If a supplied lot fails agreed specifications, we’ll replace it at no cost or refund its purchase price in full.
Quality test failed? Free replacement or full refund.
Off-spec? Free replacement or full refund.
PCAC will review 7 peptides for the 503A bulks list, BPC-157, KPV, TB-500, MOTS-c, Emideltide, Semax, Epithalon. Read our briefing →
PCAC will review 7 peptides for the 503A bulks list. Read →
FDA PCAC reviews 7 peptides in July. Read →
Also known as TB-500 · Thymosin beta-4 (full-length) · Thymosin Beta-4 · Thymosin β4 · Tβ4 · TB4 · TB-4 · TB500 · Timbetasin
Full-length Thymosin β4 (43 residues)
Supply and ordering
Ask sales about TB-500 (Thymosin Beta-4, full-length) availability, order quantities, packaging, and batch documentation. Include other catalog items in the same inquiry if you are planning a combined or recurring order.
Overview
TB-500 here is synthetic full-length Thymosin β4: the 43-amino-acid, N-terminally acetylated actin-sequestering peptide expressed natively in nearly every mammalian cell type. It is not the seven-residue Ac-LKKTETQ fragment (residues 17–23), which is listed separately as TB-500 (fragment 17-23). 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 to a ≥99.0% HPLC purity specification. 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; for the 503A regulatory context, see our 503A vs 503B compounding guide.
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
Also available as a nasal spray (US stock)
Besides lyophilized vials, TB-500 (Thymosin Beta-4, full-length) is stocked in the US as a ready-to-use nasal spray.
Documentation available on request
Each picture is a low-resolution preview of a report's first page, with batch and report numbers covered. For the full, clear report, ask our sales team, naming the product and strength.
Batch COATB-500 (Thymosin Beta-4, full-length) 2 mg
HPLC purity · MS identity
Batch COA
Full, clear copy from sales
Batch COATB-500 (Thymosin Beta-4, full-length) 5 mg
HPLC purity · MS identity
Batch COA
Full, clear copy from sales
Batch COATB-500 (Thymosin Beta-4, full-length) 10 mg
HPLC purity · MS identity
Batch COA
Full, clear copy from sales
Third-party reportTB-500 / Thymosin beta-4 10 mg
HPLC purity · MS identity
Third-party laboratory, Tianjin, China
Full, clear copy from sales
Independent test fails? Full refund. How it works
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
Frequently asked questions
TB-500 as supplied here is the complete 43-residue sequence of mature, N-terminally acetylated Thymosin β4 (the 44-residue figure sometimes quoted refers to the precursor including the initiator methionine). The sequence includes the LKKTETQ actin-binding motif (residues 17–23) that drives the molecule's biological activity; the isolated seven-residue Ac-LKKTETQ fragment is a different, much smaller molecule and is listed separately. Compared with native Thymosin β4 produced recombinantly, the synthetic peptide 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.
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.
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 one batch COA reports HPLC purity and MS identity for both components.
Yes. TB-500 (Thymosin Beta-4, full-length) is also stocked as a ready-to-use nasal spray (2 mg, 5 mg, 10 mg) in 10 mL or 20 mL bottles, from 10 bottles of each. These orders ship from our US stock; ask our sales team for details and a quote.
Send any vial from your order to an independent laboratory of your choice. If the report shows the product does not meet the specification on its COA — purity below the stated minimum, or an identity that does not match — share the report with our sales team and we refund that product in full.
Related peptides
15-mer
Body Protection Compound 15-mer
Nasal spray availableCapsules available
BPC-157 + TB-500 repair-stack blend
Thymosin β4 active-fragment preparation
