Evidence Grade C — Moderate human evidence. 576 published studies, 345 human. 0 registered clinical trials.
Medically reviewed by a licensed medical professional
Thymosin alpha-1 is an immune-modulating peptide originally isolated from the thymus gland. It has been studied extensively across conditions including hepatitis B, liver cancer, sepsis, and as a vaccine adjuvant. Its regulatory status varies widely by jurisdiction — it is used clinically in parts of Asia, Europe, and South America but has not been reviewed by the FDA or EMA.
Thymosin Alpha-1 is also known by these brand and alternate names:
576 published studies: 345 human, 185 animal, 123 in-vitro, 77 reviews
Thymosin alpha-1 has been studied across multiple indications including hepatitis B, hepatocellular carcinoma, sepsis, and as a vaccine adjuvant. A meta-analysis of hepatitis B trials reported a statistically significant treatment effect, but the largest individual Phase III trial did not reach significance.
The compound has been the subject of extensive clinical research but has not met FDA or EMA approval standards for any indication. Its regulatory status varies widely by jurisdiction — approved in over 35 countries, primarily in Asia and parts of Europe and South America. See also Thymalfasin (#74).
Research suggests thymosin alpha-1 may activate toll-like receptors on dendritic cells and influence T-cell differentiation. A meta-analysis of hepatitis B trials reported a significant treatment effect, though the pivotal Phase III trial did not confirm efficacy. The proposed immunomodulatory mechanisms are based on a combination of in vitro, animal, and clinical studies of varying quality.
Research suggests thymosin alpha-1 has been studied across multiple conditions including hepatitis B, liver cancer, sepsis, and as a vaccine adjuvant. A meta-analysis of hepatitis B trials reported a statistically significant treatment effect, but the largest individual Phase III trial did not reach significance. The largest sepsis trial (TESTS, 1,106 patients) was definitively negative on its primary endpoint. The disconnect between wide international approval (35+ countries) and rejection by the FDA and EMA reflects inconsistent efficacy across rigorous trials. The peptide is well-characterised scientifically and the mechanism (working through toll-like receptors on dendritic cells) is well-described, but clinical outcomes have not consistently matched the preclinical promise.
PeptideTrace tracks 0 registered clinical trials for Thymosin Alpha-1 sourced from ClinicalTrials.gov.
No trials registered on ClinicalTrials.gov for this compound.
Thymosin Alpha-1 (Ta1, thymalfasin) is a 28-amino acid peptide first isolated from Thymosin Fraction 5 by Allan Goldstein at the University of Texas Medical Branch in 1972. Sequence: Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN. Molecular weight: 3,108.28 Da. CAS: 62304-98-7. Molecular formula: C129H215N33O55. Half-life approximately 2 hours. Tmax approximately 1.3 hours (SC). Brand name: Zadaxin (SciClone Pharmaceuticals). Approved in approximately 35+ countries including China and Russia. FDA orphan drug designation only, not FDA approved for general use. Endogenously produced by asparagine endopeptidase cleavage of prothymosin alpha (113-amino acid precursor). Listed here as research_compound for grey-market/unapproved-jurisdiction context.
Research suggests Ta1 acts primarily as an agonist of TLR2 and TLR9 on myeloid and dendritic antigen-presenting cells, with additional activity at TLR3, TLR4, and TLR7. Downstream signaling involves the NF-kappaB, p38 MAPK, and JNK/AP1 pathways. It stimulates dendritic cell maturation and antigen presentation, activates indoleamine 2,3-dioxygenase (IDO) for immune tolerance, promotes T-cell differentiation (CD4+, CD8+, CD3+), enhances Th1 responses with increased IFN-gamma, IL-2, IL-3 production, upregulates MHC class I molecules, and enhances NK cell cytotoxicity. Research also suggests PTEN-mediated inhibition of the PI3K/Akt/mTOR pathway in breast cancer models.
Hepatitis B: A meta-analysis of 5 RCTs (Chan et al., 2001; N=353) found OR 2.67 (95% CI 1.25-5.68) for virological response at 12 months post-treatment. The Chien et al. RCT (1998; N=98) showed 40.6% complete response vs 9.4% control (P=0.004). However, the Phase III Mutchnick trial (1999; N=97) did not confirm efficacy (14% vs 4%, P=0.084). Sepsis: The ETASS trial (Wu et al., 2013; N=361) showed 26.0% vs 35.0% 28-day mortality (P=0.049 log-rank). The definitive TESTS trial (BMJ 2025; N=1,106, double-blind, placebo-controlled) found HR 0.99 (95% CI 0.77-1.27), P=0.93, no significant benefit overall, though a diabetes subgroup showed HR 0.58 (95% CI 0.35-0.99). Cancer: Phase II trials in NSCLC, HCC, and melanoma research suggest reduced chemotherapy toxicity and improved quality of life. FDA granted orphan drug status for HCC, melanoma, and DiGeorge anomaly.
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
Zilucoplan is marketed as Zilbrysq (approved October 2023) for anti-acetylcholine receptor antibody-positive generalised myasthenia gravis in adults. Administered as a daily subcutaneous self-injection. In the RAISE trial, zilucoplan showed statistically significant improvements in both activities of daily living and quantitative muscle strength scores compared to placebo, with improvements evident from week one. Its key differentiator from existing complement inhibitors (eculizumab, ravulizumab) is the self-injectable format — those alternatives require hospital-based intravenous infusions. As with all complement inhibitors, patients require meningococcal vaccination before starting treatment due to increased susceptibility to meningococcal infection.
Vancomycin is marketed as Vancocin and Firvanq (approved 1958, with oral solution Firvanq approved 2018). It is the standard treatment for serious MRSA infections (bloodstream infections, endocarditis, pneumonia, bone infections) and is first-line for severe C. difficile colitis. Vancomycin requires therapeutic drug monitoring — blood levels must be checked regularly to ensure the dose is effective without causing kidney damage or hearing loss. The rise of vancomycin-resistant enterococci (VRE) and occasional vancomycin-intermediate S. aureus (VISA) strains represent ongoing challenges. Despite being nearly 70 years old, vancomycin remains irreplaceable for many serious infections, though newer alternatives like daptomycin and the lipoglycopeptides offer advantages in specific settings.
Bortezomib is marketed as Velcade (approved May 2003) for multiple myeloma and mantle cell lymphoma. Generic versions are available. Originally given intravenously, subcutaneous injection is now preferred as it causes significantly less nerve damage. The VISTA trial established bortezomib-based combination therapy as standard for newly diagnosed myeloma patients ineligible for transplant, with median time to disease progression of 24 months versus 16.6 months with older chemotherapy. Peripheral neuropathy (numbness and tingling in hands and feet) is the main dose-limiting side effect, affecting up to 30% of patients. Bortezomib transformed myeloma from a disease with a median survival of approximately 3 years to one where many patients live a decade or more with sequential treatments.
Evidence Reviews
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making decisions about your health.
