● TIER 3 — Information onlyGRADE BImmune / thymic
Thymosin α1
Thymic immunomodulator. Research verification: Yes (TGA pending). Origin: China (widely used). Citations verified: yes. 4 human study record(s) in the FitClinicMD studies database.
FDA status
Not FDA-approved (Zadaxin approved in other countries).
Compounding (503A/503B)
Listed by FDA under 'nominated but withdrawn' from Category 2 (i.e., no longer in Category 2, but NOT on the 503A bulks list or Category 1)
DEA
Not controlled.
WADA (sport)
Not listed on 2026 Prohibited List (no matching section found)
Mechanism
T-cell maturation, TLR signaling. (East) Thymic peptide immunomodulators.
Human evidence · 4
TESTS (BMJ 2025): multicenter double-blind RCT in sepsis (China, n=1,106) — no 28-day mortality benefit. The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial.
TESTS trial, BMJ 2025 (PMID 39814420; NCT02867267).
Drug review (2001). Thymosin alpha-1.
Lamivudine + thymopentin in chronic hepatitis B.
Reference only. This page summarizes publicly available regulatory and research information about Thymosin α1. It is not a prescription, an endorsement, or an offer to dispense, and regulatory status can change. Clinicians should verify current status before prescribing or compounding.