peptidefix

Peptides / Thymosin alpha-1 / United Kingdom

Thymosin alpha-1 in the United Kingdom

Legal status, what it is, and the listed suppliers in the United Kingdom that list it.

Legal status in the United Kingdom

Not an approved medicine. The MHRA products register returns no result for thymalfasin (checked 2026-09-22).

As understood at 2026-09-22. Verify with the MHRA.

What Thymosin alpha-1 is

Thymosin alpha-1 is a 28-amino-acid peptide originally isolated from thymus tissue, the gland where T cells mature. The synthetic form is called thymalfasin. It has been through a large clinical programme as an immune modulator, mostly outside the UK, US and Australia, and is not an approved medicine in any of the three.

Full Thymosin alpha-1 page: targets and research →

Listed suppliers in the United Kingdom

4 of the 10 suppliers we list in the United Kingdom list Thymosin alpha-1. Listed, not endorsed: each row is the supplier’s own stated terms.

Bluewell Peptides United Kingdom All Bluewell products are supplied strictly for laboratory research use only. They are not intended for human consumption, medical use, therapeutic use, diagnostic use, or veterinary use. Pure Peptides UK United Kingdom All products are for research use only. Research Peptide United Kingdom Supplied strictly for research and laboratory use only and not for human or veterinary consumption. UK Peptides United Kingdom All products are sold exclusively for in-vitro research. They are not for human or veterinary use.

Clinical Research

The efficacy and safety of thymosin alpha1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial
Wu J, Pei F, Zhou L, et al. (2025). BMJ. human 1,106 adults with sepsis across 22 centres in China; phase 3, double-blind, placebo-controlled
A Pilot Trial of Thymalfasin (Thymosin-alpha-1) to Treat Hospitalized Patients With Hypoxemia and Lymphocytopenia Due to Coronavirus Disease 2019 Infection
Shehadeh F, Benitez G, Mylona EK, et al. (2023). The Journal of Infectious Diseases. human 49 hospitalised patients with COVID-19, low oxygen levels and low lymphocyte counts; open-label, randomised against standard care
The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression
Soeroto AY, Suryadinata H, Yanto TA, Hariyanto TI (2023). Inflammopharmacology. meta-analysis n/a (pooled analysis of 8 studies in moderate to critical COVID-19)
Thymosin Alpha 1 Plus Routine Treatment for the Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis
Cao A, Feng F, Zhou X (2024). Journal of the College of Physicians and Surgeons Pakistan. meta-analysis n/a (39 randomised trials, 3,329 patients with acute exacerbation of COPD)