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.
-
Tissue Repair: Marketed as supporting soft tissue recovery, including tendons, ligaments, and muscle [6][4].
-
Wound Healing: Vendor claims reference angiogenesis support and accelerated wound closure, derived from thymosin β4 preclinical data [7].
-
Inflammation Reduction: Anti-inflammatory effects are commonly cited in marketing materials, again extrapolated from the parent compound [6].
-
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.
NCT00832091 (2006)
NCT00382174
ARISE-2 (2016)
ARISE-3 (2019)
NCT03578029 (2018)
| Study & Year | Design | Route | Duration | Key Finding | 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 – $23.24 per mg
- Typical Sizes: 7.5mg, 15mg per bottle
- Vendors with pricing: 1
Vendor Directory
Data collected February–March 2026. Tables are split by route of administration; vendors without public pricing are listed separately below.
Injectable: Lyophilized Powder (SC / IM)
Peptide Partners
Planet Peptide
Simple Peptide
Alpha Omega Peptide
PurePEPS
Peptidology
Nova Peptide Supply
NuScience Peptides
Amino Asylum
Uther
BioLongevity Labs
Biotech Peptides
Core Peptides
Peptide Sciences
Reta-Peptide
| Vendor | Sizes (mg) | Price Range ($/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) | $1.20 ‡ | reta-peptide.com |
Nasal Spray (Intranasal)
Pure Rawz
| Vendor | Format | Size (mg) | Price ($/mg) | Website |
|---|---|---|---|---|
| Pure Rawz | Nasal spray | 10 | $20.06 | purerawz.co |
Oral: Sublingual Tablets
Pure Rawz
| Vendor | Format | Size (mg) | Price ($/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.
Verified Peptides
Paramount Peptides
Swiss Chems
Atomik Labz
LiliPeptide
SRY Labs
Qing Li Peptide
ZLZ Peptide
Wuhan Wansheng Biotechnology
Shanghai Sigma Audley (SSA)
| 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