Tissue repair, wound healing, musculoskeletal recovery
Not FDA-approved
Prohibited (S0)
SC, IM (parenteral)
Overview
TB-500 is a synthetic peptide sold in gray-market research channels that has been analytically identified (in at least some products) as Ac-LKKTETQ (N-acetyl-LKKTETQ), a short fragment corresponding to the actin-binding region of thymosin β4 [1]. This identification was first reported in an anti-doping and analytical chemistry context in 2012.
The LKKTET motif is part of thymosin β4's actin-binding domain, mapped in structure–function work from the 1990s [2]. The parent molecule, thymosin β4, a 43-amino-acid peptide, was originally isolated and characterized from thymus tissue in the early 1980s [3].
Research Areas and Claims
Common marketed claims are largely borrowed from the broader thymosin β4 literature. No claims below have been validated in large-scale human trials specifically for TB-500 or Ac-LKKTETQ.
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Tissue Repair: Marketed as supporting soft tissue recovery, including tendons, ligaments, and muscle [6][4].
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Wound Healing: Vendor claims reference angiogenesis support and accelerated wound closure, derived from thymosin β4 preclinical data [7].
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Inflammation Reduction: Anti-inflammatory effects are commonly cited in marketing materials, again extrapolated from the parent compound [6].
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Musculoskeletal Recovery: Often marketed for athletic recovery contexts; no clinical proof exists for TB-500 specifically in this application [4][6].
Mechanism of Action
Note: The mechanistic rationale for TB-500 is borrowed from thymosin β4 biology. No independent mechanism has been validated specifically for Ac-LKKTETQ in human subjects.
- G-Actin Binding & Cytoskeletal Dynamics: Thymosin β4 sequesters G-actin monomers, modulating cytoskeletal remodeling. The LKKTET motif, corresponding to the TB-500 fragment, is the key actin-binding region responsible for this activity [2].
- Cell Migration: By influencing actin dynamics, thymosin β4 promotes the migration of endothelial cells, keratinocytes, and other repair-relevant cell types, contributing to wound closure and tissue regeneration [7].
- Angiogenic Signaling: Preclinical evidence associates thymosin β4 with promotion of new blood vessel formation, supporting tissue repair after injury [7].
Clinical Trials
Key distinction: No high-quality interventional human trial program specifically for TB-500 or Ac-LKKTETQ has been identified [1]. The trials below are for full-length thymosin β4 (timbetasin / RGN-259), the parent compound that vendors often cite to imply support for TB-500. These are not evidence for injectable TB-500.
| Study & Year | Design & Indication | Route | Outcome / Status | Ref |
|---|---|---|---|---|
| NCT00832091 (2006) | Phase II, Venous stasis ulcers | Topical gel | Results posted 2010; safety/tolerability evaluated | [9] |
| NCT00382174 | Pressure ulcers | Topical | Wound-healing evaluation | [10] |
| ARISE-2 (2016) | Phase III, Dry eye disease (RGN-259) | Ophthalmic drops | Primary endpoints not met | [11] |
| ARISE-3 (2019) | Phase III, Dry eye disease (RGN-259) | Ophthalmic drops | Mixed; secondary symptom signals in some analyses | [13] |
| NCT03578029 (2018) | Epidermolysis bullosa wounds (RGN-137) | Topical gel | Terminated; last posted 2022 | [15] |
Administration Methods in Clinical Trials
Important Safety & Regulatory Information
- FDA Status: Not FDA-Approved. TB-500 is sold as a research peptide and is not approved for human use. Risks include unknown purity, contamination, and undefined long-term safety profiles.
- Sports Compliance: Prohibited. TB-500 is prohibited by the World Anti-Doping Agency (WADA) under the S0 (Non-approved substances) category [1].
- Product Inconsistency: The composition of products sold as "TB-500" varies across vendors. Some contain Ac-LKKTETQ (a fragment); others may contain full-length thymosin β4. Researchers should verify exact composition via independent analytical testing [4][6].
- Dosing: No evidence-based dosing schedule has been established in humans for TB-500 / Ac-LKKTETQ. Any schedule encountered in vendor or clinic materials represents community protocol, not validated medical dosing.
Market Overview
Please note: The following data is based on February–March 2026 pricing. All products are strictly sold as research chemicals. Prices fluctuate based on volume, batch, purity, and presentation.
Injectable
SC / IMLyophilized powder reconstituted for subcutaneous or intramuscular research use.
- Retail Price Range: $4.90 – $17.00 per mg
- B2B Reference: ~$1.20/mg (Chinese supplier)
- Typical Sizes: 5mg, 10mg, 20mg, 50mg, 100mg
- Vendors with pricing: 15
Nasal Spray
IntranasalPre-mixed intranasal spray. Bioavailability via this route is not established in clinical literature.
- Price: $20.06 per mg
- Typical Sizes: 10mg per bottle
- Vendors with pricing: 1
Oral Sublingual
SublingualSublingual tablet format. Bioavailability via this route is not established in clinical literature.
- Price Range: $21.02 – $23.24 per mg
- Typical Sizes: 7.5mg, 15mg per bottle
- Vendors with pricing: 1
Vendor Directory
Data collected February–March 2026. Tables are split by route of administration; vendors without public pricing are listed separately below.
Injectable: Lyophilized Powder (SC / IM)
| Vendor | Sizes (mg) | Price Range ($/mg) | Website |
|---|---|---|---|
| Peptide Partners | 20 / 50 / 100 | $4.90 – $6.50 | peptide.partners |
| Planet Peptide | 10 | $5.50 ★ | planetpeptide.com |
| Simple Peptide | 10 | $5.85 – $6.50 | simplepeptide.com |
| Alpha Omega Peptide | 10 | $6.50 | alphaomegapeptide.com |
| PurePEPS | 5 / 10 | $6.50 – $6.80 | purepeps.com |
| Peptidology | 10 | $7.00 | peptidology.co |
| Nova Peptide Supply | 5 / 10 | $7.00 – $7.50 | novapeptidesupply.com |
| NuScience Peptides | 5 / 10 | $7.50 – $8.00 | nusciencepeptides.com |
| Amino Asylum | 5 | $8.00 | amino-asylum.net |
| Uther | 10 | $8.00 | utherpeptide.com |
| BioLongevity Labs | 10 | $11.55 † | biolongevitylabs.com |
| Biotech Peptides | 10 | $12.40 | biotechpeptides.com |
| Core Peptides | 5 / 10 | $14.00 – $15.60 | corepeptides.com |
| Peptide Sciences | 5 / 10 | $16.50 – $17.00 | peptidesciences.com |
| Reta-Peptide | 100 (10×10mg) | $1.20 ‡ | reta-peptide.com |
Nasal Spray (Intranasal)
| Vendor | Format | Size (mg) | Price ($/mg) | Website |
|---|---|---|---|---|
| Pure Rawz | Nasal spray | 10 | $20.06 | purerawz.co |
Oral: Sublingual Tablets
| Vendor | Format | Size (mg) | Price ($/mg) | Website |
|---|---|---|---|---|
| Pure Rawz | Sublingual tablets | 7.5 / 15 | $21.02 – $23.24 | purerawz.co |
* Data Notes: Data collected February–March 2026. Sale prices used where publicly displayed. ★ Planet Peptide price reflects a sale (regular $8.00/mg); buyer-tiered pricing applies. † BioLongevity Labs price reflects a 30% sitewide sale (regular $16.50/mg). ‡ Reta-Peptide is a Chinese manufacturer; $1.20/mg is a B2B bulk reference price, not a retail listing. Prices subject to change. All products sold strictly for in-vitro research purposes only.
No Public Pricing / B2B / Wholesale / Inactive
These vendors carry or have carried TB-500 but do not list public retail prices, have no standalone product, or could not be confirmed. Contact them directly for availability and quotes.
| Vendor | Status | Website |
|---|---|---|
| Verified Peptides | Product page 404 (Mar 2026) | verifiedpeptides.com |
| Paramount Peptides | No standalone TB-500 (combo products only) | paramountpeptides.com |
| Swiss Chems | No standalone TB-500 (BPC-157/TB-500 blend only) | swisschems.is |
| Atomik Labz | Availability unconfirmed (requires login) | atomiklabz.com |
| LiliPeptide | B2B / wholesale only | lilipeptide.com |
| SRY Labs | B2B / wholesale only | srylab.bio |
| Qing Li Peptide | B2B / wholesale only | qinglishangmao.com |
| ZLZ Peptide | B2B / wholesale only | zlzpeptide.com |
| Wuhan Wansheng Biotechnology | B2B / wholesale only | wuhanwansheng.net |
| Shanghai Sigma Audley (SSA) | Website down (Feb 2026) | sigmaaudley.net |
References
- Esposito S, Deventer K, Van Eenoo P. "Qualitative detection of thymosin β4 and its metabolites in urine by LC–MS/MS." Journal of Mass Spectrometry (2012).
- Van Troys M, Vandekerckhove J, Ampe C. Actin-binding site mapping / LKKTET motif work on β-thymosins (1990s).
- Low TLK, Goldstein AL. Early isolation and characterization of thymosin β4 from thymus extracts (early 1980s).
- Core Peptides. TB-500 product page. corepeptides.com
- Biotech Peptides. TB-500 product page. biotechpeptides.com
- Survival Supplements. TB-500 product page. survival-supplements.com
- Kleinman HK, Sosne G. "Thymosin β4 Promotes Dermal Healing." Advances in Wound Care (2016). [PMID: 27450738]
- Sosne G, et al. "0.1% RGN-259 Ophthalmic Solution…" (2022). [PMID: 36613994]
- NCT00832091 — Thymosin Beta 4 in Venous Stasis Ulcers. Start 2006-07; Results posted 2010-03-24. clinicaltrials.gov
- NCT00382174 — Thymosin Beta 4 in Pressure Ulcers. clinicaltrials.gov
- NCT02974907 (ARISE-2). Start Nov 30, 2016; Completion Sept 30, 2017. Primary endpoints not met. trialstracker.net
- ARISE-2 Protocol. Protocol PDF
- NCT03937882 (ARISE-3). Mixed endpoint performance; secondary symptom signals in some analyses. clinicaltrials.gov
- ReGenTree ARISE-3 press release (May 14, 2021). prnewswire.com
- NCT03578029 — RGN-137 topical gel for Epidermolysis Bullosa. First posted 2018-07-05; Terminated; last posted 2022-08-22. clinicaltrials.gov
- Peptide Sciences. TB-500 product page. peptidesciences.com
- Gentleman Peptides. TB500 5mg. gentlemanpeptides.com