TB-500

Overview

TB-500 is a synthetic version of the active region of Thymosin Beta-4 (Tβ4), a 43-amino acid peptide naturally produced in the thymus gland and found in high concentrations in wound fluid, blood platelets, and other tissues. It plays a crucial role in tissue repair, cell migration, and anti-inflammatory processes.

While TB-500 specifically refers to the synthetic fragment, it's often used interchangeably with Thymosin Beta-4. The peptide has been studied in various clinical contexts including wound healing, cardiac repair, and ophthalmology.

Active Sequence Region: Ac-SDKP (N-terminal) and LKKTET (central region)

Mechanism of Action

TB-500/Thymosin Beta-4 exerts its effects through multiple pathways:

Actin Regulation

• Sequesters G-actin (monomeric actin)
• Promotes cell migration by regulating cytoskeleton
• Facilitates tissue remodeling

Cell Migration and Differentiation

• Promotes keratinocyte and endothelial cell migration
• Upregulates cell surface integrins
• Stimulates progenitor cell differentiation

Anti-inflammatory Effects

• Reduces inflammatory cytokines
• Decreases NF-κB activation
• May promote M2 macrophage phenotype

Angiogenesis

• Promotes blood vessel formation
• Upregulates VEGF in some contexts
• Enhances blood supply to damaged tissues

Cardiac Effects

• Activates cardiac progenitor cells (animal studies)
• May promote cardiomyocyte survival
• Studied in post-MI recovery models

Research Summary

Wound Healing Studies

Dermal Wounds

• Accelerated wound closure in diabetic mouse models
• Enhanced epithelialization
• Improved wound breaking strength

Corneal Wounds

• Phase 2 trials for dry eye (RegeneRx)
• Accelerated corneal healing
• RGN-259 (Tβ4) showed efficacy in neurotrophic keratopathy

Cardiac Studies (Animal)

Musculoskeletal (Animal)

• Improved tendon healing in rats
• Enhanced muscle regeneration after injury
• Reduced fibrosis in muscle damage models

Clinical Trials (Thymosin Beta-4)

• Phase 2 completed for dry eye syndrome
• Epidermolysis bullosa studies ongoing
• Cardiac applications in early trials

Veterinary Use

• Used in equine medicine for tendon injuries
• Some regulatory issues in horse racing

Pharmacokinetics

Note: Pharmacokinetics of synthetic TB-500 may differ from native Tβ4

Common Protocols

Note: TB-500 is not approved for human use. The following represents protocols discussed in research communities, not medical recommendations.

Research Community Protocols

Loading Phase (First 4-6 weeks):

• 2-2.5mg twice weekly
• Or 4-5mg once weekly
• Total weekly: 4-10mg

Maintenance Phase:

• 2mg once weekly
• Or 2mg twice monthly
• Duration: 4-8 weeks or longer

Reconstitution

• Lyophilized powder reconstituted with bacteriostatic water
• Common: 5mg vial + 1-2mL water
• Store reconstituted at 2-8°C
• Use within 8 weeks

Administration

Injection Routes

• Subcutaneous: Most common
• Intramuscular: Also used
• Both routes considered equivalent for systemic effects

Injection Guidelines

• No specific injection site requirements
• Systemic distribution means site less critical than BPC-157
• Rotate injection sites
• Use insulin syringes

Timing

• No established optimal timing
• Often dosed in evening
• Loading doses typically split (2x/week)

Side Effects

Reported in Studies

• Generally well-tolerated
• Mild injection site reactions
• No serious adverse events in clinical trials of Tβ4

Anecdotal Reports

• Temporary fatigue during loading
• Headache (rare)
• Mild flu-like symptoms (rare)
• Lethargy (uncommon)

Theoretical Concerns

• Angiogenesis and potential cancer implications
• Long-term effects unknown
• May affect tumor growth in cancer patients

Interactions

Theoretical Interactions

• Other angiogenic agents
• Immunomodulating drugs
• Growth factors

Contraindications (Theoretical)

• Active malignancy
• Pregnancy/nursing
• Autoimmune conditions (unstudied)

Community Insights

The following represents aggregated reports from online communities and should not be considered medical advice or verified claims.

Commonly Reported Experiences

• Accelerated recovery from muscle strains and tears
• Hair regrowth reported by some users
• Improved flexibility and reduced joint stiffness
• Often described as having "systemic" healing effects
• Some report improved endurance during loading phase

Common Applications

• Recovering from injuries
• Chronic tendinopathy
• Post-surgical healing
• Often combined with BPC-157

Practical Tips Shared

• Higher doses during initial loading commonly recommended
• Quality sourcing emphasized
• Patience needed - effects often take weeks to manifest
• May cause temporary tiredness during loading

Popular Stacks

• TB-500 + BPC-157: Most common combination
• TB-500 + GH secretagogues
• TB-500 + GHK-Cu for skin healing

Concerns Discussed

• Higher cost than BPC-157
• Less research than GLP-1 class
• Cancer concerns often raised
• Quality control issues with some sources

References

1. Goldstein AL, Kleinman HK. Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 2015;21(7):398-406. [PMID: 25919850]

2. Sosne G, et al. Thymosin beta 4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury. Exp Eye Res. 2002;74(2):293-9. [PMID: 11950239]

3. Bock-Marquette I, et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-72. [PMID: 15565145]

4. Hinkel R, et al. Thymosin β4 is an essential paracrine factor of embryonic endothelial progenitor cell-mediated cardioprotection. Circulation. 2008;117(17):2232-40. [PMID: 18427128]

5. Philp D, et al. Thymosin beta4 promotes angiogenesis, wound healing, and hair follicle development. Mech Ageing Dev. 2004;125(2):113-5. [PMID: 15037012]

6. RegeneRx Biopharmaceuticals. Clinical trials data for RGN-259 (Thymosin Beta 4).