.
- 05Needle
27–31G, 4–8 mm insulin syringe.
Frequently asked
How does Thymosin α-1 work?
Thymosin α-1 acts on Toll-like receptor 9 (TLR9) + T-cell maturation pathway, signalling via TLR9 activation → ↑ IFN-α + IL-2 + IFN-γ → enhanced T-cell function + dendritic cell maturation. [camerini-2001-talpha1][iyer-2007-talpha1]
Is Thymosin α-1 FDA-approved?
Thymosin α-1 is not FDA-approved in the United States and is handled as a research compound (research use only). Regulatory status may differ in other jurisdictions.
Sources
of 39 rendered claims carry a resolvable citation.
- [camerini-2001-talpha1]Camerini 2001 — Thymosin alpha-1: a clinical update
Curr Opin Investig Drugs, 2001
Thymosin α-1 immune modulation review. - [iyer-2007-talpha1]Iyer 2007 — Zadaxin (Thymalfasin) for chronic hepatitis B and C
Curr Pharm Des, 2007
Thymosin α-1 (Zadaxin) clinical review for hepatitis.