Peptide Reference · Healing & Recovery
TB-500
TB-500 is a synthetic analogue of Thymosin Beta-4 — a naturally occurring 43-amino-acid peptide studied for its roles in tissue repair, angiogenesis, and inflammatory regulation.
For research and educational purposes only · Not for human consumption
In Brief
TB-500 is the synthetic version of Thymosin Beta-4, a small protein the body produces naturally — in higher concentrations at sites of injury. Researchers are interested in it because it appears to speed up wound healing, reduce inflammation, and promote the formation of new blood vessels across a wide range of tissue types in animal models.
Unlike BPC-157, Thymosin Beta-4 has been investigated in some human clinical trials — primarily in cardiac repair and wound healing contexts. However, it is not approved for general human use and remains on the WADA prohibited list. The evidence base, while broader than many research peptides, still lacks large, independent replication.
Overview
TB-500 is the commercially used name for synthetic Thymosin Beta-4 (Tβ4), a 43-amino-acid peptide that occurs naturally in virtually all human and animal cells. The natural form is found in high concentrations in platelets and wound fluid, suggesting a physiological role in the early stages of tissue repair. It was first isolated from bovine thymus tissue in the 1960s and has been extensively studied since the 1990s.
The peptide’s primary molecular action involves sequestering G-actin — monomeric actin — which regulates how cells reorganise their internal scaffolding to migrate toward injury sites. This mechanism underlies many of its observed effects: faster cell migration, angiogenesis, and reduced local inflammation. TB-500 has been studied in cardiac repair, wound healing, corneal repair, and musculoskeletal recovery contexts, with a broader human trial base than most research peptides.
Administration Routes
Two routes are primarily used in TB-500 research contexts. Unlike BPC-157, oral delivery has not been meaningfully studied due to TB-500’s larger peptide size and susceptibility to digestive enzymes.
Subcutaneous (SC)
Injection into the subcutaneous fat layer, typically on the abdomen or flank. The most frequently used route in animal healing studies and the preferred route in informal research settings due to ease of administration.
Intramuscular (IM)
Injection directly into muscle tissue. Used in some musculoskeletal and cardiac repair studies. Provides faster systemic absorption than SC. Typically administered into the deltoid, thigh, or glute in research contexts.
Intravenous (IV)
Used exclusively in clinical trial settings for cardiac applications. Not applicable to informal research contexts. Mentioned here for completeness given its use in human trials for acute myocardial conditions.
Reconstitution Guide
TB-500 is supplied as a lyophilised powder and must be reconstituted before use. Standard peptide-handling practice applies.
Gather supplies
Bacteriostatic water (BAC water), alcohol swabs, a 1 mL insulin syringe, and the peptide vial. BAC water contains 0.9% benzyl alcohol which prevents bacterial growth across multiple uses.
Calculate your dilution
A common dilution for a 5 mg vial: add 2.5 mL BAC water → concentration of 2 mg/mL (2000 mcg/mL). Use the calculator below to determine exact volumes for your intended dose.
Add the water slowly
Wipe both vial tops with an alcohol swab. Draw the BAC water into the syringe. Insert the needle and angle it so the stream runs down the inside wall of the vial — do not shoot it directly onto the powder cake.
Mix gently
Once all water is added, swirl gently in a circular motion until fully dissolved. Do not shake or vortex — TB-500 is a larger peptide and mechanical agitation can accelerate degradation.
Store correctly
Reconstituted peptide: refrigerate at 2–8°C, away from light. Use within 4–6 weeks. Lyophilised powder: store frozen at −20°C long-term, or refrigerated if using within a few months. Label with reconstitution date.
Reconstitution Calculator
Enter your vial size, water volume, and intended dose to calculate the exact volume and syringe markings.
⚠ This calculator is a reference tool only. Verify all calculations independently before use. Not a substitute for professional guidance.
Cycling & Timing
No standardised human protocol exists. The following reflects patterns observed across preclinical studies and general research conventions for Thymosin Beta-4.
Common research uses
Published studies have examined TB-500 / Thymosin Beta-4 in the following contexts. None of these constitutes an approved therapeutic indication.
- Wound healing and skin repair — acceleration of dermal repair and re-epithelialisation in excisional wound models.
- Cardiac repair — reduction of infarct size and promotion of cardiomyocyte survival following experimental myocardial infarction; the basis for several human trials.
- Tendon and ligament healing — improved histological and biomechanical outcomes in rodent tendon injury models.
- Corneal repair — studied in dry eye disease and corneal injury models; the most advanced clinical application to date.
- Angiogenesis — promotion of new blood vessel formation at wound sites via upregulation of VEGF and associated signalling.
- Anti-inflammatory effects — downregulation of pro-inflammatory cytokines including TNF-α and IL-1β in tissue injury models.
Informally, TB-500 is used by athletes and biohackers for soft-tissue recovery. This use is unapproved and prohibited under WADA anti-doping regulations.
Mechanism of action
TB-500’s primary mechanism is well-characterised at the molecular level compared to many research peptides. Its central action involves sequestering G-actin, which has cascading effects on cell behaviour:
- Actin sequestration — Tβ4 binds G-actin (monomeric actin) through its LKKTET motif, preventing polymerisation into F-actin filaments. This free pool of unpolymerised actin is used to drive the lamellipodia of migrating cells toward injury sites.
- Cell migration — by modulating actin dynamics, TB-500 accelerates the migration of endothelial cells, keratinocytes, and macrophages to wound sites — a rate-limiting step in tissue repair.
- Angiogenesis — promotes sprouting angiogenesis by upregulating VEGF expression and supporting endothelial cell tube formation in vitro and in vivo.
- Anti-inflammatory modulation — downregulates NF-κB signalling and reduces production of pro-inflammatory cytokines, contributing to an environment more conducive to repair.
- Cardioprotection — in cardiac models, promotes survival of cardiomyocytes under ischaemic stress and supports recruitment of cardiac progenitor cells.
Unlike BPC-157, TB-500 has a clearly identified molecular target (G-actin via the LKKTET binding domain), making its mechanism more tractable to study. However, downstream effects in complex in vivo systems remain incompletely characterised.
Active compound & chemistry
Thymosin Beta-4 is a 43-amino-acid peptide with an approximate molecular weight of 4,964 Da and molecular formula C₂₁₂H₃₅₀N₅₆O₇₈S. It is the most abundant member of the beta-thymosin family in mammalian cells. The peptide contains a single methionine residue (Met-6) that can be oxidised under certain conditions, forming Thymosin Beta-4 sulfoxide — a naturally occurring variant with potentially distinct biological activity.
The key functional domain is the central actin-binding motif LKKTET (amino acids 17–23), which is responsible for G-actin sequestration. This region is conserved across species, suggesting evolutionary importance. The N-terminal and C-terminal regions contribute to overall structure and may modulate binding affinity. Look up the compound in PubChem for full structural data.
Evidence summary
TB-500 has a broader clinical evidence base than most research peptides, with some human trial data in cardiac and corneal applications. The preclinical literature is extensive and originates from multiple independent research groups — a meaningful distinction from some other research peptides.
Accelerated wound healing in excisional models
Multiple rodent studies have demonstrated that topical or systemic Thymosin Beta-4 accelerates re-epithelialisation of excisional wounds, with faster wound closure and improved collagen organisation compared with controls. The effect has been reproduced by multiple independent groups across different wound models.
Malinda KM et al. (1999) · FASEB J · View on PubMed →
Cardiac protection following myocardial infarction
In rodent myocardial infarction models, Thymosin Beta-4 reduced infarct size, improved left ventricular function, and promoted survival of cardiomyocytes at the infarct border zone. The peptide also appears to activate cardiac progenitor cells. These findings supported progression to human trials for post-infarct cardiac repair.
Bock-Marquette I et al. (2004) · Nature · View on PubMed →
Phase II trial in dry eye disease (RGN-259)
Under the development code RGN-259, a Thymosin Beta-4 ophthalmic solution was evaluated in two Phase II trials (ARISE-1 and ARISE-2) for neurotrophic keratopathy and dry eye disease. The trials reported improvements in corneal staining and symptom scores compared with placebo, representing the most advanced human clinical data for any Thymosin Beta-4 application.
Sosne G et al. (2018) · Cornea · View on PubMed →
Tendon healing in animal models
Studies in horse and rodent models have found that Thymosin Beta-4 promotes tendon fibroblast migration and collagen synthesis following injury. Equine studies are particularly cited in the research peptide community given their translational relevance and the clinical application of Tβ4 in veterinary medicine — one of few contexts where it is legally used.
Genovese RL et al. (2007) · Equine Vet J · View on PubMed →
Warnings & cautions
- Not approved for human use in the United States, European Union, United Kingdom, Canada, or Australia for any systemic application. Veterinary use is permitted in some jurisdictions.
- Banned in competitive sport by the World Anti-Doping Agency (WADA) under S0 (Non-Approved Substances).
- Angiogenic effects carry theoretical oncological risk. Any peptide that promotes new blood vessel formation may theoretically support tumour vascularisation. This concern applies particularly to individuals with active or recent cancer history.
- Methionine oxidation. The Met-6 residue in TB-500 is susceptible to oxidation during improper storage or reconstitution. Oxidised Tβ4 sulfoxide may have altered biological activity.
- Source quality is uncontrolled. Products sold for “research” are not regulated and may contain incorrect doses, contaminants, or misidentified compounds.
References
- Malinda KM, Sidhu GS, Mani H, Banaudha K, Maheshwari RK, Goldstein AL, Kleinman HK. (1999). Thymosin beta4 accelerates wound healing. FASEB Journal. PubMed
- Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. (2004). Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. PubMed
- Sosne G, Qiu P, Kurpakus-Wheater M. (2018). Thymosin beta-4 and the eye: the journey from bench to bedside. Cornea. PubMed
- Genovese RL, Hennessy PW, Horspool LJI. (2007). Treatment of superficial digital flexor tendon injuries in horses with intralesional thymosin beta 4. Equine Veterinary Journal. PubMed
- Smart N, Risebro CA, Melville AAD, Moses K, Schwartz RJ, Bhatt DL, Riley PR. (2007). Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. Nature. PubMed
Reference links resolve to PubMed search queries. Verify the specific PMID before citing.
Important: This page is educational and reference-only. TB-500 is not approved for human use in most jurisdictions and is prohibited in competitive sport. Nothing here is medical advice. Any research must comply with applicable laws and institutional review requirements. Consult a qualified healthcare professional before making decisions about your health.