Thymosin alpha-1 (Tα1) is a 28-amino-acid peptide involved in immune-response regulation. Its synthetic form is called thymalfasin; ZADAXIN is one trade name. Findings in specific patient groups do not establish general immune-boosting or anti-aging benefits.
How do thymosin alpha-1, thymalfasin and ZADAXIN differ?
Thymosin alpha-1 names the peptide, thymalfasin names its synthetic form, and ZADAXIN identifies a branded medicine. ZADAXIN product information hosted by Indonesia’s medicines regulator describes chemically synthesized thymosin alpha-1. Substance identity and product identity should therefore be checked separately. BPOM Indonesia — ZADAXIN product information
Is it the same as thymosin beta-4 or TB-500?
No. Thymosin alpha-1 and thymosin beta-4 are different substances. A listing called TB-500 also needs its own label checked. Sharing part of a name does not make their evidence interchangeable.
What do human studies show?
TESTS, 2025: sepsis outcomes
This double-blind, placebo-controlled randomized trial enrolled 1,106 patients with sepsis at 22 Chinese centers. It did not show clear evidence that thymosin alpha-1 reduced mortality at 28 days. It did not test wellness use in healthy people. Wu et al., 2025 — TESTS randomized phase 3 sepsis trial
A correction was published on 30 May 2025. Both the main report and correction are linked so readers can consult the complete publication record. BMJ, 30 May 2025 — Correction to the TESTS trial
GATES, 2026: one component of cancer treatment
An open-label phase 2 study of 30 patients with gastric or gastroesophageal-junction cancer reported pathological responses after treatment involving several medicines, including thymalfasin. Without a randomized comparison isolating thymalfasin, the study cannot establish how much it contributed. It is not evidence for cancer prevention. Xu et al., 2026 — GATES prospective gastric cancer study
Is there a Thai registration record?
The Thai FDA database displays ZADAXIN, registration 1C 94/49(NB), with thymalfasin (thymosin alpha1), sterile powder, manufacturer PATHEON ITALIA S.p.A in Italy, and DKSH (Thailand) Ltd as license holder. Thai FDA — ZADAXIN, 1C 94/49(NB); database dated 30 June 2025
The database is dated 30 June 2025. Finding this entry does not confirm today’s registration status, availability, or the authenticity of another seller’s Tα1 vial. Indications in foreign product information should not automatically be described as Thai-approved indications.
What should be checked for an actual product?
Check the label, trade name, manufacturer, formulation, batch number and matching documentation. Thymalfasin studies and a ZADAXIN registration do not verify another brand’s quality or effects. A research label or analytical certificate alone does not establish authorization for human use.
ZADAXIN information lists hypersensitivity as a contraindication and includes important restrictions for people deliberately immunosuppressed, such as transplant recipients. Immune-related treatment requires assessment of the condition and current medicines; more immune stimulation is not automatically beneficial. BPOM Indonesia — ZADAXIN product information
Frequently asked questions
Are thymosin alpha-1 and thymalfasin the same name?
Thymalfasin refers to synthetic thymosin alpha-1. ZADAXIN is one trade name; each product still needs separate identification.
Can thymosin alpha-1 replace TB-500?
They should not be treated as interchangeable. The names do not identify the same substance, and evidence cannot be transferred between them.
Is ZADAXIN listed in the Thai database?
Yes. Entry 1C 94/49(NB) appears in the Thai FDA database dated 30 June 2025. This does not confirm current status or an individual seller’s product.
Are general immune-boosting and anti-aging benefits established?
The cited studies involve specific patient groups. They do not establish those general benefits or the effects of every brand.
Related reading
General information enquiries
For questions about names, labels or documents, contact LINE: @musclestationth. Personal treatment decisions require a qualified healthcare professional.
Primary sources
- BPOM Indonesia — ZADAXIN product information
- Thai FDA — ZADAXIN, 1C 94/49(NB); database dated 30 June 2025
- Wu et al., 2025 — TESTS randomized phase 3 sepsis trial
- BMJ, 30 May 2025 — Correction to the TESTS trial
- Xu et al., 2026 — GATES prospective gastric cancer study
Information checked: 11 September 2026. Educational information; no seller’s product or batch has been authenticated.