Thymosin Alpha-1 5 mg

Thymosin Alpha-1 5 mg research-grade lyophilized peptide powder in a glass vial. Also known as Thymalfasin, this 28-amino-acid peptide is a key component of thymosin fraction 5 and is studied as an immunomodulatory peptide in models of T-cell maturation, immune restoration and cytokine signaling.

Research Overview

Thymosin Alpha-1 (Tα1) is a naturally occurring thymic peptide recognized for its immunomodulatory properties. In experimental systems it is used to explore T-cell maturation and differentiation, restoration of immune responsiveness and regulation of cytokine and chemokine profiles.

Primary Research Areas

• Immune modulation & restoration: models evaluating T-cell numbers, function and recovery of impaired immune responses [4,5].
• T-cell maturation & thymic function: experimental work on helper T-cell differentiation, thymic output and related signaling [5].
• Cytokine & chemokine signaling: studies tracking IL, IFN and chemokine profiles in response to immune challenges [7,8].
• Dendritic cell & antigen presentation models: systems examining antigen-presenting cell function and coordination of adaptive immune responses [7].
• Chronic hepatitis B: in one trial, 62 people with hepatitis B were randomised to six months of thymosin alpha-1, 1.6 mg twice a week, or interferon alfa. Six months after treatment ended, 48.3% of the peptide group had normal enzymes with no detectable virus, against 27.3% on interferon. That still leaves half the patients unchanged [1].
• Sepsis and the death rate: the largest trial randomised 1106 adults with sepsis to thymosin alpha-1 or placebo every 12 hours for seven days: 23.4% of the treated group died at 28 days against 24.1% on placebo, and no secondary or safety outcome differed. In the trial designed to settle it, the peptide did not save lives [3,4].
• Severe COVID-19: among 76 severely ill patients in two Wuhan hospitals, 11.1% of those given thymosin alpha-1 died against 30.0% of those who were not, and treated patients recovered CD8 and CD4 T-cell numbers. This is a look back through hospital records rather than a randomised trial, so the two groups may have differed [5].
• Infections in people on dialysis: in an ongoing trial, 194 patients on haemodialysis were randomised to eight weeks of 1.6 mg twice weekly or to no drug; at the interim report there had been 3 deaths in the treated group against 7 in the control, and 5 against 7 COVID-related serious events. This is a small unblinded trial [6].
• Cystic fibrosis: in mice with cystic fibrosis and in cells from patients carrying the commonest mutation, thymosin alpha-1 damped inflammation and increased the amount, stability and chloride-channel activity of the faulty CFTR protein. No patient has been treated on this basis, and an independent laboratory published a direct contradiction of the CFTR finding [8].
• How it is tolerated: across the hepatitis B trials the peptide caused far less trouble than interferon: in one trial no side effects were recorded in the peptide arm, and in another the only complaint was discomfort where the injections went in. These were trials of a few dozen patients each, lasting six to twelve months [1,2].

References

1. You J, Zhuang L, Cheng HY, et al. Efficacy of thymosin alpha-1 and interferon alpha in treatment of chronic viral hepatitis B: a randomized controlled study. World J Gastroenterol. 2006;12(41):6715-21. PMID 17075991. doi:10.3748/wjg.v12.i41.6715
2. Andreone P, Cursaro C, Gramenzi A, et al. A randomized controlled trial of thymosin-alpha1 versus interferon alfa treatment in patients with hepatitis B e antigen antibody–and hepatitis B virus DNA–positive chronic hepatitis B. Hepatology. 1996;24(4):774-7. PMID 8855175. doi:10.1002/hep.510240404
3. Wu J, Pei F, Zhou L, et al. The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial. BMJ. 2025;388:e082583. PMID 39814420. doi:10.1136/bmj-2024-082583
4. Wu J, Zhou L, Liu J, et al. The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial. Crit Care. 2013;17(1):R8. PMID 23327199. doi:10.1186/cc11932
5. Liu Y, Pan Y, Hu Z, et al. Thymosin Alpha 1 Reduces the Mortality of Severe Coronavirus Disease 2019 by Restoration of Lymphocytopenia and Reversion of Exhausted T Cells. Clin Infect Dis. 2020;71(16):2150-2157. PMID 32442287. doi:10.1093/cid/ciaa630
6. Tuthill CW, Awad A, Parrigon M, et al. A pilot trial of Thymalfasin (Ta1) to prevent covid-19 infection and morbidities in renal dialysis patients: Preliminary report. Int Immunopharmacol. 2023;117:109950. PMID 36881981. doi:10.1016/j.intimp.2023.109950
7. Romani L, Bistoni F, Gaziano R, et al. Thymosin alpha 1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling. Blood. 2004;103(11):4232-9. PMID 14982877. doi:10.1182/blood-2003-11-4036
8. Romani L, Oikonomou V, Moretti S, et al. Thymosin α1 represents a potential potent single-molecule-based therapy for cystic fibrosis. Nat Med. 2017;23(5):590-600. PMID 28394330. doi:10.1038/nm.4305