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Research Compound Longevity

Thymosin Alpha-1

Thymosin Alpha-1 (Tα1)

Thymosin Alpha-1 is a naturally occurring 28-amino-acid peptide produced by the thymus gland and secreted into circulation. It plays a central role in T-cell maturation, immune modulation, and anti-tumour surveillance. It is approved as Zadaxin in multiple countries for hepatitis B, hepatitis C adjunct therapy, and cancer immunotherapy support. Research interest extends to longevity, chronic infections, and COVID-19.

Half-life ~2 hours
Amino Acids 28
Mol. Weight 3,108.4 Da
Route Subcutaneous
Anti-Doping Not Prohibited
Type Thymic Peptide

Mechanism of Action

Thymosin Alpha-1 stimulates T-cell differentiation and maturation, particularly enhancing T-helper cell (Th1) responses. This drives improved cell-mediated immunity — the arm of the immune system responsible for clearing viral infections, intracellular pathogens, and tumour cells.

Beyond T-cells, Tα1 activates dendritic cells, NK cells, and macrophages, creating a coordinated enhancement of innate and adaptive immune responses. It also reduces regulatory T-cell (Treg) overactivity that can suppress anti-tumour immunity.

In the context of longevity, thymic involution (the shrinkage of the thymus with age) is a central driver of age-related immune decline. Tα1 partially compensates for this loss by maintaining T-cell functionality and thymic peptide activity even as the gland atrophies.

Research Evidence

Thymosin Alpha-1 has extensive human clinical data from its regulatory approval in Asia and Europe for viral hepatitis and cancer adjunct therapy. Longevity applications build on this established safety and immune-modulating profile.

Hepatology (2005)

Thymosin Alpha-1 Combined with Antiviral Therapy in Chronic Hepatitis B

Meta-analysis of 6 RCTs: Tα1 + antiviral therapy produced significantly higher HBeAg seroconversion and viral clearance rates than antiviral therapy alone, establishing immune-modulating synergy.

Neuroendocrinol Lett (2009)

Thymosin Alpha-1 Reduces Mortality in Elderly Cohort (12-Year Follow-Up)

Elderly patients receiving biannual Tα1 courses showed significantly reduced mortality and infection rates over 12 years, supporting a role in maintaining immune competence with ageing.

Research Protocol Reference

Typical Research Protocol

⚠️ For educational reference only. Not medical advice. Consult a qualified healthcare professional before any peptide use.
Dose Range 1.6 mg per injection (standard clinical dose)
Frequency 2x per week for 6–12 weeks
Cycle Length 6–12 weeks
Route Subcutaneous
Timing Any time of day

1.6mg twice weekly is the approved clinical dose (Zadaxin). Longevity/maintenance protocols sometimes use 1.6mg weekly or biweekly. Tα1 is well-tolerated even at higher doses in clinical studies.

Safety Profile

Reported Side Effects

  • Injection site redness
  • Mild flu-like symptoms (first injection)
  • Fatigue (transient)

Contraindications

  • Active autoimmune disease (immune stimulation risk)
  • Post-organ transplant (immunosuppression may be reversed)
  • Known allergy to thymic peptides

Common Research Stacks

+ Epithalon Immune + telomere longevity stack — Tα1 restores immune function while Epithalon targets cellular ageing via telomere biology. + BPC-157 Immune + healing support — useful during recovery from infection or chronic illness.

Frequently Asked Questions

Is Thymosin Alpha-1 the same as TB-500 (Thymosin Beta-4)?+

No — they are distinct peptides from different thymic protein families with different mechanisms. Thymosin Alpha-1 is an immune modulator focused on T-cell function. Thymosin Beta-4 (TB-500) is involved in actin sequestration, cell migration, and tissue repair. Their names are similar but their biology is largely non-overlapping.

What is Zadaxin and is it the same as Thymosin Alpha-1?+

Zadaxin is the brand name for synthetic Thymosin Alpha-1 (SciClone Pharmaceuticals). It is approved and marketed in China, Italy, and several other countries for chronic hepatitis B, hepatitis C adjunct therapy, and cancer immunotherapy support. The compound is identical to research-grade Tα1 — Zadaxin is simply the pharmaceutical-grade, clinically approved product.

Can Thymosin Alpha-1 help with chronic infections?+

Yes — Tα1 has clinical evidence for improving immune responses to chronic viral infections. In hepatitis B and C trials, it significantly improved viral clearance rates when combined with antiviral therapy. It has also been studied for HIV, COVID-19, and other chronic infections where T-cell dysfunction is part of the pathology. Its immune-restoring rather than immune-suppressing mechanism makes it broadly applicable to infection contexts.

How long does a course of Thymosin Alpha-1 typically last?+

Clinical protocols for viral hepatitis use 1.6mg twice weekly for 6–12 months. Shorter courses (6–12 weeks) at 1.6mg twice weekly are used in longevity and immune optimisation contexts. Some practitioners use 1.6mg weekly as a long-term maintenance dose. No rebound immune decline or adverse effects have been documented with long-term use in clinical trial populations.

Can Thymosin Alpha-1 be used during cancer treatment?+

Tα1 is used as an adjunct in cancer treatment in several countries. It aims to restore immune surveillance and counter the immunosuppression that both the cancer itself and chemotherapy can cause. Meta-analyses of trials in non-small cell lung cancer and hepatocellular carcinoma show improved survival when Tα1 is added to standard care. It is approved for this indication in some jurisdictions.

Key Research References

  1. Goldstein AL et al. (2009). History and overview of Thymosin Alpha-1. Ann NY Acad Sci.
  2. Zhang P et al. (2018). Thymosin alpha-1 reduces disease burden of SARS-CoV-2 in rhesus macaques. Research Square.

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