Peptide reference
Thymosin alpha-1
Thymalfasin ·Zadaxin ·Tα1 ·TA1
What cited sources report about Thymosin alpha-1
Thymosin alpha-1 (thymalfasin) is a synthetic 28-amino-acid N-acetylated peptide identical to the natural thymic hormone first isolated from bovine thymus. The compound is marketed internationally under the trade name Zadaxin and is approved in more than 30 countries (including Italy) for indications that vary by jurisdiction — most commonly chronic hepatitis B and as a vaccine adjuvant. Thymosin alpha-1 has no FDA-approved indication in the United States. The summaries below report what individual cited sources state; this page does not assert claims beyond what those sources report.
Li et al. (2026) — Immunopharmacology and Immunotoxicology
An open-label randomized controlled trial (NCT03082885) at the Third Affiliated Hospital of Sun Yat-sen University enrolled 73 patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) and assigned them to standard medical therapy (n=38) or standard medical therapy plus thymosin α1 (n=35). The authors reported improved 90-day transplant-free survival in the thymosin α1 group, alongside reduced regulatory-T-cell frequencies and moderated late-stage inflammatory cytokines.
Tα1 improves clinical outcomes in HBV-ACLF by rebalancing the immune response—mitigating excessive inflammation and preventing immune paralysis by modulating T-cell differentiation and cytokine production.
Chen et al. (2026) — Virulence
A 2026 in vitro study from Shanghai-based investigators reported that thymosin α1 stimulated THP-1-derived dendritic cells to secrete the IL-15/IL-15Rα complex, which was associated with reduced HIV latency markers in a cell-line model. The authors framed the work as preliminary mechanistic support and explicitly limited their conclusions to in vitro findings.
Sun Yat-sen University HBV-ACLF Trial — ClinicalTrials.gov NCT03082885
The registered open-label randomized controlled trial evaluated thymosin α1 plus standard medical therapy versus standard medical therapy alone in HBV-related acute-on-chronic liver failure, with 90-day transplant-free survival as the primary endpoint. Results were posted in 2026 alongside the published Immunopharmacology and Immunotoxicology paper.
DrugBank DB04900
The DrugBank entry classifies thymalfasin (thymosin alpha-1) as approved in multiple international markets, summarizing the immunomodulatory mechanism (toll-like-receptor activation, T-cell maturation) and listing approved indications by country. The record reports no U.S. FDA marketing authorization for any indication.