Skip to content
Dr. Grey AI

Peptide

Thymosin Alpha-1

Thymosin Alpha-1 (Tα1) is a 28-amino acid immunomodulatory peptide originally isolated from thymic tissue. It enhances T-cell function, modulates innate and adaptive immune responses, and has been approved in over 35 countries for treatment of chronic hepatitis B and as an immune adjuvant. Clinical research supports its use in viral hepatitis, sepsis, and as adjunctive cancer therapy, with a favorable safety profile across numerous trials.

Research notice. This page is for education and research. Peptides may not be FDA-approved for human use and may only be legally available for research. Talk to a qualified clinician before considering any peptide.

Best evidence
Grade B
Conditions studied
5
Outcomes
13
Graded outcomes
0661

Evidence by condition

  • Strong
  • Moderate
  • Limited
  • Very limited

5 conditions, plus general outcomes

Immune Function

Immune Function: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
T-Cell Count

Moderate Increase

Improves (the measure goes up)Moderate effect13 studies580 people

Studies that measured t-cell count

and 3 more in the citations list

CD4/CD8 Ratio

Moderate Improvement

Improves (the measure goes up)Moderate effect4 studies420 people

Studies that measured cd4/cd8 ratio

NK Cell Activity

Moderate Increase

Improves (the measure goes up)Moderate effect3 studies210 people

Studies that measured nk cell activity

Sepsis

Sepsis: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
HLA-DR Expression

Moderate Restoration

Improves (the measure goes up)Moderate effect5 studies340 people

Studies that measured hla-dr expression

28-Day Mortality

Moderate Reduction

Improves (the measure goes down)Moderate effect3 studies890 people

Studies that measured 28-day mortality

Secondary Infection Rate

Moderate Reduction

Improves (the measure goes down)Moderate effect4 studies280 people

Studies that measured secondary infection rate

Hepatitis B

  • HBeAg Seroconversion: improves
  • ALT Normalization: improves
  • HBV DNA Clearance: improves
Hepatitis B: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
HBeAg Seroconversion

Moderate Improvement

Improves (the measure goes up)Moderate effect3 studies485 people

Studies that measured hbeag seroconversion

ALT Normalization

Moderate Improvement

Improves (the measure goes down)Moderate effect3 studies520 people

Studies that measured alt normalization

HBV DNA Clearance

Moderate Improvement

Improves (the measure goes up)Moderate effect3 studies380 people

Studies that measured hbv dna clearance

General Cancer Care and Prevention

  • Overall Survival (Adjuvant): improves
  • Chemotherapy Tolerance: improves
General Cancer Care and Prevention: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
Overall Survival (Adjuvant)

Small Improvement

Improves (the measure goes up)Small effect6 studies720 people

Studies that measured overall survival (adjuvant)

Chemotherapy Tolerance

Moderate Improvement

Improves (the measure goes up)Moderate effect2 studies410 people

Studies that measured chemotherapy tolerance

Hepatitis C

  • Viral Load Reduction: improves
Hepatitis C: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
Viral Load Reduction

Small Decrease

Improves (the measure goes down)Small effect3 studies290 people

Studies that measured viral load reduction

General

  • Pain: improves
General: outcomes studied for Thymosin Alpha-1
GradeOutcomeEffectSizeStudiesPeopleStudies list
Pain

2 preclinical studies support this finding. Primarily preclinical evidence.

Improves (the measure goes down)Small effect3 studies

Studies that measured pain

Key findings

  • T-Cell CountImmune FunctionImproves (the measure goes up)
  • HLA-DR ExpressionSepsisImproves (the measure goes up)
  • CD4/CD8 RatioImmune FunctionImproves (the measure goes up)

Studies cited

55 studies from PubMed

  1. Thymosin alpha 1 alleviates inflammation and prevents infection in patients with severe acute pancreatitis through immune regulation: a systematic review and meta-analysis.Frontiers in immunology, 2025 · PMID 40599771
  2. The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial.BMJ (Clinical research ed.), 2025 · PMID 39814420
  3. The efficacy and safety of thymosin alpha-1 combined with lenvatinib plus sintilimab in unresectable hepatocellular carcinoma: a retrospective study.Scientific reports, 2025 · PMID 40263352
  4. PD-1 inhibitor combined with SBRT, GM-CSF, and thymosin alpha-1 in metastatic breast cancer: A case report and literature review.Medicine, 2024 · PMID 39183403
  5. Thymosin α1 reverses oncolytic adenovirus-induced M2 polarization of macrophages to improve antitumor immunity and therapeutic efficacy.Cell reports. Medicine, 2024 · PMID 39357524
  6. Thymosin Alpha 1 Plus Routine Treatment for the Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.Journal of the College of Physicians and Surgeons--Pakistan : JCPSP, 2024 · PMID 39648386
  7. Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials.Alternative therapies in health and medicine, 2024 · PMID 38308608
  8. Thymosin α-1 in cancer therapy: Immunoregulation and potential applicationsInt Immunopharmacol, 2023 · PMID 36812669
  9. Thymosin alpha 1 - Reimagine its broader applications in the immuno-oncology eraInt Immunopharmacol, 2023 · PMID 36871535
  10. The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression.Inflammopharmacology, 2023 · PMID 37845598
  11. Thymosin α-1 Reverses M2 Polarization of Tumor-Associated Macrophages during Efferocytosis.Cancer research, 2022 · PMID 35364609
  12. Thymosin alpha 1 as an adjuvant to hyperthermic intraperitoneal chemotherapy in an experimental model of peritoneal metastases from colonic carcinoma.International immunopharmacology, 2022 · PMID 35994852
  13. Thymosin alpha-1 therapy improves postoperative survival after curative resection for solitary hepatitis B virus-related hepatocellular carcinoma: A propensity score matching analysis.Medicine, 2021 · PMID 34011034
  14. Combination of Gemcitabine and Thymosin alpha 1 exhibit a better anti-tumor effect on nasal natural killer/T-cell lymphoma.International immunopharmacology, 2021 · PMID 34119916
  15. Thymosin alpha 1 exerts beneficial extrapulmonary effects in cystic fibrosis.European journal of medicinal chemistry, 2021 · PMID 33071052
  16. Thymosin α1 therapy in critically ill patients with COVID-19: A multicenter retrospective cohort studyInt Immunopharmacol, 2020 · PMID 32795897
  17. Immunopotentiator thymosin alpha-1 attenuates inflammatory pain by modulating the Wnt3a/β-catenin pathway in spinal cord.Neuroreport, 2020 · PMID 31764244
  18. Thymosin Alpha 1 Reduces the Mortality of Severe Coronavirus Disease 2019 by Restoration of Lymphocytopenia and Reversion of Exhausted T Cells.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2020 · PMID 32442287
  19. 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.BMC gastroenterology, 2020 · PMID 33076834
  20. Thymosin alpha-1; a natural peptide inhibits cellular proliferation, cell migration, the level of reactive oxygen species and promotes the activity of antioxidant enzymes in human lung epithelial adenocarcinoma cell line (A549).Environmental toxicology, 2019 · PMID 31067016
  21. Thymosin Alpha-1 Inhibits Complete Freund's Adjuvant-Induced Pain and Production of Microglia-Mediated Pro-inflammatory Cytokines in Spinal Cord.Neuroscience bulletin, 2019 · PMID 30790216
  22. Antioxidant and angiotensin-converting enzyme (ACE) inhibitory activity of thymosin alpha-1 (Thα1) peptide.Bioorganic chemistry, 2019 · PMID 30974297
  23. Thymosin alpha 1 treatment for patients with sepsisExpert Opin Biol Ther, 2018 · PMID 30063866
  24. Immune Modulation with Thymosin Alpha 1 TreatmentVitam Horm, 2016 · PMID 27450734
  25. Thymosin alpha1 based immunomodulatory therapy for sepsis: a systematic review and meta-analysisInt J Infect Dis, 2015 · PMID 25532482
  26. Thymosin alpha-1 treatment in chronic hepatitis B.Expert opinion on biological therapy, 2015 · PMID 25640173
  27. Historical review of thymosin α 1 in infectious diseases.Expert opinion on biological therapy, 2015 · PMID 26098768
  28. Thymosin α1 and cancer: action on immune effector and tumor target cellsAnn N Y Acad Sci, 2012 · PMID 23045967
  29. Effect of thymosin alpha-1 on subpopulations of Th1, Th2, Th17, and regulatory T cells (Tregs) in vitroBraz J Med Biol Res, 2012 · PMID 22245858
  30. Thymosin-alpha 1 (Zadaxin) enhances the immunogenicity of an adjuvated pandemic H1N1v influenza vaccine (Focetria) in hemodialyzed patients: a pilot study.Vaccine, 2012 · PMID 22178096
  31. Thymosin alpha-1 with peginterferon alfa-2a/ribavirin for chronic hepatitis C not responsive to IFN/ribavirin: an adjuvant role?Journal of viral hepatitis, 2012 · PMID 22233415
  32. [Treatment with interferon and thymosin alpha-1 versus interferon monotherapy for HBeAg positive chronic hepatitis B: a meta-analysis].Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology, 2011 · PMID 21272455
  33. Utility of thymosin alpha-1 (Zadaxin) as a co-adjuvant in influenza vaccines: a review.Journal of preventive medicine and hygiene, 2011 · PMID 22010537
  34. Transcription profile of human lymphocytes following in vitro treatment with thymosin alpha-1.Annals of the New York Academy of Sciences, 2010 · PMID 20536445
  35. Thymosin alpha 1 for treatment of hepatitis C virus: promise and proof.Annals of the New York Academy of Sciences, 2010 · PMID 20536461
  36. Treatment with lamivudine versus lamivudine and thymosin alpha-1 for e antigen-positive chronic hepatitis B patients: a meta-analysis.Virology journal, 2009 · PMID 19467157
  37. Comparison of the efficacy of thymosin alpha-1 and interferon alpha in the treatment of chronic hepatitis B: a meta-analysis.Antiviral research, 2008 · PMID 18078676
  38. Efficacy of thymosin alpha-1 and interferon alpha in treatment of chronic viral hepatitis B: a randomized controlled study.World journal of gastroenterology, 2006 · PMID 17075991
  39. Thymalfasin (thymosin-alpha 1) therapy in patients with chronic hepatitis B.Journal of gastroenterology and hepatology, 2004 · PMID 15546254
  40. Thymalfasin (thymosin-alpha 1) therapy in patients with chronic hepatitis B.Journal of gastroenterology and hepatology, 2004 · PMID 15641208
  41. Thymosin alpha(1) in combination with cytokines and chemotherapy for the treatment of cancer.International immunopharmacology, 2003 · PMID 12860169
  42. Thymosin alpha-1Am J Health Syst Pharm, 2001 · PMID 11381492
  43. Thymosin alpha 1 in the treatment of cancer: from basic research to clinical applicationInt J Immunopharmacol, 2000 · PMID 11137613
  44. Thymosin alpha1 treatment of chronic hepatitis B: results of a phase III multicentre, randomized, double-blind and placebo-controlled studyJ Viral Hepat, 1999 · PMID 10607256
  45. Efficacy of thymosin alpha1 in patients with chronic hepatitis B: a randomized, controlled trialHepatology, 1998 · PMID 9581695
  46. Thymosin alpha 1 antagonizes dexamethasone and CD3-induced apoptosis of CD4+ CD8+ thymocytes through the activation of cAMP and protein kinase C dependent second messenger pathways.Mechanisms of ageing and development, 1997 · PMID 9147362
  47. Thymosin alpha 1 protects liver and aorta from oxidative damage in atherosclerotic rabbits.Life sciences, 1996 · PMID 8809225
  48. Thymosin alpha 1 effects, in vitro, on lymphokine-activated killer cells from patients with primary immunodeficiencies: preliminary results.International journal of immunopharmacology, 1994 · PMID 7705963
  49. Thymosin alpha-1 as adjunct for conventional therapy of malignant tumors: a review.Cancer investigation, 1994 · PMID 7922706
  50. Thymosin alpha 1 and thymosin beta 4 modulate human colonic lamina propria lymphocyte function.Immunopharmacology, 1990 · PMID 2266003
  51. Thymosin alpha 1 modulates the expression of high affinity interleukin-2 receptors on normal human lymphocytes.International journal of immunopharmacology, 1990 · PMID 2303316
  52. A radioimmunoassay for thymosin alpha-1.Journal of immunological methods, 1986 · PMID 3701071
  53. Thymosin alpha 1-induced modulation of cellular responses and functional T-cell subsets in mice with experimental autoimmune thyroiditis.Cellular immunology, 1985 · PMID 3873993
  54. Thymosin alpha 1 restores NK-cell activity and prevents tumor progression in mice immunosuppressed by cytostatics or X-rays.Cancer immunology, immunotherapy : CII, 1983 · PMID 6553515
  55. Immunochemical studies on thymosin: radioimmunoassay of thymosin alpha 1.Journal of immunology (Baltimore, Md. : 1950), 1982 · PMID 7054279