Library / Peptides / Recovery & Healing / TB-500
Emerging evidence · Grade B

TB-500

TB-500 (Thymosin Beta-4 Fragment)
Evidence
Emerging
Route
Subcutaneous injection
Frequency
Loading: 2x weekly for 4-6 weeks; Maintenance: weekly or biweekly
Category
Recovery & Healing
TL;DR
TB-500 is a fragment of a naturally occurring healing protein called Thymosin Beta-4, which plays key roles in tissue repair, angiogenesis, and inflammation control. Animal studies and a handful of human trials with the full protein show genuine healing potential in tendons, heart tissue, and eye injuries. However, TB-500 itself (the fragment) has not been tested in human clinical trials, so its efficacy and safety in people are not established. It remains popular in athletic recovery communities as a research peptide.
Part 01 · How it works

Mechanism.

TB-500 is a synthetic peptide fragment corresponding to amino acids 17–23 of Thymosin Beta-4 (Tβ4), a naturally occurring 43-amino acid protein found in high concentrations in platelets, wound fluid, and most nucleated cells. Tβ4 regulates actin polymerization, promotes cell migration, angiogenesis, and tissue regeneration. TB-500 is widely used in performance and recovery communities for musculoskeletal healing but lacks human clinical trial data.

TB-500 can be thought of as a rapid-response team coordinator for injury sites. When tissue is damaged, actin reorganization is essential for cells to crawl to the wound and begin repair. TB-500 helps orchestrate this cellular movement while simultaneously calling in new blood vessel formation and immune de-escalation — it sets the stage for rapid, organized healing.

Mechanism · technical
TB-500's active fragment (LKKTETQ) is the actin-binding domain of Thymosin Beta-4 responsible for most of its regenerative biological activity. It sequesters G-actin monomers, regulating actin dynamics essential for cell migration and wound repair. It promotes upregulation of cell surface receptors including CXCR4, enhancing recruitment of progenitor cells to injury sites. It stimulates keratinocyte and endothelial cell migration, promotes VEGF-driven angiogenesis, and has potent inflammation-modulating properties. In cardiac tissue, Tβ4 and TB-500 promote cardiomyocyte survival and heart repair post-infarction.
Part 02 · Dosing & administration

How it's taken.

Values below describe how TB-500 has been administered in published trials and labeling. Provided for educational purposes only — this is not medical advice and not instructions for self-administration. Consult your healthcare provider before making any health decision.

Standard dose
2.5-5 mg loading; 2.5 mg maintenance
Subcutaneous injection · Loading: 2x weekly for 4-6 weeks; Maintenance: weekly or biweekly
Duration
Loading phase 4-6 weeks, then maintenance as needed

Active fragment of Thymosin Beta-4. Not FDA-approved. Often combined with BPC-157 for synergistic healing effects. Dosing based on published research protocols.

Need help with reconstitution?

Use the free peptide calculator for dilution, unit conversion, and injection volume.

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Part 03 · Safety

Side effects, rare serious events, who shouldn't.

Reported side effects
No significant adverse effects identified in animal studies. Human case reports and community use describe generally good tolerability. Fatigue, lethargy, or head rush reported by some users shortly after injection (possibly due to vasodilatory effects). Theoretical cancer risk from pro-angiogenic/pro-proliferative mechanisms is unquantified.
Absolute · do not use
×
Active malignancy or history of cancer (thymosin beta-4 may promote angiogenesis and cell migration)
×
Pregnancy or breastfeeding
×
Children under 18
×
Known hypersensitivity to TB-500, thymosin beta-4, or any component
Interactions
Anticoagulants (warfarin, heparin, DOACs)
TB-500 promotes wound healing and tissue repair which may alter coagulation dynamics; monitor INR
Moderate
Immunosuppressants
Thymosin beta-4 modulates immune and inflammatory responses; may interfere with immunosuppressive therapy
Moderate
NSAIDs
May have additive inflammation-modulating effects; generally favorable but monitor for reduced healing inflammation
Minor
Labs to monitor
CBC with Differential
Baseline and monthly
Monitor blood counts during tissue healing
CMP (Comprehensive Metabolic Panel)
Baseline and every 3 months
Liver and kidney function
CRP / ESR
Baseline and monthly
Track inflammatory markers during healing
Coagulation Panel (PT/INR)
Baseline
TB-500 affects angiogenesis and wound healing
Part 04 · Evidence

How strong is the evidence?

Scores derived from rating, indexed studies, regulatory status, and catalogued safety data for this peptide. Curated per-peptide scoring replaces this when available.

75
Grade B
Grade B. Signal is real but maturing. Treat results as directional until larger or independent replications land.
Clinical efficacy
Emerging signal across multiple indexed studies; effect sizes still firming up.
68
Study quality
4 indexed studies in our dataset. Designs vary — see Research log for per-study grades.
87
Regulatory clarity
FDA-approved for at least one indication.
90
Safety profile
Based on 4 documented contraindications, 3 interactions, 4 lab checkpoints.
84
Long-term data
Long-horizon data not yet available outside research settings.
48
Part 05 · Research log

Every study we cite.

Each study with its published finding and a plain-language note on limitations or funding.

01
2004
0
Thymosin Beta-4 promotes cardiac repair post-myocardial infarction
Tβ4 treatment in mice post-MI significantly improved cardiac function, reduced infarct size, promoted cardiomyocyte survival, and stimulated new blood vessel formation in peri-infarct tissue.
Mouse model. Full Tβ4 studied (not TB-500 fragment specifically). Translation to human cardiac recovery is speculative.
PMID 15163639 ↗
02
2010
0
Thymosin Beta-4 and tendon repair: enhanced biomechanical recovery
Tβ4 local delivery to surgically transected rat Achilles tendons significantly improved tensile strength, organization of collagen fibers, and cellular infiltration at 4 and 8 weeks post-surgery.
Rodent model. Full Tβ4 studied. TB-500 fragment assumed to retain the active domain but this is not directly confirmed in tendon-specific trials.
PMID 20148436 ↗
03
2010
0
Thymosin Beta-4 in corneal wound healing: clinical study
Tβ4 eye drops significantly accelerated corneal epithelial wound healing and reduced pain and inflammation after keratorefractive surgery in a randomized controlled study.
One of the few human RCTs of Tβ4. Topical eye drops — systemic conclusions cannot be drawn. Full Tβ4, not TB-500.
PMID 20019381 ↗
04
2012
0
The active domain of Thymosin Beta-4 (TB-500 equivalent) in wound healing
In vitro and animal wound healing studies confirmed that the 17–23 amino acid fragment (corresponding to TB-500) retains the major actin-binding and cell migratory properties of full-length Tβ4.
Largely mechanistic and animal data. Does not confirm equivalent clinical efficacy to full Tβ4.
PMID 22329660 ↗
Part 06 · Cost & access

Where you can get it.

Regulatory status
Not FDA-approved. Not approved in any country for human therapeutic use. Banned by WADA for use in competitive sports. Available as a research peptide. Full Thymosin Beta-4 (not the fragment) has been studied in FDA-registered clinical trials for cardiac and wound healing indications.
The Peptide Column takes no affiliate commission from any source.
Part 07 · Your appointment

Questions to bring.

01
Are there any human clinical trials of Thymosin Beta-4 or TB-500 underway that I might be eligible for?
02
Given TB-500's pro-angiogenic properties, is there any concern given my personal health history?
03
How does TB-500 compare to BPC-157 for my specific injury or recovery goal?
04
Is there an evidence-based alternative with completed human trials for my condition?