Thymosin Alpha-1 (TA)

The FDA evaluated twelve proposed uses and reviewed the published trials behind each: hepatitis B, hepatitis C, HIV, COVID-19, vaccine adjuvant use, malignant melanoma, hepatocellular carcinoma, non-small cell lung cancer, sepsis, infection after haematopoietic stem cell transplantation, COPD, and chronic fatigue syndrome. Real randomised controlled work exists and mostly returned no difference. A randomised double-blind placebo-controlled hepatitis B study found undetectable viral DNA in 20 per cent on Ta1 against 21 per cent on placebo. A randomised double-blind placebo-controlled hepatitis C study adding Ta1 to standard care returned a sustained virologic response of 12.7 per cent against 10.5 per cent. An open-label randomised study in 488 patients with stage IV melanoma failed to show a significant difference in overall response rate for any Ta1 regimen. A single-blind randomised study in 361 patients with severe sepsis reported 28-day mortality of 26 per cent against 35 per cent, with no significant difference in intensive-care mortality, length of stay or ventilation time.

What is not established

Effectiveness, for every one of the twelve uses evaluated. The FDA concluded the evidence was insufficient in each, and identified no clinical study at all in chronic fatigue syndrome. Carcinogenicity studies were not identified. The reproductive toxicology study a sponsor described as completed has no published data. The non-clinical pharmacokinetic profile by the subcutaneous route, which is the route actually used, is unknown. As a 28-amino-acid peptide given subcutaneously it may pose a significant immunogenicity risk, potentially amplified by aggregation and peptide-related impurities, and no impurity or aggregate testing appeared in the certificates of analysis reviewed. The nominated 3 mg/mL injectable also exceeds the material's water solubility of 2 mg/mL, and no explanation was provided for how the higher concentration is reached.

What distinguishes Thymosin Alpha-1 (TA)

It is the only compound in this catalogue holding a real national marketing authorisation in Europe, in Italy, and it is still the compound whose regulator concluded most explicitly that the evidence does not support the uses claimed for it. Those two facts belong together, because the approval is what sellers cite and the conclusion is what they omit. The FDA also recorded, in the same review, that a website advertises a compounded subcutaneous Ta1 product as FDA-approved when no such approval exists, so a buyer researching this compound should expect to meet that exact claim.

Sources

1. US FDA. Pharmacy Compounding Advisory Committee, Thymosin Alpha-1 (Ta1) Related Bulk Drug Substances, 4 December 2024
2. US FDA. Certain bulk drug substances for use in compounding that may present significant safety risks
3. World Anti-Doping Agency. The Prohibited List, searched for 'thymosin'
4. ClinicalTrials.gov. NCT04487444, thymalfasin to treat COVID-19 infection
5. ClinicalTrials.gov. NCT04428008, thymosin alpha 1 to prevent COVID-19 in renal dialysis patients

This page describes a compound as a material and summarises published research about it. It is for general and procurement information only. It is not medical advice, not a treatment recommendation, and not guidance on use. Supplied for laboratory and research use, not for human consumption.