TB-500 2mg
Certificate of Analysis available
TB-500
CAS # 77591-33-4
Mol. weight 4963.44 g/mol
Formula C212H350N56O78S
Identity
Manufacturer Generic Peptides
Active substance Thymosin Beta-4 (Tβ4) — 43-amino-acid peptide
Synonyms Thymosin β4; Tβ4; TB4; Timbetasin
Composition
Form Lyophilized powder
Purity ≥ 99% HPLC
Sequence Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser (43 aa)
Product usage — Research only
- For in vitro testing and laboratory research only.
- Not for human or animal consumption.
- Not intended for administration to humans or animals.
- Handle according to applicable laboratory safety procedures.
- Not an FDA-approved drug, food, or cosmetic.
- Educational and experimental laboratory research only.
TB-500 is a commercial name used for several thymosin beta-4-related research materials. The product specifications on this page identify the offered material as full-length, N-terminally acetylated thymosin beta-4 (Tβ4): a 43-amino-acid peptide studied in actin regulation, cellular migration, angiogenesis, and tissue-repair models.
Identity at a glance: This product is full-length Tβ4 (43 amino acids). It is not the seven-amino-acid Ac-LKKTETQ substance evaluated by FDA as TB-500 in 2026.
What Is TB-500?
The name "TB-500" does not identify one universal molecule. Researchers may encounter three related but non-interchangeable materials:
- Full-length Tβ4: the N-terminally acetylated 43-amino-acid peptide. The sequence, molecular weight, CAS number, and formula shown in this listing correspond to this material.
- LKKTETQ (Fequesetide): the unacetylated seven-amino-acid sequence corresponding to residues 17–23 of Tβ4.
- Ac-LKKTETQ: the N-terminally acetylated version of the seven-amino-acid sequence. FDA evaluated its free-base and acetate-salt forms as TB-500 in 2026.
These materials differ in sequence, molecular weight, and supporting evidence. A commercial name alone cannot establish identity; researchers should match the stated sequence and analytical documentation to the material required by the study.
Why Researchers Study Full-Length Tβ4
Full-length Tβ4 binds monomeric G-actin and helps regulate its availability for polymerization into F-actin. This actin-sequestering function makes the peptide relevant to research on cytoskeletal organization, cell shape, and cell movement.
Published laboratory and animal studies have examined full-length Tβ4 or related sequences in:
- actin dynamics and cytoskeletal remodeling;
- keratinocyte and endothelial-cell migration;
- angiogenesis and progenitor-cell activity;
- cardiac-cell migration and tissue-repair models.
LKKTETQ is derived from a region associated with actin binding, but that relationship does not make the seven-amino-acid fragment equivalent to full-length Tβ4. Results obtained with one molecular form should not be attributed to another without direct supporting evidence.
Product Identity and Documentation
This listing identifies the product as full-length Tβ4 with a 43-amino-acid sequence and ≥99% HPLC purity. Before beginning a study, confirm the selected strength and compare the sequence, molecular weight, CAS number, stated purity method, and batch-specific analytical report.
Certificates are displayed in the COA tab for the available 2 mg, 5 mg, and 10 mg strengths. The batch documentation—not the TB-500 name by itself—should be used to verify that the supplied material matches the experimental design.
Regulatory Status
TB-500 is not an FDA-approved drug. During its July 23–24, 2026 meeting, the Pharmacy Compounding Advisory Committee voted 8–6, with one abstention, to recommend including TB-500 free base and TB-500 acetate on the Section 503A Bulks List. FDA's review concerned the N-terminally acetylated heptapeptide Ac-LKKTETQ, not the full-length 43-amino-acid Tβ4 offered on this page. The committee's recommendation is advisory and does not constitute FDA approval or final inclusion on the Bulks List.
For the complete regulatory record, read our TB-500 FDA review update and the official FDA meeting materials. WADA lists thymosin-β4 and its derivatives, including TB-500, on the Prohibited List for athletes subject to anti-doping rules.
Related Research Materials
TB-500 and BPC-157 are different experimental peptides with different sequences, mechanisms, and evidence bases. Researchers comparing the two should treat them as separate materials rather than assuming that frequent co-mention establishes a validated combination. See the BPC-157 product overview for product identity and batch documentation, and our BPC-157 FDA review update for regulatory context.
Ordering and Shipping
Review the available strength and corresponding COA before ordering. For current processing times, delivery estimates, tracking, and payment information, see Shipping & Payments.
For laboratory research only. Not for human or animal consumption.
Sources
Bock-Marquette I et al. — "Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair." Nature, 2004. PubMed record
Smart N et al. — "Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization." Nature, 2007. PubMed record
Philp D, Badamchian M, Scheremeta B et al. — "Thymosin beta 4 and a synthetic peptide containing its actin-binding domain promote dermal wound repair in db/db diabetic mice and in aged mice." Wound Repair and Regeneration, 2003. PubMed record
Goldstein AL, Hannappel E, Kleinman HK — "Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues." Trends in Molecular Medicine, 2005. PubMed record
PubChem — Fequesetide compound record.
FDA — TB-500 briefing document and July 23–24, 2026 PCAC meeting materials.
World Anti-Doping Agency — The Prohibited List.
TB-500 Storage and Handling
Recommended storage: Keep the unopened lyophilized vial at −20°C (−4°F), tightly sealed, dry, and protected from light. For extended storage up to 24 months, use −80°C (−112°F).
Storage Instructions
| Situation | What to Do | FDA Reference Period |
|---|---|---|
| Standard freezer storage | Store the unopened vial at −20°C (−4°F), in its original packaging, protected from light and moisture. | Up to 12 months for TB-500 free-base powder stored sealed under nitrogen. |
| Extended storage | Store the unopened vial at −80°C (−112°F). Keep the original seal intact. | Up to 24 months for TB-500 free-base powder stored sealed under nitrogen. |
| After delivery | Place the vial in freezer storage promptly. Keep it inside the original box or another light-protective secondary container. | Do not use room temperature as the planned storage condition. |
| Before opening | Remove the vial from the freezer and allow it to reach room temperature while it is still sealed. Open only after the vial has warmed. | This reduces condensation on the lyophilized material. |
| Repeated access | Avoid repeatedly moving the same vial between freezer and room temperature. Plan the laboratory workflow before opening it. | Repeated temperature cycling increases the opportunity for moisture exposure. |
Protect the Vial From
- direct sunlight and UV exposure;
- humidity, condensation, and contact with liquid;
- a loose stopper, damaged crimp seal, or cracked vial;
- repeated warming and cooling;
- long-term storage at room temperature.
What the Material Should Look Like
The lyophilized material should remain dry and white to off-white. A compact cake or plug can be normal for a freeze-dried peptide and is not, by itself, evidence of degradation. Do not use a vial with visible liquid, a damaged seal, marked discoloration, or a sticky or wet appearance.
Scope of the FDA data: FDA’s 2026 briefing document reports the 12- and 24-month periods for seven-amino-acid Ac-LKKTETQ free-base powder stored in a sealed container, under nitrogen, away from moisture and light. For TB-500 acetate, FDA cites refrigerated or frozen storage in a sealed container and separately reports stability below −15°C when tightly closed and protected from light. The product on this page is identified as full-length 43-amino-acid thymosin beta-4, so these values provide a conservative freezer-storage framework rather than a stability study of this exact full-length product.
Source: FDA, Evaluation of TB-500-Related Bulk Drug Substances, pp. 11, 15–16 and 19. For the regulatory outcome and molecular-identity distinction, see our TB-500 FDA review update.
Shipping & Product Authenticity
Orders are processed after payment confirmation and shipped with tracking. Delivery estimates begin when the parcel is dispatched, not when the order is placed.
Shipping Times
| Stage or Destination | Estimated Time | What to Expect |
|---|---|---|
| Order processing | 24–48 business hours | Processing begins after payment confirmation. |
| USA domestic | 2–5 business days after dispatch | Transit time depends on the destination and carrier network. |
| International | 10–15 business days after dispatch | Customs clearance and local-carrier handling can extend delivery. |
| Tracking | Sent after dispatch | Scan frequency may vary during export, customs clearance, and handoff to a local carrier. |
Secure and Discreet Delivery
TB-500 is packed in a sealed Generic Peptides vial and original product packaging. The shipping parcel is neutral and does not display the product name on the exterior. Orders are packed to protect the vial during transit and supplied with tracking after dispatch.
If an order is fulfilled from more than one warehouse, the products may arrive in separate tracked parcels.
How to Verify This TB-500 Product
This listing identifies the material as full-length, 43-amino-acid thymosin beta-4. Verify the selected strength against the vial label, product specifications, and corresponding third-party laboratory report before beginning a study.
| Verification Point | What to Check |
|---|---|
| Packaging | Generic Peptides label, intact vial, stopper, and aluminum crimp seal. |
| Product identity | Full-length Tβ4 sequence, CAS number, molecular weight, and formula shown in the product specifications. |
| Batch documentation | Third-party COA for the selected 2 mg, 5 mg, or 10 mg strength, including measured content, purity result, analysis date, and report identifier. |
| COA access | Open the COA tab and select the certificate that matches the ordered strength. |
For current delivery, payment, tracking, and reshipment terms, see Shipping & Payments. For questions about a specific order or batch, contact the Generic Peptides team.
Certificate of Analysis (COA)
Third-party laboratory reports are available for TB-500 2mg, 5mg, and 10mg batches. Each certificate provides batch-level verification details, including measured content, purity result, analysis date, and report documentation.
TB-500 5mg
Certificate of Analysis available
TB-500 10mg
Certificate of Analysis available
Select any certificate preview to open the full Certificate of Analysis.
Naomi Ross
- April 1, 2026
Actin-sequestering assays in endothelial cells. Behaved as the literature predicts.
R. Sanders
- March 20, 2026
Goldstein isolated this from calf thymus back in 1981 and it's been studied as a defined protein ever since — refreshing to work with something in this catalog that has a real, multi-group literature behind it rather than a single research program. Material gave clean results in our angiogenesis tube-formation assays.
Skylar Wood
- March 17, 2026
RegeneRx ran actual Phase 2 and Phase 3 trials on this — RGN-259 for ophthalmic, the cardiac and dermal programs. That's a genuine clinical evidence base, more than almost anything else in this space. We used it for corneal epithelial migration work and the material tracked with the published behavior.
P. Kelly
- March 12, 2026
Reorder for angiogenesis work. Full Tβ4, consistent.
Bennett
- March 4, 2026
We run Tβ4 against BPC-157 in parallel regenerative models — different mechanisms entirely, actin-sequestering versus whatever BPC does, but they're the two compounds everyone studies side by side in this area. Getting both from one source with matched documentation keeps the comparison honest. That's the value for this kind of work.
Ellie Ramirez
- February 22, 2026
Endothelial migration assays. No issues, three orders.
Nora W.
- February 17, 2026
Solid for our cardiac-repair preclinical models, where the angiogenic signaling is what we're after. The 43-mer is a moderately large peptide and I'd push the vendor to include mass-spec intactness verification as standard — longer sequences carry more truncation-product risk than the small peptides, and "purity by HPLC" alone doesn't fully reassure me at this length. Material checked out when I ran it myself.
Anthony Young
- January 30, 2026
The product page actually frames this as actin-cytoskeleton biology rather than a "recovery peptide," which is the correct scientific framing and almost nobody uses it. Tβ4's primary intracellular role is G-actin sequestering — the regenerative effects are downstream and extracellular. Nice to see a listing that leads with the real biology.
Barnes
- January 27, 2026
For corneal wound-healing research the RGN-259 development trajectory makes Tβ4 the obvious reference, and the material's been consistent enough to run a multi-timepoint migration study without re-validating between batches. The fact that there's a real ophthalmic clinical program behind it gives the in-vitro work a translational anchor.
Audrey
- January 21, 2026
Reliable in our scratch-wound migration assays. Reconstituted cleanly. The one ongoing friction is that Tβ4 aggregates somewhat in solution at higher concentrations, so we aliquot and keep working stocks dilute — not a vendor issue, just the peptide's behavior, but worth others knowing before they prepare concentrated stocks and watch them cloud.
TB-500 is a commercial name for thymosin beta-4-related research materials. Because it can describe different molecules, researchers should verify the sequence, molecular weight, CAS number, and batch documentation. This page supplies full-length, 43-amino-acid Tβ4.
This page supplies full-length, N-terminally acetylated Tβ4 containing 43 amino acids. Its listed molecular weight is 4963.44 g/mol and its CAS number is 77591-33-4. It is not the seven-amino-acid Ac-LKKTETQ evaluated by FDA.
Full-length Tβ4 contains 43 amino acids. LKKTETQ is its unacetylated seven-amino-acid sequence at residues 17–23. Ac-LKKTETQ is the N-terminally acetylated version of that fragment. These three materials are not interchangeable.
Full-length Tβ4 binds monomeric G-actin and regulates its availability for polymerization into F-actin. This actin-sequestering activity is relevant to research on cytoskeletal organization, cell shape, cell movement, and tissue-remodeling pathways.
Laboratory and animal studies examine full-length Tβ4 in actin dynamics, cell migration, angiogenesis, progenitor-cell activity, cardiac-cell migration, and tissue-repair models. Researchers should confirm which molecular form each study used before comparing results.
Not automatically. The seven-amino-acid fragments and full-length 43-amino-acid Tβ4 differ in size, structure, and evidence base. Results should be attributed only to the exact molecular form tested in the study.
TB-500 is not FDA-approved. In July 2026, PCAC voted 8–6, with one abstention, to recommend TB-500 free base and acetate for the 503A Bulks List. This positive advisory recommendation concerned Ac-LKKTETQ, not full-length Tβ4.
Store the unopened vial at −20°C, sealed, dry, and protected from light. For storage up to 24 months, use −80°C. Let the sealed vial reach room temperature before opening to reduce condensation. See the Storage tab.
Compare the vial label with the listed sequence, molecular weight, CAS number, formula, and strength. Then open the COA tab and select the third-party report matching the 2 mg, 5 mg, or 10 mg vial.
They are different experimental peptides. Full-length Tβ4 contains 43 amino acids and is studied in actin regulation and cell migration. BPC-157 contains 15 amino acids and has a separate preclinical evidence base. Co-mention does not establish a validated combination.
Yes. WADA lists thymosin beta-4 and its derivatives, including TB-500, on the Prohibited List. This applies to athletes and other participants subject to anti-doping rules.
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