TB-500 (Thymosin Beta-4, 43 aa) Research Peptide

Every batch ships straight from the lab that synthesises it — sealed, tamper-evident, and verified to >99% HPLC purity with a published batch Certificate of Analysis. View the batch Certificate of Analysis → Buying direct means you pay the lab-direct rate on every vial, with nothing stacked on top.

Order a sealed 10-vial research pack , or add a single-vial laboratory sample alongside your pack to evaluate a compound at smaller scale first. Same source, same purity specification — scaled to whatever your research needs.

What It's Researched For

In plain terms, TB-500 here is the full-length thymosin beta-4 peptide. These are the laboratory topics the published literature covers.

Actin biology

Tβ4 is a standard subject in studies of G-actin binding and the control of actin polymerisation.

Cell migration assays

Cell-based work examines how Tβ4 relates to the movement of endothelial and epithelial cells.

Structure-function mapping

Short sequences within the 43 residues, such as LKKTETQ and Ac-SDKP, have been studied for distinct activities.

Peptide characterisation

A 43-residue, intrinsically disordered, N-acetylated peptide used as an analytical reference subject.

Overview

In short: TB-500 is supplied as full-length thymosin beta-4 (Tβ4), a 43-amino-acid N-acetylated peptide encoded by the human TMSB4X gene.

Key research facts

Full-length 43-residue thymosin beta-4 sequence, listed in one-letter and three-letter code

N-terminal acetylation matching the natural mature peptide (N-acetylserine, UniProt P62328)

Contains the LKKTETQ actin-binding motif at residues 17-23

Described in the literature as the major actin-sequestering molecule of eukaryotic cells

These points summarise lab themes, not human outcomes.

The mature human sequence, taken from UniProt entry P62328, is Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES. The precursor begins with a methionine that is removed, and the UniProt record lists N-acetylserine at the new first residue. Residues 17-23 (LKKTETQ) make up the central actin-binding motif; Sosne et al. describe it as aa 17-23 of the 43-residue protein (FASEB J, 2010; PMID 20179146).

Tβ4 is reviewed as the major actin-sequestering molecule in eukaryotic cells and is found in essentially all cells and body fluids (Sosne et al., 2010; Goldstein et al., 2005). Short sub-sequences, including the N-terminal Ac-SDKP and the LKKTETQ region, have each been examined on their own in the literature, which is why they are mentioned here as parts of the whole peptide.

This page cites published laboratory and review literature only. No controlled human data are cited here. The material is not approved for human use and is sold for in-vitro research only.

Mechanism of Action

In the cited literature, Tβ4 binds monomeric actin through a central motif and has been associated with several cell-level activities attributed to separate regions of the peptide.

Pathway Effect Why it matters G-actin binding Binds monomeric actin; described as the major actin-sequestering molecule of eukaryotic cells Relevant to how the pool of polymerisable actin is regulated in cells Actin-binding motif (residues 17-23) LKKTETQ is the central actin-binding domain UniProt records that substitutions at residues 12, 16 and 18 weaken actin binding in mutagenesis work N-terminal Ac-SDKP region Residues 1-4 of the mature chain form the tetrapeptide Ac-SDKP Examined in the literature as a separate active site Reported gene-expression effects Review literature lists induction of laminin-5, MMPs, TGF-beta and zyxin expression Reported in cell systems; not localised to a single region of the peptide

Deeper dive for scientific readers

Sosne and colleagues (FASEB J, 2010) review active sites in short sequences of Tβ4, placing the central actin-binding domain at aa 17-23 and the N-terminal Ac-SDKP at the amino terminus. Goldstein and colleagues (Trends Mol Med, 2005; Expert Opin Biol Ther, 2012) review the molecular properties of the peptide. Malinda and colleagues reported on wound-healing experiments with Tβ4 in animal models (J Invest Dermatol, 1999). These are literature descriptions of what was studied, not claims about this product.

Common Questions People Are Asking

What is TB-500 on this site?

It is supplied as full-length thymosin beta-4 (Tβ4): a 43-amino-acid, N-acetylated peptide with the human sequence Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES (UniProt P62328).

Is this the 7-amino-acid LKKTETQ fragment?

No. LKKTETQ (residues 17-23) is the central actin-binding motif inside the 43-residue peptide. The product is the whole chain, not that segment.

What is the molecular weight and formula?

PubChem lists thymosin beta 4 (CID 45382195) with the formula C212H350N56O78S and an average molecular weight of 4963 Da.

Is the peptide acetylated?

Yes. UniProt P62328 records N-acetylserine at the first residue of the mature chain after the initiator methionine is removed.

What does the literature say about its biology?

Reviews describe Tβ4 as the major actin-sequestering molecule of eukaryotic cells, with the central actin-binding domain at residues 17-23 and the Ac-SDKP site at the N-terminus. These are laboratory descriptions, not statements about human effects.

Are there human data?

No controlled human data are cited on this page, and human safety is not established.

Does New-U give dosing or administration guidance?

No. This material is for laboratory research only and no amount, schedule or administration guidance is published.

Is TB-500 approved for human use?

No approval for human use is claimed. It is sold as a research chemical, not for human or veterinary use.

How should the research material be stored?

Store the lyophilised powder frozen and protected from light, and follow the batch-specific handling documentation.

What vial sizes are offered?

New-U lists TB-500 as 10-vial packs at 2 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg, 50 mg or 60 mg per vial, and as single sample vials at 5 mg and 10 mg; see the pricing table on this page.

Where can I buy TB-500?

Right here - TB-500 is supplied directly by New-U Research Compounds on this page. Every batch is independently third-party tested to >99% HPLC purity with a batch-linked Certificate of Analysis, supplied as lyophilised research-grade material, and shipped direct from source worldwide in discreet, tracked packaging.

How much does TB-500 cost?

TB-500 pricing is shown live on this page, per pack size - 10-vial research packs as standard, with single-vial sample options on selected compounds. The batch Certificate of Analysis is published on this page, and shipping is free on orders over $350.

Is TB-500 third-party tested?

Yes. Every TB-500 batch is verified by independent laboratories (Janoshik Analytics and Freedom Diagnostics) for identity and purity, with a batch-linked Certificate of Analysis confirming >99% HPLC purity. Current batch certificates are published on this page and on our COA page rather than packed with orders. View the TB-500 Certificate of Analysis →

How do I buy TB-500?

Add the TB-500 pack size you need to your cart and check out: enter your shipping details, then choose your payment method - cryptocurrency or card - on the next step. The batch Certificate of Analysis (COA) is published on this page, so you can check it before you order.

What payment methods can I use to buy TB-500?

At checkout you can pay by card or crypto. New-U supports BTC and selected stablecoin and network-asset payments across Ethereum, Solana, TRON, Polygon, Base, BNB Chain and Linea. You choose your method after confirming your order.

How fast is shipping, and do you ship worldwide?

Yes - we ship worldwide in discreet, unmarked, tracked packaging; lyophilised peptides are stable through the tracked transit window. Delivery typically takes 6–14 business days, and shipping is free on orders over $350.

Is it legal to buy TB-500?

In the United States, TB-500 is sold strictly for laboratory and research purposes only. It is not approved by the FDA for human consumption and is not sold for that purpose. Regulatory status varies by jurisdiction - buyers are responsible for compliance in their own region.

Research use only - all claims made on this site are for testing and research use only.

Pharmacokinetics

Half-life Not stated; no figure is cited for the full-length peptide on this page Absorption route Not stated; no figure is cited on this page Metabolism / clearance Not stated; no figure is cited on this page Stability Lyophilised material stored frozen and protected from light; handle reconstituted material cold per batch-specific documentation Notes Average molecular weight 4963 and formula C212H350N56O78S are PubChem values for thymosin beta 4 (CID 45382195). UniProt describes the chain as disordered.

Research-Observed Effects

Binding of monomeric actin through the central LKKTETQ motif (residues 17-23)

Weakened actin binding when residues 12, 16 or 18 are substituted (UniProt mutagenesis annotations)

Reported induction of laminin-5, MMP, TGF-beta and zyxin expression in cell systems (review literature)

Wound-healing experiments in animal models (Malinda et al., 1999)

Published Research Context

New-U does not provide dosing, schedule, administration, cycle-planning or performance-use guidance for this material. Experimental parameters in published studies vary by model and are not a recommendation.

Side Effects (Observed in Literature)

Common

No safety data for this material are cited on this page; human safety is not established

Dose-dependent

No controlled human data are cited; no dose-response information is provided

Evidence Tier

Overall: Tier 2: Animal / preclinical

The sources cited on this page are laboratory and review literature. No controlled human data are cited here, and no regulator approval for human use is claimed.

Tier 2 · Animal

Malinda et al., Journal of Investigative Dermatology, 1999 (PMID 10469335): thymosin beta4 wound-healing experiments in animal models

Certificates, databases & peer-reviewed sources

Last reviewed: 14 October 2026 · New-U Research Compounds

Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999. PMID: 10469335. · 1999

Goldstein AL, Hannappel E, Kleinman HK. Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 2005. PMID: 16099219. · 2005

Sosne G, Qiu P, Goldstein AL, Wheater M. Biological activities of thymosin beta4 defined by active sites in short peptide sequences. FASEB J. 2010. PMID: 20179146. · 2010

Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012. PMID: 22074294. · 2012

PubMed: peer-reviewed literature on TB-500

ClinicalTrials.gov: registered studies on TB-500

TB-500: Wikipedia

WebMD: consumer health reference

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Key Characteristics

Full-length thymosin beta-4: 43 amino acids

N-terminally acetylated (N-acetylserine, UniProt P62328)

Human TMSB4X gene product

Actin-binding motif LKKTETQ at residues 17-23

Average molecular weight 4963 Da, formula C212H350N56O78S (PubChem)

Supplied as lyophilised research material

Specifications

Compound Name TB-500 (full-length thymosin beta-4, Tβ4) Source Organism of Sequence Homo sapiens (UniProt P62328, TMSB4X) Length 43 amino acids N-terminus Acetylated (N-acetylserine) Sequence (one-letter) Ac-SDKPDMAEIE KFDKSKLKKT ETQEKNPLPS KETIEQEKQA GES Sequence (three-letter) 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 Actin-Binding Motif LKKTETQ, residues 17-23 of the 43-residue chain Molecular Formula C 212 H 350 N 56 O 78 S Molecular Weight 4963 Da (average) Physical Form Lyophilised powder Storage Store lyophilised material frozen and protected from light. Follow batch-specific handling documentation. Research Format Lyophilised peptide material for qualified laboratory research only. Not supplied for human or veterinary administration. Use Classification Research chemical. Not for human or veterinary use.

About TB-500: Full-Length Thymosin Beta-4 Reference

The TB-500 sold here is the complete thymosin beta-4 peptide, not a short fragment. Its 43 residues begin with an acetylated serine and end with serine, and the whole chain is listed on this page in one-letter and three-letter code so it can be compared with the UniProt P62328 record.

Inside the chain, residues 17-23 (LKKTETQ) are the central actin-binding motif, and residues 1-4 form the tetrapeptide Ac-SDKP. Both are parts of the same molecule. Anything the literature attributes to a short synthetic piece of Tβ4 should not be read as describing this full-length material, and vice versa.

New-U Research Compounds supplies this material as a lyophilised powder strictly for in-vitro and laboratory research. No controlled human data are cited on this page.

Thymosin beta-4: general background (Wikipedia)

UniProt P62328: Thymosin beta-4, Homo sapiens

PubChem CID 45382195: Thymosin Beta 4

Customer Reviews

Good first order

My first TB-500 order from New-U went well. Confirmation came through, tracking updated and the vial arrived properly packed.

- Leo B***** · 14 September 2026

COA access helped

The COA being available before checkout made the TB-500 order feel more transparent. Batch code was easy to match once it arrived.

- Marta N**** · 14 September 2026

Clean and simple

The TB-500 order was not overcomplicated. Clear product info, easy checkout, sealed vial and readable batch code. That was enough for me.

- Isla G**** · 14 September 2026

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TB-500 vs related Healing / Recovery compounds

Compound Price Purity spec COA TB-500 from $119 >99% HPLC 1 published batch BPC-157 from $70 >99% HPLC 1 published batch AOD-9604 from $97 >99% HPLC 1 published batch

TB-500 vs BPC-157 - full comparison

Descriptive catalog comparison for research sourcing decisions - not dosing guidance.

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Research guide TB-500 research guide In the cited literature, Tβ4 binds monomeric actin through a central motif and has been associated with several cell-level activities… Read the guide →

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Analytical evidence View the TB-500 COA Latest published certificate of analysis (purity and identity), dated 2026-01-29. View the COA →

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Research peptides. Third-party Certificates of Analysis (Janoshik Analytical & Freedom Diagnostics) are published on the website. Supplied strictly for laboratory research use.

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