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Thymosin Alpha-1

A thymic peptide approved in multiple countries for immune modulation, particularly in hepatitis and as a vaccine adjuvant.

StrongWell-Studied

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This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician

What is Thymosin Alpha-1?

Thymosin Alpha-1 is a 28-amino-acid peptide that is naturally produced by the thymus gland. It plays a central role in immune system maturation and regulation. The synthetic version (Zadaxin/Thymalfasin) is approved in over 35 countries for the treatment of hepatitis B and C, and as a vaccine adjuvant. It is not FDA-approved in the United States but is available through compounding pharmacies.

Why People Talk About It

Immune system modulation

Strong

Hepatitis B and C treatment (approved internationally)

Strong

Vaccine response enhancement

Moderate

Immune support during illness

Emerging

How It Works

Thymosin Alpha-1 helps train and regulate your immune system. It supports the maturation of T-cells (key immune fighters) and helps balance the immune response — boosting it when needed and calming it when overactive.

Common Questions

Safety Information

Important Safety Notes

Common Side Effects

Injection site reactions (mild)Generally very well tolerated

Cautions

  • Not FDA-approved in the US
  • Should be used under clinician guidance
  • May not be appropriate for those on immunosuppressive therapy without careful monitoring

What We Don't Know

While extensively studied internationally, some applications discussed in the wellness space go beyond the studied indications.

Published Research

32 studies

Thymosin alpha 1 alleviates inflammation and prevents infection in patients with severe acute pancreatitis through immune regulation: a systematic review and meta-analysis

Meta-AnalysisPMID: 40599771

Thymosin Alpha 1 Plus Routine Treatment for the Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Meta-AnalysisPMID: 39648386

The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression

Meta-AnalysisPMID: 37845598

The clinical efficacy and adverse effects of Entecavir plus Thymosin alpha-1 combination therapy versus Entecavir Monotherapy in HBV-related cirrhosis: a systematic review and meta-analysis

Meta-AnalysisPMID: 33076834

Interventions for treating traumatised permanent front teeth: avulsed (knocked out) and replanted

Meta-AnalysisPMID: 30720860

Phyllanthus species versus antiviral drugs for chronic hepatitis B virus infection

Meta-AnalysisPMID: 23633363

[Treatment with interferon and thymosin alpha-1 versus interferon monotherapy for HBeAg positive chronic hepatitis B: a meta-analysis]

Meta-AnalysisPMID: 21272455

Thymic peptides for treatment of cancer patients

Meta-AnalysisPMID: 21328265

Interventions for treating traumatised permanent front teeth: avulsed (knocked out) and replanted

Meta-AnalysisPMID: 20091594

Comparison of the efficacy of thymosin alpha-1 and interferon alpha in the treatment of chronic hepatitis B: a meta-analysis

Meta-AnalysisPMID: 18078676

Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials

Systematic ReviewPMID: 38308608

Immune-Enhancing Treatment among Acute Necrotizing Pancreatitis Patients with Metabolic Abnormalities: A Post Hoc Analysis of a Randomized Clinical Trial

Randomized Controlled TrialPMID: 38356344

A pilot trial of Thymalfasin (Ta1) to prevent covid-19 infection and morbidities in renal dialysis patients: Preliminary report

Randomized Controlled TrialPMID: 36881981

Immune enhancement in patients with predicted severe acute necrotising pancreatitis: a multicentre double-blind randomised controlled trial

Randomized Controlled TrialPMID: 35713670

The effect of thymopentin add-on in hepatitis B e antigen positive chronic hepatitis B after virus suppression by peginterferon plus entecavir therapy

Randomized Controlled TrialPMID: 30860474

Combination of entecavir with thymosin alpha-1 in HBV-related compensated cirrhosis: a prospective multicenter randomized open-label study

Randomized Controlled TrialPMID: 30063860

The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial

Randomized Controlled TrialPMID: 23327199

Thymosin alpha-1 with peginterferon alfa-2a/ribavirin for chronic hepatitis C not responsive to IFN/ribavirin: an adjuvant role?

Randomized Controlled TrialPMID: 22233415

Efficacy of thymosin α-1 plus peginterferon α-2a combination therapy compared with peginterferon α-2a monotherapy in HBeAg-positive chronic hepatitis B: a prospective, multicenter, randomized, open-label study

Randomized Controlled TrialPMID: 22726105

Thymosin alpha 1 is associated with improved cellular immunity and reduced infection rate in severe acute pancreatitis patients in a double-blind randomized control study

Randomized Controlled TrialPMID: 20549321

Large randomized study of thymosin alpha 1, interferon alfa, or both in combination with dacarbazine in patients with metastatic melanoma

Randomized Controlled TrialPMID: 20194853

Effect of thymosin-α(1) on T-helper 1 cell and T-helper 2 cell cytokine synthesis in patients with hepatitis B virus e antigen-positive chronic hepatitis B

Randomized Controlled TrialPMID: 21227010

A new immunomodulatory therapy for severe sepsis: Ulinastatin Plus Thymosin {alpha} 1

Randomized Controlled TrialPMID: 19033321

[Immune and inflammation confusion in severe sepsis and effects of bi-immunomodulation therapy: a prospective, randomized, controlled clinical trial]

Randomized Controlled TrialPMID: 19595251

Combination therapy of thymosin alpha-1 and lamivudine for HBeAg positive chronic hepatitis B: A prospective randomized, comparative pilot study

Randomized Controlled TrialPMID: 18410608

Thymosin alpha 1 provides short-term and long-term benefits in the reimplantation of avulsed teeth: a double-blind randomized control pilot study

Randomized Controlled TrialPMID: 18534287

Thymosin alpha1- and ulinastatin-based immunomodulatory strategy for sepsis arising from intra-abdominal infection due to carbapenem-resistant bacteria

Randomized Controlled TrialPMID: 18613793

[The prophylactic effect of thymosin alpha 1 on the acute exacerbation of chronic obstructive pulmonary disease]

Randomized Controlled TrialPMID: 18798500

Thymosin alpha 1 as an adjunct to influenza vaccination in the elderly: rationale and trial summaries

Randomized Controlled TrialPMID: 17600281

Efficacy of thymosin alpha-1 and interferon alpha in treatment of chronic viral hepatitis B: a randomized controlled study

Randomized Controlled TrialPMID: 17075991

Thymosin alpha 1: A comprehensive review of the literature

ReviewPMID: 33362999

Immune Modulation with Thymosin Alpha 1 Treatment

ReviewPMID: 27450734

Always consult a qualified clinician

This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician

Research Insights

Related Peptides

Quick Facts

Class
Thymic Peptide
Evidence
Strong
Safety
Well-Studied
Updated
Feb 2026
Citations
32PubMed

Also known as

Tα1ZadaxinThymalfasin

Tags

Immune SupportApproved InternationallyHepatitisImmune Modulation

Related Goals

Evidence Score

Overall Confidence82%

Clinical Trials

View Clinical Trials

Links to ClinicalTrials.gov for reference. Listing does not imply endorsement.

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