Thymosin Alpha-1 (Tα1)
Also Known AsTα1 · Ta1 · Thymalfasin · Zadaxin
Originally isolated from thymic tissue (Thymosin Fraction 5) by Allan Goldstein at George Washington University in the 1970s. Thymosin alpha-1 is a 28-amino-acid peptide that is the primary immunomodulatory component of thymus-derived peptide fractions. Approved as Zadaxin in over 35 countries for hepatitis B and C.
Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-AsnHow Thymosin Alpha-1 Works
T-Cell Maturation & Differentiation
Promotes the maturation of T-cell precursors into functional CD4+ and CD8+ T-cells through thymic education pathways. Restores T-cell populations in immunocompromised states and enhances the ratio of mature to immature T-cells.
Dendritic Cell Activation via TLR Signaling
Activates dendritic cells through Toll-like receptor 9 (TLR9) and MyD88-dependent signaling, enhancing antigen presentation and bridging innate and adaptive immunity. This is the primary mechanism by which Tα1 amplifies immune responses to pathogens and vaccine antigens.
NK Cell & Macrophage Enhancement
Increases natural killer cell cytotoxicity and macrophage phagocytic activity. Enhances production of IFN-α, IFN-γ, and IL-2, amplifying both innate defense and adaptive immune coordination.
Published Research
Hepatitis B & C
StrongMultiple randomized controlled trials demonstrate that thymosin alpha-1 improves viral clearance, HBeAg seroconversion, and sustained virologic response when used as monotherapy or in combination with interferon/antivirals. Approved as Zadaxin in 35+ countries for chronic hepatitis B. Meta-analyses confirm efficacy with excellent tolerability.
Vaccine Adjuvant & Immunopotentiation
StrongClinical trials demonstrate enhanced antibody responses when thymosin alpha-1 is co-administered with influenza, hepatitis B, and other vaccines, particularly in elderly and immunocompromised populations with typically poor vaccine responses. Mechanism involves enhanced dendritic cell antigen presentation.
Oncology Immunotherapy
ModerateUsed as immunomodulatory adjunct in hepatocellular carcinoma, melanoma, and lung cancer studies. Phase II/III trials show improved immune parameters and, in some studies, improved survival when combined with standard chemotherapy. Mechanism involves restoration of T-cell-mediated tumor immunosurveillance.
Sepsis & Critical Illness
ModerateRandomized controlled trials in severe sepsis patients demonstrate improved immune cell counts, reduced secondary infection rates, and improved 28-day mortality. A Chinese RCT (n=361) showed significant reduction in mortality in severe sepsis patients with immunosuppression. Used extensively in ICU settings in Asia.
Immune Reconstitution
ModerateStudied for immune reconstitution following bone marrow transplant, chemotherapy-induced immunosuppression, and age-related immune decline (immunosenescence). Preclinical and clinical data show restoration of T-cell numbers, CD4/CD8 ratios, and functional immune competence.
Safety Profile
Thymosin alpha-1 has one of the most extensive safety databases of any peptide therapy, with over 4,400 patients in clinical trials across 4+ decades. Approved in 35+ countries. No significant adverse effects reported beyond mild injection site reactions. No immunosuppressive rebound after discontinuation. Compatible with concurrent antiviral, chemotherapy, and vaccine administration.
Handling & Storage
Reconstitute with bacteriostatic water. Thymosin alpha-1 is highly soluble. Store reconstituted solution at 2-8°C. Lyophilized powder stable at -20°C. The N-terminal acetylation is essential for biological activity — verify intact acetyl group in analytical testing.
Peer-Reviewed Literature
- 1
Thymosin α1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling
Romani L, Bistoni F, Gaziano R, et al.
- 2
From lab to bedside: emerging clinical applications of thymosin α1
Goldstein AL, Goldstein AL.
- 3
The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial
Wu J, Zhou L, Liu J, et al.
- 4
Thymosin α1: from bench to bedside
Garaci E, Favalli C, Pica F, et al.
- 5
Thymalfasin: clinical experience and future directions
Tuthill C, Rios I, McBeath R.
International Immunopharmacology, 2010DOI
Thymosin Alpha-1 FAQ
What is Thymosin Alpha-1?
Thymosin Alpha-1 (Tα1) is a 28-amino-acid peptide originally isolated from thymus tissue by Allan Goldstein. It is the primary immunomodulatory component of thymic hormone preparations and is approved in over 35 countries as Zadaxin for the treatment of chronic hepatitis B and as an immune system modulator.
Is Thymosin Alpha-1 approved for medical use?
Yes. Thymosin Alpha-1 is approved as Zadaxin (thymalfasin) in over 35 countries including China, India, and multiple European and South American nations for chronic hepatitis B, as a vaccine adjuvant, and as immunotherapy for certain cancers. It has over 4 decades of clinical use data.
How is Thymosin Alpha-1 different from TB-500?
They are entirely different peptides from the same thymus-derived family. Thymosin Alpha-1 (28 amino acids) is primarily an immune modulator that enhances T-cell and dendritic cell function. TB-500/Thymosin Beta-4 (43 amino acids) primarily promotes tissue repair through actin sequestration and cell migration. Their mechanisms, targets, and research applications are distinct.
Can Thymosin Alpha-1 enhance vaccine responses?
Yes. Multiple clinical trials demonstrate that co-administration of Thymosin Alpha-1 with influenza, hepatitis B, and other vaccines significantly improves antibody responses, particularly in elderly and immunocompromised individuals who typically have poor vaccine responses. The mechanism involves enhanced dendritic cell-mediated antigen presentation.
Thymosin Alpha-1 Products
All compounds 99%+ purity, verified by Janoshik Analytical. GMP-manufactured lyophilized powder.
Thymosin Alpha-1
10mgImmune system supercharger — activates your T-cells and dendritic cells for maximum pathogen defense. Used clinically worldwide for hepatitis B and immune support.
- Supercharges immune system function and resilience
- Used clinically for hepatitis B, cancer immunotherapy support
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TB-500
10mgYour body's built-in repair signal — speeds muscle recovery, heals stubborn injuries, and reduces chronic inflammation and pain.
- Dramatically speeds muscle and tissue recovery
- Reduces inflammation and chronic pain
Thymalin
100mgThymus gland reactivator — restores the immune organ that shrinks with age, reactivating T-cell production and immune surveillance for full-spectrum immune recovery.
- Restores thymus gland function that declines with age
- Reactivates immune system in aging and immunocompromised states
LL-37
5mgYour body's natural antibiotic — destroys bacteria, viruses, and fungi on contact, breaks up stubborn biofilms, and accelerates wound healing.
- Broad-spectrum antimicrobial — kills bacteria, viruses, and fungi
- Accelerates wound healing and tissue repair
Disclaimer: This monograph is provided for educational and research purposes only. G26x Peptides products are sold exclusively as research chemicals. They are not intended for human consumption, therapeutic use, or as dietary supplements. All research should be conducted in compliance with applicable laws and institutional review board protocols. Information presented here is sourced from published peer-reviewed literature and does not constitute medical advice.