watchAnecdotalNov 14, 2025
Influencer-driven demand
Public coverage connects TB-500 to the influencer and wellness-network spread of unapproved peptide use.
Associated Presshigh confidencemedia
Source TB 500
Thymosin Beta-4 Fragment · TB4-FRAG
Tissue RepairCategory 2Phase IIResearchSubQIM
Popular for:Tissue repair, wound healing, muscle recovery
1
Registered Trials
0
Trial Publications
16
PubMed References
Phase II
Evidence Level
Overview
TB-500 (Thymosin Beta-4 fragment, also called fequesetide) is a synthetic 7-amino-acid peptide derived from the active region of Thymosin Beta-4 (TB4), a naturally occurring 43-amino-acid peptide found in nearly all human cells. The short version: people usually care about it for tissue repair, wound healing, muscle recovery, but the strength of the evidence depends heavily on indication and study type.
TB-500 (Thymosin Beta-4 fragment, also called fequesetide) is a synthetic 7-amino-acid peptide derived from the active region of Thymosin Beta-4 (TB4), a naturally occurring 43-amino-acid peptide found in nearly all human cells. TB-500 is one of the most popular peptides for injury recovery and tissue repair.
**Originally developed for: **Wound healing and tissue repair research. TB4 was initially studied for its role in cardiac repair after myocardial infarction, corneal wound healing, and dermal wound repair. TB-500 was developed as a more stable, bioavailable synthetic fragment of the active region.
Research Snapshot
What the evidence says
Phase IITB 500 currently shows 1 registered trials from ClinicalTrials.gov, 0 PubMed trial publications (0 RCT-tagged), and 16 PubMed references matching the stored source query. Treat PubMed references as literature surface area, not a count of clinical trials.
Known vs uncertain
Known signals
- 1 registered trials are tracked from ClinicalTrials.gov intervention records.
- 0 PubMed clinical-trial publications are indexed.
- 0 PubMed randomized controlled trial publications are indexed.
- 16 PubMed references are tracked separately from trial counts and can include animal, in-vitro, review, mechanism, or clinical records.
Open questions
- Evidence strength may vary by indication, route, formulation, and population.
- Public anecdotes can highlight interest or concern but do not establish clinical efficacy.
- Regulatory status and compounding access can change independently from the research literature.
Mechanism of Action
TB-500 is an actin-binding peptide that promotes cell migration, proliferation, and differentiation.
Key Research Benefits
Primary Benefits:
Accelerated wound healing — TB4 in solution/gel form promoted wound healing in healthy, diabetic, and aged mice (Malinda et al., 2003)
Cardiac repair — Promotes cardiomyocyte survival and repair after myocardial infarction; promotes new blood vessel formation in damaged cardiac tissue (Bock-Marquette et al., 2004)
Anti-inflammatory — Reduces inflammatory cytokines; effective in models of arthritis and tissue inflammation
Soft tissue repair — Promotes tendon, ligament, and muscle healing through enhanced cell migration and extracellular matrix remodeling
Secondary/Emerging Benefits:
Hair growth — Stimulates hair follicle stem cells; community reports of improved hair thickness
Corneal healing — Promotes corneal wound repair; studied for dry eye and corneal injuries
Neuroprotection — Potential benefits for nerve regeneration and brain injury recovery
Liver protection — Hepatoprotective effects in animal models of fibrosis
Clinical Evidence Summary
Research Pipeline
Preclinical
Animal
Phase I
Phase II
Phase III
Approved
1
Registered Trials
0
Trial Publications
0
RCT Publications
16
PubMed References
ClinicalTrials.govPubMed ESearchExact-name queryChecked May 3, 2026
Registered trials are ClinicalTrials.gov intervention records. Trial publications are PubMed records tagged as clinical trials or randomized controlled trials. PubMed references are broader source-query matches and can include animal studies, in-vitro work, reviews, mechanism papers, and trial publications.
1
Registered trials
0
Trial publications
0
RCT publications
16
PubMed references
5
Reviews
0
Meta-analyses
Registered trials source
Jun 1, 2026
TB-500, TB 500
Uses curated ClinicalTrials.gov intervention aliases to avoid misleading registry matches.
View source- Malinda et al. (2003) — TB4 promoted accelerated wound healing in healthy, diabetic, and aged mice; the 7-amino-acid active fragment (TB-500) was identified as responsible for cell migration effects.
- Bock-Marquette et al. (2004) — TB4 promoted cardiomyocyte survival post-MI via activation of integrin-linked kinase (ILK); published in Nature.
- Goldstein et al. (2011) — Comprehensive review of TB4 as a multi-functional regenerative peptide, summarizing clinical applications.
- RegeneRx Biopharmaceuticals conducted Phase 2 clinical trials for TB4 eye drops (RGN-259) for dry eye syndrome with positive results.
> Clinical trial status: TB4 (the full peptide) has had some human trials, particularly for ophthalmic applications. TB-500 (the synthetic fragment) has very limited human trial data. Most evidence remains preclinical.
Key PubMed References
Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.
Review
Rahman OF, Lee SJ, Seeds WA · Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews · 2026
PMID: 41490200Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.
Review
Mayfield CK, Bolia IK, Feingold CL, et al. · The American journal of sports medicine · 2026
PMID: 41476424Therapeutic peptides in gerontology: mechanisms and applications for healthy aging.
Review
Mavrych V, Shypilova I, Bolgova O · Frontiers in aging · 2026
PMID: 42021992Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
Review
Mendias CL, Awan TM · Sports medicine (Auckland, N.Z.) · 2026
PMID: 41966639Comparative effects of dietary sodium butyrate and tributyrin on broiler chickens' performance, gene expression, intestinal histomorphometry, blood indices, and litter.
Review
Ismael E, Kamel S, Elleithy EMM, et al. · Scientific reports · 2025
PMID: 40681595Anecdotes & Sentiment
Public discussion, not clinical evidence
This section summarizes what people are talking about in public sources. It can be useful for spotting questions, hype cycles, and recurring concerns, but it is separate from the evidence sections above.
Side Effects & Safety
**Common Side Effects:** - Injection site redness/irritation - Mild headache - Temporary lethargy/fatigue - Head rush/lightheadedness shortly after injection **Rare but Serious Risks:** - Same angiogenesis concern as BPC-157 — theoretical risk of promoting tumor growth in individuals with existing cancer - Some early research suggested possible association with cancer progression, though more recent studies have challenged this; TB4 levels may be a marker rather than a cause > Contraindications: Avoid in individuals with active cancer or history of cancer.
Common Side Effects:
Injection site redness/irritation
Mild headache
Temporary lethargy/fatigue
Head rush/lightheadedness shortly after injection
Rare but Serious Risks:
Same angiogenesis concern as BPC-157 — theoretical risk of promoting tumor growth in individuals with existing cancer
Some early research suggested possible association with cancer progression, though more recent studies have challenged this; TB4 levels may be a marker rather than a cause
> Contraindications: Avoid in individuals with active cancer or history of cancer. Not recommended during pregnancy or breastfeeding. Use caution when combining with anticoagulants as TB-500 may affect platelet function.
Known Interactions
No curated interaction entry is live for TB 500 yet.
Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.
Comparison Pages
Frequently Asked Questions
Research Disclaimer
This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Regulatory status can vary by compound, formulation, indication, and jurisdiction. Check official labeling, registry records, and qualified professional guidance before making any health-related decision. The studies referenced are linked to their original PubMed sources for verification.