TB-500
Thymosin Beta-4 Fragment
TB-500 is a peptide people usually talk about for Chronic non-healing wounds and Surgical wound healing. It is still in the FDA review process, so people are watching both the research and the access question closely.
Why does this matter?
TB-500 matters because a lot of people hear about it online without a clear sense of what it may actually help with. This page gives you the plain-English version first, then shows where the research is strongest, what is still uncertain, and where the peptide stands in the FDA review process.
Molecular weight
Not specified in the source research
Molecular formula
Not specified in the source research
Amino acid count
17
Review date
July 23-24, 2026
Sequence / structure
Linear peptide fragment
Other names
TB-500, Thymosin Beta-4 (Tβ4), TB4, Tβ4, Thymosin β4, RGN-259 (ophthalmic formulation by RegeneRx)
Status
Under FDA review for wound healing
TB-500 is a recovery peptide built from the most active portion of Thymosin Beta-4, one of the body’s core repair proteins. People usually reach for it in conversations about injury recovery, wound healing, flexibility, and getting damaged tissue to rebuild more smoothly after heavy stress. It is also interesting beyond sports because the same repair signals have shown potential in heart tissue, connective tissue, and broader inflammation control.
The quick version before the deep dive
- •People usually talk about TB-500 for Chronic non-healing wounds and Surgical wound healing.
- •Surgical wound healing.
- •Binds G-actin monomers, regulating cytoskeletal dynamics for cell migration.
- •Helps promote migration of endothelial cells, keratinocytes, and stem cells to injury sites.
Deep Dive: Mechanism of Action +
Actin Sequestration — Binds G-actin monomers, regulating cytoskeletal dynamics for cell migration
Cell Migration — Promotes migration of endothelial cells, keratinocytes, and stem cells to injury sites
Angiogenesis — Stimulates new blood vessel formation in damaged tissue
Anti-inflammatory — Reduces pro-inflammatory cytokines, decreases neutrophil infiltration
Matrix Metalloproteinase Regulation — Modulates MMP activity for tissue remodeling
Stem Cell Recruitment — Activates cardiac progenitor cells and tissue-resident stem cells
Anti-fibrotic — Reduces scar tissue formation, promotes organized collagen deposition
Hair Follicle Stimulation — Promotes hair follicle stem cell migration and differentiation
Where people usually see it discussed
Wound Healing (Primary FDA Review Indication) +
- Chronic non-healing wounds
- Surgical wound healing
- Burn healing
- Diabetic ulcers
- Corneal wounds (RGN-259 clinical trials)
Cardiovascular +
- Post-myocardial infarction cardiac repair
- Cardioprotection
- Vascular healing
Musculoskeletal +
- Muscle tears and strains
- Tendon/ligament repair
- Joint inflammation
- Bone fracture healing
Dermatological +
- Hair regrowth (follicle stem cell activation)
- Scar reduction
- Skin aging
Neurological +
- Traumatic brain injury (preclinical)
- Multiple sclerosis (remyelination)
- Peripheral nerve repair
Formal evidence and study snapshots
Deep Dive: Clinical Trials +
RGN-259 (NCT01451346)
Phase IIRegeneRx
Dry eye / corneal wound
RGN-259 (NCT02016131)
Phase IIIRegeneRx
Neurotrophic keratopathy
RGN-352 (NCT01311518)
Phase IRegeneRx
Acute MI (cardiac)
RGN-137 (topical)
Phase IIRegeneRx
Epidermolysis bullosa
Multiple veterinary
N/AVarious
Equine tendon healing
What the current safety discussion looks like
- ✓Endogenous protein — Tβ4 is naturally present in all human cells at high concentrations
- ✓Phase I cardiac trial — No serious adverse events at any dose tested
- ✓Ophthalmic trials — Well-tolerated, no significant ocular adverse events
- ✓Theoretical cancer concern — Some in vitro studies show Tβ4 may promote tumor cell migration (contested; epidemiological data does not support increased cancer risk)
- ✓WADA banned substance — Listed since 2012 for performance-enhancing potential
- ✓No hepatotoxicity, nephrotoxicity, or cardiotoxicity reported in clinical trials
- ✓Injection site reactions — Mild, transient (preclinical and clinical)
How the status timeline currently reads
Pre-2023
Category 1 — eligible for 503A compounding
September 2023
Moved to Category 2
April 2026
FDA announces PCAC review
July 23-24, 2026
Advisory committee review for wound healing indication
How dosing is usually described
Subcutaneous Injection
Loading phase: 2-2.5 mg twice weekly for 4-6 weeks Maintenance: 2 mg once weekly or every 2 weeks Injury-specific: Can be injected near injury site
Reconstitution
Typically supplied as lyophilized powder (2mg or 5mg vials) Reconstituted with bacteriostatic water
Duration
Loading: 4-6 weeks Maintenance: 4-8 additional weeks Often cycled with BPC-157 for synergistic healing
Research protocols only. Not medical advice.
The citations behind the page
Deep Dive: Key Research Papers +
- 1
Bock-Marquette I, et al.*. "Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair." Nature 2004.
- 2
Sosne G, et al.*. "Thymosin beta 4 promotes corneal wound healing and decreases inflammation." Experimental Eye Research 2002.
- 3
Goldstein AL, et al.*. "Thymosin β4: a multi-functional regenerative peptide." Expert Opinion on Biological Therapy 2012.
- 4
Malinda KM, et al.*. "Thymosin β4 accelerates wound healing." Journal of Investigative Dermatology 1999.
- 5
Philp D, et al.*. "Thymosin beta 4 increases hair growth by activation of hair follicle stem cells." FASEB Journal 2004.
- 6
Smart N, et al.*. "Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization." Nature 2007.
- 7
Hinkel R, et al.*. "Thymosin β4 is an essential paracrine factor of embryonic endothelial progenitor cell-mediated cardioprotection." Circulation 2008.
- 8
Crockford D.*. "Development of thymosin beta4 for treatment of patients with ischemic heart disease." Annals of the New York Academy of Sciences 2007.
Common questions about TB-500
What is TB-500? +
TB-500 is Thymosin Beta-4 Fragment, one of the peptides currently under review in connection with wound healing.
What is TB-500 being reviewed for? +
The current advisory review focuses on wound healing, with a listed review date of July 23-24, 2026.
Which category does TB-500 belong to? +
TB-500 is grouped in this library under Healing and Recovery.
How many amino acids are in TB-500? +
TB-500 is presented here as a 17-amino-acid peptide or peptide analog based on the source research and naming conventions.
What is the sequence or structure note for TB-500? +
Linear peptide fragment.
What research applications are most associated with TB-500? +
Chronic non-healing wounds, Surgical wound healing, Burn healing, and Diabetic ulcers
How is TB-500 described as working in the current research? +
Binds G-actin monomers, regulating cytoskeletal dynamics for cell migration. Helps promote migration of endothelial cells, keratinocytes, and stem cells to injury sites.
How is TB-500 usually discussed in protocols or treatment plans? +
TB-500 is most often described with under-the-skin injection and reconstitution protocols in the source material.
What does the safety discussion say about TB-500? +
Endogenous protein — Tβ4 is naturally present in all human cells at high concentrations Phase I cardiac trial — No serious adverse events at any dose tested
Continue the comparison
BPC-157
BPC-157 is a peptide people usually talk about for Ulcerative colitis and Inflammatory bowel disease. It is still in the FDA review process, so people are watching both the research and the access question closely.
PEG-MGF
PEG-MGF is a peptide people usually talk about for Muscle Wasting and Sarcopenia: Potential to counteract age-related muscle loss and wasting diseases by replenishing the satellite cell pool. and Injury Repair: Accelerating recovery from severe muscle, tendon, and ligament injuries.. It is still in the FDA review process, so people are watching both the research and the access question closely.
GHK-Cu
GHK-Cu is a peptide people usually talk about for Skin Rejuvenation: Improves skin elasticity, firmness, and thickness while reducing wrinkles, hyperpigmentation, and photodamage. and Wound Healing: Accelerates the healing of chronic wounds, surgical incisions, and burns by promoting tissue remodeling and angiogenesis.. It is still in the FDA review process, so people are watching both the research and the access question closely.
Get notified when TB-500 becomes available
Join the waitlist for peptide-specific updates, regulatory milestones, and access news connected to the GobyMeds care pathway.