Thymosin Alpha-1 (Thymalfasin)

Lyochem primary owner

Overview

Thymosin Alpha-1 (Thymalfasin; marketed as Zadaxin) is a 28-residue, N-terminally acetylated immunomodulatory peptide, originally recovered from bovine thymus and now made synthetically. Mechanistically it drives T-cell maturation and function via TLR-9-dependent dendritic-cell activation and additionally modulates NK-cell and macrophage activity, the pharmacology that underpins both its antiviral and immune-restoration research interest. Regulatory status is unusual for a peptide of this size: it is an approved prescription biological in more than 35 jurisdictions, among them China, Italy, India, and several Southeast Asian markets, with indications spanning chronic hepatitis B, chronic hepatitis C in combination regimens, and use as a vaccine adjuvant. Lyochem supplies Thymosin Alpha-1 as a lyophilized reference standard at ≥99.0% HPLC purity. At 28 residues the chain is well within dependable SPPS range, and the N-terminal acetyl group is verified by ESI-MS as a +42 Da shift against the unacetylated peptide. Given its approved-drug status across many markets, we build extra depth into the applicable batch documentation, which can pair the HPLC chromatogram and mass spec with counter-ion and water-content figures and, on request, adds microbial limits plus endotoxin (LAL) testing. Fills of 5 mg and 10 mg. Lyochem furnishes the material strictly for research use only.

Applications & buyer fit

Specifications

CAS

62304-98-7

Sequence

SDAAVDTSSEITTKDLKEKKEVVEEAEN

Appearance

White to off-white lyophilized powder

Purity (HPLC)

≥ 99.0%

Strength

2 mg – 10 mg

Packaging

10 vials/box · base pack (multiples of 10)

Half-life

≈ 3 hours

MOQ

On request

Lead time

10–18 days

Storage

2–8°C, protect from light

Documentation available on request

• Lot-specific Certificate of Analysis (CoA)
• RP-HPLC chromatogram with peak integration
• ESI-MS identity confirmation (±0.5 Da)
• Sequence verification by LC-MS/MS
• Water content by Karl Fischer
• SDS / MSDS
• Bacterial endotoxin (LAL, USP <85>) — recommended for in vivo work
• Microbial limits (USP <61>/<62>) on request
• Low-bind plasticware notes for cationic AMPs

Independent analytical reports

Product- and strength-matched first-page previews are shown separately from the Batch COA. Contact sales with the report number for the complete high-resolution file.

Third-party testView report record →

Thymosin Alpha-1

10 mg · HPLC / MS

TA10-20260806S9397

Third-party testView report record →

Thymosin Alpha-1

5 mg · HPLC / MS

TA5-20260806S9397

Third-party testing in Tianjin

Independent HPLC and mass-spectrometry reports from Qorix , the professional, authoritative third-party analytical laboratory at tjqxgd.com, affiliated with the Tianjin International Joint Academy of Biomedicine.

Regulatory note

Across more than 35 jurisdictions — among them China, Italy, India, and several APAC markets — this is approved as a prescription biological, marketed as Zadaxin or as generic equivalents. As of this writing it is not approved in the US or EU, and sales are limited to qualified buyers who hold appropriate licensing in their jurisdiction.

Selected literature

1. Goldstein AL, Low TL, McAdoo M, McClure J, Thurman GB, Rossio J, Lai CY, Chang D, Wang SS, Harvey C, Ramel AH, Meienhofer J. Thymosin alpha1: isolation and sequence analysis of an immunologically active thymic polypeptide. Proc Natl Acad Sci U S A. 1977;74(2):725-729.
2. Romani L, Bistoni F, Montagnoli C, Gaziano R, Bozza S, Bonifazi P, Zelante T, Moretti S, Rasi G, Garaci E, Puccetti P. Thymosin alpha1: an endogenous regulator of inflammation, immunity, and tolerance. Ann N Y Acad Sci. 2007;1112:326-338.
3. Wu J, Zhou L, Liu J, Ma G, Kou Q, He Z, Chen J, Ou-Yang B, Chen M, Li Y, Wu X, Gu B, Chen L, Zou Z, Qiang X, Chen Y, Lin A, Zhang G, Guan X; Chinese Severe Sepsis Cooperation Group. The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial. Crit Care. 2013;17(1):R8.
4. Gu B, Zhou Y, Nie Y, Wang L, Liang L, Liao Z, Wen J, Guan X, Chen M, Wu J, Pei F. Efficacy of thymosin α1 for sepsis: a systematic review and meta-analysis of randomized controlled trials. Front Cell Infect Microbiol. 2025;15:1673959.
5. Liu F, Wang HM, Wang T, Zhang YM, Zhu X. The efficacy of thymosin α1 as immunomodulatory treatment for sepsis: a systematic review of randomized controlled trials. BMC Infect Dis. 2016;16:488.
6. Liu Y, Pang Y, Hu Z, Wu M, Wang C, Feng Z, Mao C, Tan Y, Liu Y, Chen L, Li M, Wang G, Yuan Z, Diao B, Wu Y, Chen Y. Thymosin alpha 1 (Tα1) reduces the mortality of severe COVID-19 by restoration of lymphocytopenia and reversion of exhausted T cells. Clin Infect Dis. 2020;71(16):2150-2157.

Frequently asked questions