Ask sales for the lot-numbered COA matched to the offered or supplied batch; it records the tests actually completed, their specifications, and the reported results.

Matching batch COA available.

PCAC will review 7 peptides for the 503A bulks list, BPC-157, KPV, TB-500, MOTS-c, Emideltide, Semax, Epitalon. Read our briefing →

FDA PCAC reviews 7 peptides in July. Read →

TB-500

Name: TB-500
Brand: PeptideXpo
SKU: tb-500

Thymosin β4 fragment

≥ 99.0%CAS 77591-33-4Repair Peptides

PeptideXpo buyer fit

TB-500 for distributor assortment and OEM sourcing comparison

This PeptideXpo page is intentionally positioned for distributors, OEM buyers, and procurement teams comparing TB-500 inside a wider peptide catalog. It is not trying to be the deepest single-molecule monograph; the differentiated intent is assortment planning, export-ready documentation, fill-size comparison, and whether this SKU belongs in a broader buyer program.

Use this page when the buyer is comparing multiple SKUs, fill ladders, repeat-order economics, or distributor/OEM sourcing routes.
For regulated compounding-pharmacy qualification, a dedicated regulated-pharmacy channel should own the pharmacy-specific head keyword.
For research-lab method development, copper-chemistry, or cosmetic-formulation depth, the matching specialist channel (research standards, copper peptides, or cosmetic actives) should own the narrower specialist intent.

Overview

TB-500 is a 43-amino-acid synthetic peptide derived from Thymosin β4 (the actin-sequestering protein expressed natively in nearly every mammalian cell type). The molecule's biological activity centers on actin-binding via its central LKKTETQ motif and downstream effects on cellular migration, angiogenesis, and tissue regeneration, the mechanistic basis for the broad TB-500 research literature on wound healing, cardiac remodeling, and tendon-ligament repair models. TB-500's longer sequence relative to BPC-157 makes it serum-stable but not orally bioavailable, so research workflows are exclusively injectable-route. TB-500 is on the July 2026 FDA PCAC agenda for 503A bulks-list consideration with the proposed indication of wound healing. PeptideXpo supplies TB-500 acetate as a lyophilized powder at ≥99.0% HPLC purity. The 43-residue sequence is at the upper-middle range for routine SPPS, synthesis is reliable but purification cycles are more demanding than for shorter peptides like BPC-157, and the analytical packet emphasizes peak-integration HPLC plus mass spec to clear deletion sequences that elute close to the target peak. Sequence verification by LC-MS/MS is available on request and is the recommended qualification test for any TB-500 supplier, for a 43-mer, mass alone leaves more identity ambiguity than for a 15-mer like BPC-157. TB-500 is most commonly ordered as the standalone vial or as the Wolverine Blend with BPC-157 (5+5 mg per 10 mg vial standard, custom ratios via OEM). For the full BPC-157 vs TB-500 mechanism and analytical comparison, see our [side-by-side article](/insights/bpc-157-vs-tb-500-side-by-side); for the 503A regulatory context, see our [503A vs 503B compounding guide](/insights/503a-vs-503b-compounding-pharmacy-peptides).

Who buys this, and why

Repair peptides, BPC-157, TB-500, and related sequences, typically ship to research labs studying tissue-repair, gastrointestinal, or tendon-ligament models. Ask sales for the COA matched to the offered or supplied lot. If the buyer's written qualification procedure requires tandem-MS sequence evidence, include it in the agreed scope before quotation rather than treating it as an automatic first-batch retest.

Primary buyer fit: 503A / 503B compounding pharmacies and academic and contract research laboratories.

Specifications

CAS: 77591-33-4
Sequence: SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES
Appearance: White to off-white lyophilized powder
Purity (HPLC): ≥ 99.0%
Strength: 2 mg – 10 mg
Packaging: 10 vials/box · base pack (multiples of 10)
Half-life: ≈ 1.5-3 hours
MOQ: On request
Lead time: 7–14 days
Storage: 2–8°C, protect from light

Documentation available on request

Certificate of Analysis (COA)
HPLC Chromatogram
Mass-spec identity (ESI-MS)
Sequence verification (LC-MS/MS)
Water content (Karl Fischer)
Counter-ion analysis
SDS / MSDS
Stability data on request

Regulatory note

Currently under FDA PCAC review (July 2026) for inclusion on the 503A bulks list, with the proposed indication of wound healing.

Selected literature

Esposito S, Deventer K, Goeman J, Van der Eycken J, Van Eenoo P. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal. 2012;4(9):733-738.
Philp D, Huff T, Gho YS, Hannappel E, Kleinman HK. The actin binding site on thymosin beta4 promotes angiogenesis. FASEB J. 2003;17(14):2103-2105.
Bock-Marquette I, Saxena A, White MD, DiMaio JM, Srivastava D. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472.
Xing Y, Ye Y, Zuo H, Li Y. Progress on the function and application of thymosin β4. Front Endocrinol (Lausanne). 2021;12:767785.
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. 0.1% RGN-259 (Thymosin β4) ophthalmic solution promotes healing and improves comfort in neurotrophic keratopathy patients in a randomized, placebo-controlled, double-masked phase III clinical trial. Int J Mol Sci. 2022;24(1):554.
Wei C, Kumar S, Kim IK, Gupta S. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes. PLoS One. 2012;7(8):e42586.

Frequently asked questions

What is TB-500 and how does it differ from native Thymosin β4?▾

TB-500 is a 43-amino-acid synthetic peptide derived from a defined region of native Thymosin β4 (which is a 44-residue protein in mammals). The synthetic TB-500 sequence includes the LKKTETQ actin-binding motif that drives the molecule's biological activity. Compared with native Thymosin β4 produced recombinantly, the synthetic TB-500 is more economically accessible at research and commercial scale and avoids the variability that comes with cell-line-expressed material. The biological activity per mass is functionally equivalent for the actin-binding and tissue-regeneration readouts that dominate the TB-500 research literature.

Why is sequence verification more important for TB-500 than for shorter repair peptides?▾

TB-500 is 43 amino acids, which is at the upper-middle end of routine SPPS. Longer peptides accumulate more single-residue deletion sequences during synthesis, and those deletion products elute close to the target peak on RP-HPLC, they pass the standard HPLC purity gate but are not the molecule the buyer ordered. Mass spec alone catches identity to within 0.5 Da but cannot distinguish between, say, a [Lys-deletion at position 12] and a [Lys-deletion at position 30] of equal residue mass. LC-MS/MS sequence verification with full b- and y-ion ladder coverage is the only test that directly demonstrates the synthesized sequence matches the labelled sequence, available when required by a written analytical scope for any 40+ residue peptide.

What's the practical difference between using TB-500 alone vs. the Wolverine Blend with BPC-157?▾

TB-500 and BPC-157 act through different molecular mechanisms, TB-500 is an actin-binding peptide affecting cellular migration and tissue remodeling, while BPC-157 acts through nitric-oxide-pathway modulation and growth-factor-receptor cross-talk. The two are commonly combined in research and compounding contexts because the mechanisms are complementary rather than redundant. The Wolverine Blend SKU bundles both peptides into a single co-lyophilized vial at a standard 5+5 mg ratio (custom ratios available); the combined vial simplifies handling and the analytical packet certifies both components in a single document.

Related peptides

Buyers who view TB-500 also ask about:

15-mer

BPC-157

≥99.0%

Body Protection Compound 15-mer

CAS: 137525-51-0
Vial: 2 mg–20 mg

MOQ on requestGet quote →

Wolverine Blend

≥99.0%

BPC-157 + TB-500 repair-stack blend

CAS: —
Vial: 20 mg

MOQ on requestGet quote →

See full catalog

TB-500

Thymosin β4 fragment

≥ 99.0%CAS 77591-33-4Repair Peptides

PeptideXpo buyer fit

TB-500 for distributor assortment and OEM sourcing comparison

Use this page when the buyer is comparing multiple SKUs, fill ladders, repeat-order economics, or distributor/OEM sourcing routes.
For regulated compounding-pharmacy qualification, a dedicated regulated-pharmacy channel should own the pharmacy-specific head keyword.
For research-lab method development, copper-chemistry, or cosmetic-formulation depth, the matching specialist channel (research standards, copper peptides, or cosmetic actives) should own the narrower specialist intent.

Overview

Who buys this, and why

Primary buyer fit: 503A / 503B compounding pharmacies and academic and contract research laboratories.

Specifications

CAS: 77591-33-4
Sequence: SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES
Appearance: White to off-white lyophilized powder
Purity (HPLC): ≥ 99.0%
Strength: 2 mg – 10 mg
Packaging: 10 vials/box · base pack (multiples of 10)
Half-life: ≈ 1.5-3 hours
MOQ: On request
Lead time: 7–14 days
Storage: 2–8°C, protect from light

Documentation available on request

Certificate of Analysis (COA)
HPLC Chromatogram
Mass-spec identity (ESI-MS)
Sequence verification (LC-MS/MS)
Water content (Karl Fischer)
Counter-ion analysis
SDS / MSDS
Stability data on request

Regulatory note

Currently under FDA PCAC review (July 2026) for inclusion on the 503A bulks list, with the proposed indication of wound healing.

Selected literature

Esposito S, Deventer K, Goeman J, Van der Eycken J, Van Eenoo P. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal. 2012;4(9):733-738.
Philp D, Huff T, Gho YS, Hannappel E, Kleinman HK. The actin binding site on thymosin beta4 promotes angiogenesis. FASEB J. 2003;17(14):2103-2105.
Bock-Marquette I, Saxena A, White MD, DiMaio JM, Srivastava D. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472.
Xing Y, Ye Y, Zuo H, Li Y. Progress on the function and application of thymosin β4. Front Endocrinol (Lausanne). 2021;12:767785.
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. 0.1% RGN-259 (Thymosin β4) ophthalmic solution promotes healing and improves comfort in neurotrophic keratopathy patients in a randomized, placebo-controlled, double-masked phase III clinical trial. Int J Mol Sci. 2022;24(1):554.
Wei C, Kumar S, Kim IK, Gupta S. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes. PLoS One. 2012;7(8):e42586.

Frequently asked questions

What is TB-500 and how does it differ from native Thymosin β4?▾

Why is sequence verification more important for TB-500 than for shorter repair peptides?▾

What's the practical difference between using TB-500 alone vs. the Wolverine Blend with BPC-157?▾

Related peptides

Buyers who view TB-500 also ask about:

15-mer

BPC-157

≥99.0%

Body Protection Compound 15-mer

CAS: 137525-51-0
Vial: 2 mg–20 mg

MOQ on requestGet quote →

Wolverine Blend

≥99.0%

BPC-157 + TB-500 repair-stack blend

CAS: —
Vial: 20 mg

MOQ on requestGet quote →

See full catalog