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Tissue biology research

TB-500 Dosage, Protocol & Research Guide

By Sam, MBA

  • MW 889 g/mol
  • CAS 885340-08-9
Dosage, protocol, reconstitution and storage reference for TB-500, with a reconstitution calculator, vial sizes and cited research.

Reconstitution calculator

Sizes in published sources5 mg10 mg

Calculator example, not a recommended amount

Concentration
2.5 mg/mL
Volume to draw
0.1 mL
Units on a U-100 syringe
10 units

0102030405060708090100

Properties

CAS
885340-08-9
Molecular weight
889 g/mol
Formula
Not yet recorded
Sequence
Ac-LKKTETQ
Aliases
Thymosin Beta-4 fragment, Ac-LKKTETQ
Vial sizes (mg)
5, 10

Storage

Lyophilised (dry powder)

-20 °C; supplied as a solid (Cayman Chemical TB-500 (acetate), item 45081).[5]

Source

Storage notes

Lyophilized
Not yet recorded from a cited source
Reconstituted stability (days)
Not yet recorded from a cited source

Side effects, contraindications and regulatory status

Reported side effects

  • Identity: no human safety data located for the TB-500 fragment (Ac-LKKTETQ). FDA states it has not identified human exposure data for fragment (LKKTETQ) products and cites immunogenicity risk from aggregation and impurities (page current 2026-04-22).[1] Regulator or expert-panel statement
  • Full-length thymosin beta-4 (not the TB-500 fragment), intravenous in healthy volunteers, 42 to 1260 mg single dose then daily for 14 days: adverse events were infrequent and mild or moderate; no dose-limiting toxicity or serious adverse events (Ann N Y Acad Sci 2010).[4] Human trial
  • Full-length thymosin beta-4 (not the TB-500 fragment), topical, 73 venous stasis ulcer patients: the authors report the safety profile of all doses was deemed acceptable and comparable to placebo (Ann N Y Acad Sci 2010).[2] Human trial
  • Full-length thymosin beta 4 (RGN-259), 0.1% eye drops for 28 days in 72 dry eye subjects: no adverse events were observed (Clin Ophthalmol 2015). Ophthalmic route, not the TB-500 fragment.[6] Human trial
  • Scoping review (Am J Sports Med 2026) of BPC-157, thymosin beta-4 or TB-500 and four other peptides: human studies were a handful, most lacking robust controls; the authors cite absent efficacy or safety data for many emerging peptides.[7] Observational

Cautions from reviews and trials

  • Review cautions: the 2026 Am J Sports Med scoping review (BPC-157, thymosin beta-4 or TB-500, GHK-Cu and others) says these peptide supplements should not currently be recommended as a replacement or adjunct for existing orthopaedic standard of care.[7] Observational

Regulatory status

Thymosin beta-4 fragment (LKKTETQ), TB-500, is listed in the 'nominated but withdrawn' table of the FDA safety-risk page (current 2026-04-22); not full-length thymosin beta-4. Checked 2026-10-20.[1] Source

Report any adverse reaction to a qualified healthcare professional.

What the research says

Summaries of the cited studies, each with its evidence grade.

  • pubmed.ncbi.nlm.nih.gov[2]

    Human trial human

    Phase 2 double-blind placebo-controlled dose-escalation study of topical full-length thymosin beta 4 (not the TB-500 fragment) in 73 venous stasis ulcer patients (Ann N Y Acad Sci 2010, doi 10.1111/j.1749-6632.2010.05490.x); the abstract names a 0.03% dose

    Human clinical trial

  • pubmed.ncbi.nlm.nih.gov[3]

    Human trial human

    Phase 2 randomized double-masked trial of full-length thymosin beta 4 eye drops (RGN-259 0.1%, not the TB-500 fragment) versus vehicle in 9 patients with severe dry eye (Cornea 2015, NCT01393132): 6 times daily for 28 days

    Human clinical trial

  • pubmed.ncbi.nlm.nih.gov[4]

    Human trial human

    Randomized placebo-controlled study of intravenous full-length synthetic thymosin beta 4 (not the TB-500 fragment) in healthy volunteers (Ann N Y Acad Sci 2010): 4 ascending cohorts of 10 subjects at 42, 140, 420 or 1260 mg as a single dose, then the same dose daily for 14 days after safety review

    Human clinical trial

Frequently asked questions

How is lyophilised TB-500 stored?

Cited storage for the lyophilised vial: -20 °C; supplied as a solid (Cayman Chemical TB-500 (acetate), item 45081)..

What is the regulatory status of TB-500?

Thymosin beta-4 fragment (LKKTETQ), TB-500, is listed in the 'nominated but withdrawn' table of the FDA safety-risk page (current 2026-04-22); not full-length thymosin beta-4. Checked 2026-10-20.

Compound facts

Recorded molecular weight: 889 g/mol.
Recorded CAS number: 885340-08-9
Not yet recorded from a cited source.

Sources

https://pubchem.ncbi.nlm.nih.gov/compound/62707662
PubMed IDs
Not yet recorded

References

Numbered sources used on this page. Markers in the text link here.

  1. fda.gov Regulator or expert-panel statement
  2. pubmed.ncbi.nlm.nih.gov Human trial
  3. pubmed.ncbi.nlm.nih.gov Human trial
  4. pubmed.ncbi.nlm.nih.gov Human trial
  5. caymanchem.com Manufacturer documentation
  6. pubmed.ncbi.nlm.nih.gov Human trial
  7. pubmed.ncbi.nlm.nih.gov Observational