TB500 Fragment (Frag 17-23)

N-acetylated thymosin-β4 residues 17–23 research fragment · not full-length thymosin-β4

Lot-specific chromatographic purity plus quantitative peptide content; confirm N-acetylation, terminal form, counterion, water and related peptides separately · target, verify batch COACAS 885340-08-9RUO

Research statusFragment-specific preclinical and analytical evidence is limited; much cited clinical evidence concerns full-length thymosin-β4, not this fragment

Supplied formLinear N-acetylated heptapeptide corresponding to thymosin-β4 residues 17–23

Lead timeConfirmed with quote

TB500 Fragment (Frag 17-23) — Lot-specific lyophilized research peptide; confirm colour and physical form on the released-lot COA

TB500 Fragment (Frag 17-23) — Lot-specific lyophilized research peptide; confirm colour and physical form on the released-lot COA · Representative packaging image · verify the ordered lot

Representative packaging image · verify the ordered lot

Decision summary

Key benefits

Defensible research value includes actin-related mechanism hypotheses, fragment-versus-parent comparisons, cell-migration and wound-model experiments, analytical identification and anti-doping method development
Claims of systemic tissue repair, athletic recovery, angiogenesis or clinical wound benefit are not established for this isolated fragment and must remain hypotheses or parent-molecule background.

Published research context is presented for literature orientation only. It is not a dosing, treatment or human-use instruction.

Qualification data

Specifications to confirm against the released lot

CAS: 885340-08-9
Formula: C₃₈H₆₈N₁₀O₁₄
Molecular weight: 889.0 g/mol
Appearance: Lot-specific lyophilized research peptide; confirm colour and physical form on the released-lot COA
Purity: Lot-specific chromatographic purity plus quantitative peptide content; confirm N-acetylation, terminal form, counterion, water and related peptides separately · target, verify batch COA
Storage: Follow the released-lot label, COA and fragment-specific stability data. Do not assume 2–8°C storage, a 28-day reconstituted period or finished-formulation instructions without supporting data for the supplied terminal form, counterion, matrix and container.
MOQ: On request
Lead time: Confirmed with quote

PubChem CID 62707662

Qualification matrix

Identity, purity and content are separate release questions.

Identity

Confirm the stated molecule and supplied form. Start with the matching batch COA; request sequence-level evidence only when the buyer's written procedure requires it and availability or a separate scope has been agreed.

Purity

Review RP-HPLC method conditions, wavelength, integration and related-peak handling. A percentage without the method is not enough.

Content

Net peptide content is not the same as gross lyophilized powder weight. Ask which assay supports the stated amount and whether water/counter-ion is addressed.

Stability

Define long-term storage and transit exposure separately. Cold-chain can be quoted when the buyer’s risk assessment requires it and adds cost.

Research context

What researchers study about TB500 Fragment (Frag 17-23)

This record defines TB500 Fragment (17–23) as N-acetylated Ac-LKKTETQ, a seven-residue sequence corresponding to thymosin-β4 residues 17–23. It is the same chemical identity represented by this catalogue’s TB-500 seven-residue entry, but distinct from full-length 43-residue thymosin-β4 and RGN-259. Commercial names are ambiguous, so sequence, N-acetylation and mass must control identity. No genuine registered human trial of the isolated fragment was identified; NCT07487363 explicitly describes itself as fictional example data and is not evidence.

Appropriate laboratory contexts include fragment identity and N-acetylation, actin-related assays, fragment-versus-full-length comparisons, cell migration and repair models, proteolytic stability, formulation and analytical anti-doping research
No approved clinical indication applies to this fragment.

Mechanism context

The question the literature is testing

The LKKTETQ region is associated with actin-binding biology in the thymosin-β4 literature, but isolating and N-acetylating seven residues can change conformation, stability, distribution and potency. Parent-protein mechanisms cannot establish equivalent systemic action of the fragment. Experimental interpretation requires authenticated full-length and fragment controls, defined concentration, matrix and quantitative recovery.

Evidence map

Research routes and exposure context

Evidence tierMixed evidence context

Research areaRepair and regenerative research

Routes reported in sources

No administration route applies

Dose / exposure contextProtocol-specific; verify the cited primary source

Routes and exposure contexts summarize cited studies or approved finished-product labels. They are not instructions for administering this RUO material; no customer dose is provided.

Evidence boundaries

Compatibility, limitations and decision context

Not for human or veterinary administration
Controlled human safety data for the isolated fragment were not identified, and full-length thymosin-β4 experience cannot establish fragment safety
Identity confusion, incorrect content, impurities, aggregation, contamination and unvalidated endotoxin or sterility are material risks
The 2026 WADA Prohibited List names thymosin-β4 and its derivatives, including TB-500, under S2.3.

Interactions reported in the literature

No human combination or compatibility guidance applies
Wolverine Blend, BPC-157, CJC-1295, IGF-1, ipamorelin, GHRP-6 and melanotan-II synergy claims were removed because vendor or community co-use does not establish pharmacological interaction, efficacy or safety
Laboratory mixtures require single-component controls and component-resolved analysis.

Literature context is not a supplier release result or human-use instruction. Follow your institution's approved laboratory risk assessment.

Factory batch documentation

TB500 Fragment (Frag 17-23) factory batch COAs

TB500 Fragment (Frag 17-23) 2 mg Factory batch COA protected preview

TB500 Fragment (Frag 17-23)2 mg · WHJLP-TBF2-260403-A

TB500 Fragment (Frag 17-23) 5 mg Factory batch COA protected preview

TB500 Fragment (Frag 17-23)5 mg · WHJLP-TBF5-260403-A

TB500 Fragment (Frag 17-23) 10 mg Factory batch COA protected preview

TB500 Fragment (Frag 17-23)10 mg · WHJLP-TBF10-260402-A

Representative records, refreshed periodically

Published COAs show representative factory batches and may not be the latest available. For a current quote or shipment, our sales team can confirm the applicable lot and provide its COA.

Independent testing, arranged on request

Third-party reports are not routinely published. If independent verification is required, we can agree the laboratory, method, acceptance criteria and remedy before testing. If the agreed specification is not met, an appropriate resolution—including a refund where applicable—can be discussed under the agreed terms. Unless otherwise agreed in writing, the buyer pays the cost of this optional testing.

Help reviewing your COA

Need help reading a factory COA or third-party report? Our sales team can clarify test items, specifications and how the results relate to the lot under discussion.

Ask for the current packet, not a generic certificate

Require Ac-LKKTETQ sequence and N-acetylation confirmation, intact mass, peptide mapping or tandem-MS where appropriate, chromatographic purity, quantitative peptide content, terminal and salt form, counterion, water, residual solvents, related peptides, container integrity and lot-specific stability
A clear reconstituted solution or a generic COA does not prove identity, content, sterility or stability.

Released-batch COARP-HPLC result and method contextIdentity result appropriate to the moleculeWater / counter-ion context where relevantSDS and handling statementAdditional testing scoped on request

Available fills

Quote the fill and pack configuration you need

Reference SKUFillBase pack

TBF500-02MG2 mg10 vials

TBF500-05MG5 mg10 vials

TBF500-10MG10 mg10 vials

Handling

Storage in the lab and temperature during transit are different decisions

Follow the released-lot label, COA and fragment-specific stability data. Do not assume 2–8°C storage, a 28-day reconstituted period or finished-formulation instructions without supporting data for the supplied terminal form, counterion, matrix and container.

State destination, season, acceptable transit exposure and whether your protocol requires insulated or cold-chain service. Additional temperature-control cost is quoted explicitly.

Buyer FAQ

Terms to settle before the purchase order

Can a buyer arrange third-party testing?+

Yes. Testing must be performed by a mutually accepted, established specialist laboratory. Fee allocation, specification, sampling, method and acceptance rule must be agreed before testing; if an agreed independent result shows nonconformance, the remedy follows the signed order terms. Unless otherwise agreed in writing, the buyer pays the cost of this optional testing.

Does HPLC purity prove peptide content?+

No. Chromatographic purity describes the relative peak profile under a stated method. Identity, water, counter-ion, residual solvents and assay/content may require separate methods.

Is cold-chain shipping always required?+

Not always. Heat can accelerate degradation, especially during summer and long transit. Cold-chain reduces exposure but raises cost. State the destination and stability risk so the right service can be quoted.

How are payment terms handled?+

Available methods and milestones depend on order value, destination and project type. The pro forma invoice should state currency, bank details, fees, payment milestones and the release condition.

Why must the testing laboratory understand peptide chemistry?+

Free-base and salt forms, hydrophilic and hydrophobic sequences, aggregation and adsorption can change sample preparation and method suitability. Use a laboratory experienced with the molecule class.

External qualification references

WHO good storage and distribution practices IATA Temperature Control Regulations ISO/IEC 17025 laboratory competence 21 CFR 211.84 component testing and supplier COA controls

These are buyer-qualification references, not claims that this RUO material is regulated, certified or released under those frameworks. Applicability depends on the buyer's workflow and jurisdiction.

Selected sources

Literature behind the research context

Identity: PubChem CID 62707662, sequence Ac-LKKTETQ-OH, formula C₃₈H₆₈N₁₀O₁₄, molecular weight 889.0 g/mol and CAS 885340-08-9. Analytical context: Esposito et al., Drug Testing and Analysis 2012, PMID 22962027, identified the N-acetylated fragment; Ho et al., Journal of Chromatography A 2012, PMID 23084823, detected it and metabolites in equine samples. Neither is human pharmacokinetic or efficacy evidence. Parent boundary: full-length thymosin-β4 comprises 43 residues. Anti-doping context: official 2026 WADA Prohibited List, S2.3. NCT07487363 is fictional example data and is excluded.

01
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 Testing and Analysis · 2012 · peer-reviewed original research (analytical/doping chemistry)
Open source
02
Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma by liquid chromatography-mass spectrometry
Journal of Chromatography A · 2012 · peer-reviewed original research (analytical/doping chemistry)
Open source
03
Thymosin beta4 accelerates wound healing
Journal of Investigative Dermatology · 1999 · peer-reviewed original research (landmark/foundational)
Open source
04
Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues
Trends in Molecular Medicine · 2005 · peer-reviewed review
Open source
05
Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing
Annals of the New York Academy of Sciences · 2007 · peer-reviewed clinical study report / commentary on Phase 2 RCT
Open source
06
Thymosin Beta-4 and TB-500 in Tissue Healing, Regeneration, and Musculoskeletal Repair: A Scoping Review
Applied Sciences (MDPI) · 2026 · peer-reviewed scoping review (PRISMA-ScR methodology)
Open source
07
The 2026 Prohibited List — Section S2.3
World Anti-Doping Agency · 2026 · official international anti-doping standard
Open source
08
Corporate and pipeline overview: thymosin beta 4 (Tβ4) and RGN-259
RegeneRx Biopharmaceuticals, Inc. · 2026 · company website (pharmaceutical developer of full-length Tβ4, official corporate source)
Open source

Product FAQ

Questions buyers ask about TB500 Fragment (Frag 17-23)

Is TB-500 Fragment (17–23) the same as full-length thymosin-β4?+

No. This catalogue item is the N-acetylated seven-residue fragment Ac-LKKTETQ, CAS 885340-08-9. Full-length thymosin-β4 is a 43-residue peptide and has a different identity and registry record. Require the exact sequence, terminal modification, formula and intact mass on the batch COA; do not qualify either material by the informal name alone.

What does the current anti-doping status mean for procurement?+

WADA's 2026 Prohibited List names TB-500 in class S2.3, prohibited at all times in sport. Laboratories supporting athletes, racing or regulated sports should document restricted access and verify the current governing list and local rules before ordering. The sporting classification does not by itself define a universal criminal-control schedule.

Is there registered human clinical evidence for this seven-residue fragment?+

No genuine registered human trial was identified in this review. ClinicalTrials.gov record NCT07487363 explicitly describes itself as a fictional example record and must not be cited as clinical evidence. Evidence for the isolated seven-residue fragment is mainly analytical, in vitro or animal work; findings for full-length thymosin-β4 cannot automatically be transferred to it.

TB500 Fragment (Frag 17-23)

Key benefits

Specifications to confirm against the released lot

Identity, purity and content are separate release questions.

What researchers study about TB500 Fragment (Frag 17-23)

The question the literature is testing

Research routes and exposure context

Compatibility, limitations and decision context

Interactions reported in the literature

TB500 Fragment (Frag 17-23) factory batch COAs

Ask for the current packet, not a generic certificate

Quote the fill and pack configuration you need

Storage in the lab and temperature during transit are different decisions

Terms to settle before the purchase order

Literature behind the research context

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

Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma by liquid chromatography-mass spectrometry

Thymosin beta4 accelerates wound healing

Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues

Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing

Thymosin Beta-4 and TB-500 in Tissue Healing, Regeneration, and Musculoskeletal Repair: A Scoping Review

The 2026 Prohibited List — Section S2.3

Corporate and pipeline overview: thymosin beta 4 (Tβ4) and RGN-259

Questions buyers ask about TB500 Fragment (Frag 17-23)

Compare adjacent molecules and documentation needs.

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