What is TB-500 used for in research?

TB-500 is primarily researched for its tissue healing and regenerative properties. Studies have investigated its potential in wound healing, muscle repair, cardiac regeneration, and recovery from various injuries. It promotes cell migration and new blood vessel formation.

While preclinical research has shown a generally favourable safety profile, comprehensive human safety data is limited. The long-term effects are unknown, and it is not approved for human use. Any use should be discussed with a qualified healthcare professional.

How does TB-500 differ from Thymosin Beta-4?

TB-500 is a synthetic peptide that replicates the active region of the full Thymosin Beta-4 protein. While the full Tβ4 molecule has 43 amino acids, TB-500 contains the key active sequence responsible for the protein's tissue-repair properties.

What is the difference between TB-500 and BPC-157?

Both are researched for healing properties but work through different mechanisms. TB-500 primarily promotes cell migration via actin upregulation and stimulates angiogenesis. BPC-157 works through growth factor modulation and nitric oxide system interaction. They are sometimes combined in research settings.

Is TB-500 banned in sports?

Yes, TB-500 (Thymosin Beta-4) is prohibited by WADA (World Anti-Doping Agency) and is banned in most competitive sports. Athletes should not use this peptide as it may result in sanctions.

Does TB-500 have human clinical trials?

Human clinical trials for Thymosin Beta-4 have been conducted, particularly for wound healing and cardiac applications. However, TB-500 specifically has limited human trial data. The parent compound Tβ4 has reached Phase II clinical trials for some indications.

Fact-checked by the Peptide Authority Editorial Board · Last reviewed: 2 February 2026

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Healing & Recovery•Updated 2026-02-02•7 min read

What Is TB-500? Benefits, Research & Safety

A synthetic version of the naturally occurring peptide Thymosin Beta-4, extensively researched for its roles in tissue repair, cell migration, and angiogenesis.

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Also known as:

Thymosin Beta-4 Fragment

TB4-Frag

Tβ4

DAnimal/cell evidence onlyUK: Sold as 'research only' (UK)WADA: Prohibited in sport

UK summary: Not a licensed UK medicine. The active fragment of Thymosin Beta-4, studied largely in preclinical animal models. Treated by WADA as prohibited; sold by some online retailers as 'research only'.

Quick Facts

Overview

TB-500 is a synthetic peptide that replicates the active region of Thymosin Beta-4 (Tβ4), a 43-amino acid protein that is naturally present in virtually all human and animal cells. Thymosin Beta-4 is one of the most abundant intracellular proteins and plays fundamental roles in tissue repair, cell migration, and the formation of new blood vessels. The peptide sequence of TB-500 corresponds to the active site of Thymosin Beta-4, specifically the region responsible for its actin-binding and cell-migration-promoting properties. This makes TB-500 particularly interesting to researchers studying wound healing, tissue regeneration, and recovery from injury. TB-500's primary mechanism involves the upregulation of actin, a protein that forms part of the cell's cytoskeleton and is essential for cell motility. By promoting actin production and organisation, TB-500 may enhance the ability of cells to migrate to sites of injury and participate in the healing process. Research has explored TB-500's potential applications in various contexts including muscle and tendon injuries, cardiac repair following ischemic events, wound healing, and neurological recovery. The peptide has generated particular interest in veterinary medicine and sports medicine research. TB-500 is classified as a research peptide and is not approved for human therapeutic use. It is prohibited by WADA in competitive sports.

Evidence standards summary

TB-500 — 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

DAnimal/cell evidence onlyOverall grade against our evidence grading methodology.

Not a licensed UK medicine. The active fragment of Thymosin Beta-4, studied largely in preclinical animal models. Treated by WADA as prohibited; sold by some online retailers as 'research only'.

02Human evidence grade

ETheoretical / insufficientStrength of evidence from published human trials.

03Preclinical evidence grade

CLimited human evidenceAnimal-model and in-vitro evidence quality.

04Regulatory status

UK: Not licensed for human therapeutic use. Available only as a research chemical. Prohibited in competitive sports.
EU: Not authorised by EMA for human use. Research compound status in member states.
Notes: TB-500 is prohibited by WADA and banned in most competitive sports organisations. It is not approved by the FDA, MHRA, or EMA for human medical use. Any use is at individual risk and should be under medical supervision.

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

Heals tendons and ligaments faster than physio
Repairs muscle tears, joint damage, and cardiac tissue
‘Gold-standard healing stack’ with BPC-157
Anti-inflammatory and recovery aid for athletes

07Common internet claims

Stack with BPC-157 for ‘injury immunity’
Heals injuries that physio can't fix
Safe based on animal data

08Claim vs evidence

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“Accelerates muscle and tendon recovery”	D	No	High	Animal-model evidence suggests effects on cell migration and tissue repair; human evidence for the marketed fragment is lacking.
“Heals chronic injuries that physio can't”	E	No	High	There are no UK-approved indications. Robust comparison with conventional rehab does not exist in the literature.
“Safe for long-term use”	E	No	High	Long-term human safety is not established.
“Permitted for non-tested athletes”	E	No	High	TB-500 is prohibited under WADA at all times. Risk applies even where no testing is currently planned.

09Safety uncertainty score

High

Limited human safety data; meaningful uncertainty about rare or long-term effects.

10Known adverse signals

Long-term human safety not characterised
Theoretical concerns from actin-modulating mechanism
Sterility / identity risk from grey-market supply
WADA S2 strict-liability risk for athletes

11Drug-interaction uncertainty

High

Interaction picture sparse; meaningful uncertainty when combined with other medicines.

12Anti-doping status

WADA: Prohibited in sportWADA strict-liability framing applies.

13UK legal position

UK: Sold as 'research only' (UK)

Not licensed for human therapeutic use. Available only as a research chemical. Prohibited in competitive sports.

Read the full UK legal guide → Are peptides legal in the UK?

14EU legal position

Not authorised by EMA for human use. Research compound status in member states.

15What this page cannot tell you

Whether TB-500 is safe for you as an individual.
What dose or frequency is appropriate for any human condition.
Whether the product you might obtain actually contains TB-500.
Long-term effects of repeated thymosin beta-4 fragment exposure.

16Last reviewed

Last reviewed: 2 February 2026

Next review due: 2 February 2027

Spotted an error or something out of date? Send a correction.

17Citation quality score

CLimited human evidenceQuality of the sources we cite, graded against the evidence grading methodology.

18Research gaps

No completed UK / EU human RCTs for any tissue-repair indication.
Pharmacokinetics in humans poorly characterised.
Long-term safety unknown.
Combination studies with BPC-157 in humans absent.

19Safer alternatives / established care pathways

Evidence-based physiotherapy for tendon, ligament, and muscle injury.
NICE-recommended licensed treatments for the specific condition.
Specialist sports-medicine assessment for recurring injury patterns.

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 TB-500 a licensed UK medicine?
What human evidence exists beyond preclinical animal data?
What is the WADA / UKAD position if I compete in sport?
Are there licensed treatments for my underlying injury?
If I'm offered TB-500 by a clinic, what regulator covers that clinic?

Discovery & History

Thymosin Beta-4, the parent molecule of TB-500, was first isolated from the thymus gland in 1966 by Allan Goldstein and colleagues at the Albert Einstein College of Medicine in New York. Initially, research focused on its immunological properties, as the thymus plays a crucial role in immune system development. Throughout the 1970s and 1980s, further research revealed that Thymosin Beta-4 was not limited to immune tissues but was in fact present in virtually all cell types throughout the body. This ubiquitous distribution suggested functions beyond immune regulation. The discovery that Thymosin Beta-4 was a major actin-sequestering protein came in the 1990s, fundamentally changing understanding of its biological roles. Researchers found that Tβ4 binds to monomeric actin (G-actin) and prevents its polymerisation, thereby regulating the dynamics of the cellular cytoskeleton. Subsequent research identified the specific regions of Thymosin Beta-4 responsible for its various biological activities. The synthetic peptide TB-500 was developed to replicate the most active region of the molecule for research purposes. Thymosin Beta-4 gained attention in veterinary medicine, particularly in horse racing, where it was used (controversially) to promote recovery from injuries. This led to increased scrutiny and its eventual prohibition in competitive sports. Research continues to explore the therapeutic potential of Thymosin Beta-4 and related peptides, with clinical trials investigating applications in wound healing, cardiac repair, and other regenerative medicine applications.

Mechanism of Action

TB-500 exerts its biological effects through several key molecular mechanisms that work together to promote tissue repair and regeneration: **Actin Regulation and Cell Migration** The primary mechanism of TB-500 involves its interaction with actin, a protein fundamental to cell structure and movement. TB-500 binds to monomeric actin (G-actin) and promotes the formation of filamentous actin (F-actin), which is essential for cell motility. By upregulating actin production and organisation, TB-500 enhances the ability of various cell types—including stem cells, fibroblasts, and endothelial cells—to migrate to sites of injury. **Angiogenesis Promotion** TB-500 stimulates the formation of new blood vessels (angiogenesis) by promoting endothelial cell migration and capillary-like structure formation. Improved vascularisation at injury sites enhances the delivery of oxygen, nutrients, and reparative cells essential for tissue healing. This angiogenic effect is mediated partly through increased VEGF receptor expression. **Anti-Inflammatory Properties** Research suggests that TB-500 possesses anti-inflammatory effects, potentially through modulation of inflammatory cytokine production. By reducing excessive inflammation at injury sites, the peptide may help prevent secondary tissue damage and promote a healing environment. **Cell Differentiation Effects** Studies indicate that TB-500 may influence the differentiation of progenitor cells and stem cells toward specific tissue lineages. This effect may be particularly relevant for cardiac repair, where the peptide has shown potential to promote cardiomyocyte regeneration. **Matrix Metalloproteinase Regulation** TB-500 appears to modulate the activity of matrix metalloproteinases (MMPs), enzymes involved in the breakdown and remodelling of extracellular matrix during tissue repair. Proper regulation of MMPs is essential for organised healing rather than scar tissue formation. **Gene Expression Modulation** Research has demonstrated that TB-500 affects the expression of numerous genes involved in tissue repair, including those related to cell survival, inflammation, and matrix remodelling.

Researched Benefits

Based on preclinical and clinical research findings:

1
Enhanced wound healing and tissue regeneration in multiple animal models
2
Improved muscle repair and reduced recovery time following injury
3
Potential cardiac tissue regeneration following ischemic injury
4
Anti-inflammatory effects that may reduce secondary tissue damage
5
Accelerated tendon and ligament healing with improved tissue quality
6
Enhanced hair follicle growth in dermal wound healing models
7
Potential neuroprotective effects in models of central nervous system injury
8
Improved blood vessel formation (angiogenesis) at injury sites

Claim vs Evidence

How popular claims about TB-500 stack up against the current research, graded using our public evidence grading methodology.

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“Accelerates muscle and tendon recovery”	D	No	High	Animal-model evidence suggests effects on cell migration and tissue repair; human evidence for the marketed fragment is lacking.
“Heals chronic injuries that physio can't”	E	No	High	There are no UK-approved indications. Robust comparison with conventional rehab does not exist in the literature.
“Safe for long-term use”	E	No	High	Long-term human safety is not established.
“Permitted for non-tested athletes”	E	No	High	TB-500 is prohibited under WADA at all times. Risk applies even where no testing is currently planned.

Theoretical Dosing & Protocols

⚠️ Educational Only: The following information is derived from research literature and is not a prescription or recommendation. No standardised human dosing exists. Always consult a qualified healthcare professional.

Theoretical Dosage	2-2.5 mg per administration (based on research protocols in literature)
Frequency	Twice weekly during initial phase, then weekly for maintenance
Duration	4-8 weeks depending on research application and objectives
Notes	These are theoretical protocols extrapolated from research data. No approved human dosing exists. TB-500 is typically administered via subcutaneous or intramuscular injection in research settings. Due to its systemic distribution, injection site is less critical than with some other peptides. Consult a healthcare professional before any use.

Administration Routes

Routes studied in research settings (educational only):

Subcutaneous injection (most common in research)
Intramuscular injection (also frequently studied)

Half-Life	Stability
Approximately 2-3 days, allowing for less frequent administration than many peptides	Relatively stable when lyophilised; should be stored at -20°C for long-term preservation; reconstituted solutions should be refrigerated and used within recommended timeframes

Safety Profile & Known Risks

Commonly Reported Side Effects

Injection site reactions including redness, swelling, or temporary discomfort
Temporary fatigue or lethargy reported by some users
Head rush or flushing immediately following injection
Temporary flu-like symptoms in some cases

Rare Risks & Concerns

Unknown long-term effects in humans due to limited clinical data
Theoretical concerns regarding effects on cancer growth (promotes cell migration)
Potential cardiovascular effects requiring further investigation
Possible immune system effects given thymosin origin

Contraindications

Active cancer or history of malignancy (promotes angiogenesis and cell migration)
Pregnancy and breastfeeding (no safety data available)
Cardiovascular conditions (effects not fully characterised)
Children and adolescents (no paediatric safety data)
Immune system disorders (potential for immune modulation)

UK & EU Regulatory Context

🇬🇧 United Kingdom

Not licensed for human therapeutic use. Available only as a research chemical. Prohibited in competitive sports.

🇪🇺 European Union

Not authorised by EMA for human use. Research compound status in member states.

TB-500 is prohibited by WADA and banned in most competitive sports organisations. It is not approved by the FDA, MHRA, or EMA for human medical use. Any use is at individual risk and should be under medical supervision.

Clinical Studies Summary

De novo cardiomyocytes from within the activated adult heart after injury.

Research demonstrating that Thymosin Beta-4 activates resident cardiac progenitor cells and promotes cardiomyocyte regeneration following myocardial infarction in animal models.

Nature. 2011View on PubMed

Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.

While peptide therapy may possess significant therapeutic and regenerative potential, it is critical that orthopaedic and sports medicine providers understand the current lack of evidence to support the clinical use of these peptides. Importantly, information regarding the indications, dosing, frequency, and duration of treatment remains unknown.

Am J Sports Med. 2026View on PubMed

Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls.

) and non-peptidic (selective androgen receptor modulators, hypoxia-inducible factor stabilizers, siRNA, S-107 and ARM036/aladorian, etc. ) as well as inorganic (cobalt) nature are considered and discussed in terms of specific requirements originating from physicochemical properties, concentration levels, metabolism, and their amenability for chromatographic-mass spectrometric or alternative detection methods.

J Pharm Biomed Anal. 2014View on PubMed

Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro.

The study provides a valuable tool for quantifying TB-500 and its metabolites, contributing to the understanding of metabolism and potential therapeutic applications. Our results also suggest that the previously reported wound-healing activity of TB-500 in literature may be due to its metabolite Ac-LKKTE rather than the parent form.

J Chromatogr B Analyt Technol Biomed Life Sci. 2024View on PubMed

Adsorption effects of the doping relevant peptides Insulin Lispro, Synachten, TB-500 and GHRP 5.

Our experiments showed that choosing expensive consumables with low-bind characteristics is not beneficial in all cases. A careful selection of the consumables based on the evaluation of the physico/chemical features of the peptide is recommended.

Anal Biochem. 2017View on PubMed

Solid-phase extraction of small biologically active peptides on cartridges and microelution 96-well plates from human urine.

The use of microelution plates decreases consumption of solvents and allows processing of up to 96 samples simultaneously. Cartridge SPE with manual рН adjustment remains the best option for confirmation.

Drug Test Anal. 2016View on PubMed

Registered Trials & Regulatory Status

Registered trials

Currently recruiting

Furthest phase

Phase 2

Approved product

TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable ASCVD

PHASE1/PHASE2

Status: Recruiting · 80 participants · Hudson Biotech

Conditions: Atherosclerotic Cardiovascular Diseases, Endothelial Dysfunction

No results postedNCT07487363

A Phase 2 Study of the Safety and Efficacy of Thymosin Beta 4 for Treating Corneal Wounds

PHASE2

Status: Terminated · 12 participants · ReGenTree, LLC

Conditions: Diabetes

Results postedNCT00598871

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.

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Frequently Asked Questions

Questions to ask a qualified clinician about TB-500