What Is Thymosin Beta-4? Benefits, Research & Safety
A 43-amino acid peptide naturally present in all cells, fundamental to tissue repair, cell migration, and regeneration processes throughout the body.
UK summary: Not a licensed UK medicine. The full-length parent protein of TB-500; investigated in some early human cardiac and wound-healing trials. Treated by WADA as prohibited under the growth-factors category.
Quick Facts
Overview
Thymosin Beta-4 — evidence and risk at a glance
Twenty standard modules scored against the Peptide Authority evidence grading methodology. Missing modules indicate the field has not yet been characterised editorially — treat absences as uncertainty rather than reassurance.
01Evidence snapshot
Not a licensed UK medicine. The full-length parent protein of TB-500; investigated in some early human cardiac and wound-healing trials. Treated by WADA as prohibited under the growth-factors category.
02Human evidence grade
03Preclinical evidence grade
04Regulatory status
- UK: Not licensed for human therapeutic use. Research compound.
- EU: Orphan drug designation for some indications. Not generally approved.
- Notes: Thymosin Beta-4 has received orphan drug designation for certain conditions but remains largely in clinical development. RegeneRx has advanced several Tβ4-based products through clinical trials.
05Approved medical uses
None in the UK or EU as a finished medicine. (Or: not yet documented; treat as absence rather than approval.)
06Unapproved / promotional claims
- Faster healing of any injury.
- Heart-attack recovery accelerator.
- Safe for daily long-term injection.
07Common internet claims
- Marketed alongside TB-500 as the 'full' thymosin beta-4 product.
- Sold by online retailers as research-only injectable.
- Promoted by athletes despite WADA prohibition.
08Claim vs evidence
| Claim | Evidence | Human evidence? | Regulatory concern | Safer wording |
|---|---|---|---|---|
| “Repairs cardiac tissue after heart attack” | C | Limited | High | Early-phase human cardiac trials investigated Tβ4 for myocardial repair; outcomes data did not produce a licensed product. |
| “Heals injuries faster than TB-500” | E | No | High | No head-to-head human trials of full Tβ4 vs the commercial TB-500 fragment exist. |
| “Safe for long-term use” | E | No | High | Long-term human safety is not established. |
| “Available from research suppliers — same molecule as clinic-grade” | E | No | High | Grey-market protein supply lacks identity / purity verification. |
09Safety uncertainty score
Limited human safety data; meaningful uncertainty about rare or long-term effects.
10Known adverse signals
- Limited human safety data outside small Phase 2 cardiac trials.
- WADA S2 prohibited.
- Injection-site reactions.
11Drug-interaction uncertainty
Interaction picture sparse; meaningful uncertainty when combined with other medicines.
12Anti-doping status
13UK legal position
Not licensed for human therapeutic use. Research compound.
14EU legal position
Orphan drug designation for some indications. Not generally approved.
15What this page cannot tell you
- Whether a UK-purchased vial contains TB4 at the labelled concentration.
- Long-term oncologic risk from sustained TB4 elevation.
16Last reviewed
17Citation quality score
18Research gaps
- Phase 3 trials for any indication absent.
- Long-term healthy-adult safety unstudied.
19Safer alternatives / established care pathways
- NHS physiotherapy + sports-medicine pathway for tissue injury.
- NHS cardiology pathway for cardiac concerns.
20Doctor discussion prompts
Questions to ask a qualified clinician
These are starter questions you can adapt for a GP, specialist, pharmacist, or anti-doping advisor. The aim is to help you have a better-informed conversation — not to replace one.
- Is Thymosin Beta-4 a licensed UK medicine?
- What human evidence exists beyond the early-phase cardiac trials?
- If I'm an athlete, what is the WADA position on Tβ4 and TB-500?
- What licensed treatments exist for my underlying injury or cardiac concern?
Discovery & History
Mechanism of Action
Researched Benefits
Based on preclinical and clinical research findings:
- 1Accelerated wound healing with improved tissue quality
- 2Enhanced cardiac repair and regeneration following injury
- 3Improved angiogenesis and blood vessel formation
- 4Reduced inflammation and scarring
- 5Potential benefits for dry eye syndrome
- 6Possible neuroprotective effects in brain injury
- 7Support for hair follicle regeneration
- 8Enhanced stem cell activation and tissue regeneration
Claim vs Evidence
How popular claims about Thymosin Beta-4 stack up against the current research, graded using our public evidence grading methodology.
| Claim | Evidence | Human evidence? | Regulatory concern | Safer wording |
|---|---|---|---|---|
| “Repairs cardiac tissue after heart attack” | C | Limited | High | Early-phase human cardiac trials investigated Tβ4 for myocardial repair; outcomes data did not produce a licensed product. |
| “Heals injuries faster than TB-500” | E | No | High | No head-to-head human trials of full Tβ4 vs the commercial TB-500 fragment exist. |
| “Safe for long-term use” | E | No | High | Long-term human safety is not established. |
| “Available from research suppliers — same molecule as clinic-grade” | E | No | High | Grey-market protein supply lacks identity / purity verification. |
Theoretical Dosing & Protocols
| Theoretical Dosage | Variable depending on application and formulation; clinical trials have used various dosing regimens |
| Frequency | Depends on indication and delivery method |
| Duration | Variable by application |
| Notes | Thymosin Beta-4 has been studied in clinical trials for specific indications. Protocols vary significantly. Any use should be under medical supervision and preferably within clinical research frameworks. |
Administration Routes
Routes studied in research settings (educational only):
- Subcutaneous injection
- Intramuscular injection
- Topical application (eye drops for dry eye)
- Intravenous administration (certain clinical settings)
| Half-Life | Stability |
|---|---|
| Relatively short plasma half-life; effects may persist longer due to intracellular mechanisms | Stable when properly stored; lyophilised forms preferred for long-term storage |
Safety Profile & Known Risks
Commonly Reported Side Effects
- Injection site reactions
- Temporary fatigue or flu-like symptoms
- Mild headache in some cases
Rare Risks & Concerns
- Unknown long-term effects from exogenous administration
- Theoretical concerns regarding tumour promotion
- Possible cardiovascular effects
Contraindications
- Active malignancy
- Pregnancy and breastfeeding
- Certain cardiovascular conditions
- Children (limited safety data)
UK & EU Regulatory Context
🇬🇧 United Kingdom
Not licensed for human therapeutic use. Research compound.
🇪🇺 European Union
Orphan drug designation for some indications. Not generally approved.
Clinical Studies Summary
Thymosin β4 Activates Integrin-Linked Kinase and Promotes Cardiac Cell Migration and Survival
Demonstrated Tβ4's cardioprotective mechanisms and potential for cardiac regeneration.
Thymosin beta 4: An emerging therapeutic candidate for kidney diseases.
Finally, translational opportunities are appraised with attention to pharmacokinetics, peptide stability and delivery strategies. Key challenges moving forward include validating efficacy in additional clinically relevant models, overcoming peptide instability and completing comprehensive safety assessments.
Thymosin beta-4 denotes new directions towards developing prosperous anti-aging regenerative therapies.
We discovered TB4 is capable of epicardial progenitor activation, and revealed the effect is independent of hypoxic injury. By observing the above results, we believe, further discoveries and consequential postnatal administration of developmentally relevant candidate molecules such as TB4 may likely result in reversing aging processes and accelerate organ regeneration in the human body.
Tβ4-Ac-SDKP pathway: Any relevance for the cardiovascular system?
En dépit de la localisation et de la caractérisation des sites de liaison de l’Ac-SDKP dans le myocarde, d’autres études seraient nécessaires pour caractériser entièrement et cloner les récepteurs de l’Ac-SDKP.
Sources of variability in quantifying circulating thymosin beta-4: literature review and recommendations.
We further highlight three factors that may confound TB4 clinical measurements and should be considered in future study design: 1) residual platelets remaining in suspension after centrifugation, 2) TB4 release following ex vivo platelet activation, and 3) specificity of assays towards posttranslational modifications.
Thymosin beta 4 regulation of actin in sepsis.
Given that Thymosin Beta 4 inhibits the polymerization of F-actin, it is possible that Thymosin Beta 4 decreases mortality in sepsis via the regulation of actin as well as its other anti-inflammatory properties and should be further pursued as a clinical trial in humans with sepsis.
Registered Trials & Regulatory Status
5 of 9 completed trials have never posted results. Unreported trials are not neutral: results that go unpublished are more often negative ones.
Recombinant Human Thymosin Beta 4 for Injection(NL005) for Acute Myocardial Infarction
Status: Not Yet Recruiting · 189 participants · Beijing Northland Biotech. Co., Ltd.
Conditions: Acute Myocardial Infarction (AMI), Acute Myocardial Infarction of Anterior Wall, Acute Myocardial Infarction With ST Elevation
TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable ASCVD
Status: Recruiting · 80 participants · Hudson Biotech
Conditions: Atherosclerotic Cardiovascular Diseases, Endothelial Dysfunction
Efficacy and Safety Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction
Status: Completed · 90 participants · Beijing Northland Biotech. Co., Ltd.
Conditions: Acute Myocardial Infarction
Safety and Efficacy Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction.Infarction
Status: Completed · 62 participants · Beijing Northland Biotech. Co., Ltd.
Conditions: Acute Myocardial Infarction
A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Myocardial Infarction
Status: Withdrawn · RegeneRx Biopharmaceuticals, Inc.
Conditions: Acute Myocardial Infarction, ST Elevation Myocardial Infarction, STEMI
A Phase 1b Study of Thymosin Beta 4 in Healthy Volunteers
Status: Completed · 30 participants · Beijing Northland Biotech. Co., Ltd.
Conditions: Healthy
A Phase 1a Study of Thymosin Beta 4 in Healthy Volunteers
Status: Completed · 54 participants · Beijing Northland Biotech. Co., Ltd.
Conditions: Healthy
Slow-release Tb4 Collagen and Chitosan Porous Sponge Scaffolds Skin Substitute Treatment is Difficult to Heal Wounds
Status: Completed · 20 participants · Chinese PLA General Hospital
Conditions: Wounds
Safety and Efficacy of Thymosin Beta 4 Ophthalmic Solution in Patients With Dry Eye
Status: Completed · 72 participants · ReGenTree, LLC
Conditions: Dry Eye Syndrome, Dry Eye
Comparative Study of Thymosin Beta 4 Eye Drops vs. Vehicle in the Treatment of Severe Dry Eye
Status: Completed · 9 participants · Michigan Cornea Consultants, PC
Conditions: Dry Eye, Sjogren's Syndrome, Graft vs. Host Disease
A Phase 1 Safety Study of the Intravenous Administration of Thymosin Beta in Healthy Volunteers
Status: Withdrawn · RegeneRx Biopharmaceuticals, Inc.
Conditions: Myocardial Infarction, Myocardial Ischemia
A Phase 2 Study of the Safety and Efficacy of Thymosin Beta 4 for Treating Corneal Wounds
Status: Terminated · 12 participants · ReGenTree, LLC
Conditions: Diabetes
Adverse event reports (FDA FAERS)
Not applicable: no licensed product contains this peptide, so it is not reported through FAERS. This is an absence of surveillance, not evidence of safety.
Source: ClinicalTrials.gov and openFDA. Updated automatically.
Looking for Thymosin Beta-4?
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View at SupplierFrequently Asked Questions
Questions to ask a qualified clinician about Thymosin Beta-4
These are starter questions you can adapt for a GP, specialist, pharmacist, or anti-doping advisor. The aim is to help you have a better-informed conversation — not to replace one.
- Is Thymosin Beta-4 a licensed UK medicine?
- What human evidence exists beyond the early-phase cardiac trials?
- If I'm an athlete, what is the WADA position on Tβ4 and TB-500?
- What licensed treatments exist for my underlying injury or cardiac concern?
UK regulatory & safety context
Peptide Comparisons
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