At a glance
- TB-500 (thymosin beta-4 fragment) is not an FDA-approved drug: Drugs@FDA has no record of it.
- It was on FDA's Category 2 safety-risk list until the nomination was withdrawn. A withdrawal is not an approval.
- PubMed lists 40 publications mentioning it, including 0 randomized controlled trials and 8 animal-only studies.
- ClinicalTrials.gov lists 1 registered study testing it (1 active).
- FDA's adverse event system (FAERS) holds 1 report mentioning it; 1 classified as serious. Reports do not prove causation.
Research topics
Most frequent MeSH subject headings in the latest PubMed records (English, as indexed).
Regulatory status
Drugs@FDA applications
No application found in Drugs@FDA, FDA's database of approved drugs.
Source: Drugs@FDA (openFDA) · verified October 30, 2026 · API query
FDA compounding safety list
FDA's stated risk · Original FDA text (English) Compounded drugs containing thymosin Beta-4, Fragment (LKKTETQ) may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation as well as peptide-related impurities. FDA has not identified any human exposure data drug products containing Thymosin Beta-4, Fragment. FDA lacks important information regarding any safety issues raised by this drug, including whether it would cause harm if administered to humans. Source: FDA.gov — Category 2 bulk drug substances · verified October 30, 2026
Removal of a substance from a regulatory list does not mean it has been approved. A "research use only" label does not make a product safe or legal for human use.
Scientific publications
Counts are PubMed records that mention the peptide in the title or abstract. Categories overlap, and a mention is not the same as testing the peptide as a treatment. Each number opens the exact PubMed search. Effects seen in laboratory or animal studies may not occur in humans. A registered clinical trial does not show that a substance is effective or safe.
Latest publications
- Investigational Peptides in Orthopaedic Practice: Evidence, Safety, and Patient Counseling for BPC-157, Thymosin Beta-4, and TB-500.
- Case Report: Regenerative peptides for Inferior alveolar nerve injury: a narrative review with hypothesis-generating three clinical cases.
- Dangers of Injectable Peptides and Other Unregulated "Biohacking" Drugs.
- Synthetic Peptides in Pharmacy Compounding: Analysis of PCAC Recommendations and Industry Safety Standards.
- Peptides in Regenerative Medicine: A Comprehensive Review of Clinical Applications in Tissue Repair and Chronic Pain Management.
- Peptide Supplements and Their Therapeutic Applications in Sports Medicine.
- Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study.
- Rapid and harmonized analytical workflow for the determination of peptidic and non-peptidic doping agents in dried and liquid blood matrices.
- Therapeutic peptides in gerontology: mechanisms and applications for healthy aging.
- Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
Source: PubMed (NCBI) · verified October 30, 2026
Clinical trials
- Registered
- 1
- Active
- 1
- With posted results
- 0
Conditions studied
| Study | Status | Phase | Start |
|---|---|---|---|
| TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable ASCVD | Recruiting | Phase 1, Phase 2 | February 5, 2026 |
All 1 study on ClinicalTrials.gov ↗
Source: ClinicalTrials.gov · verified October 30, 2026
Adverse event reports
- Reports
- 1
- Serious
- 1
- With death outcome
- 0
Most reported reactions
Adverse event reports do not prove that the substance caused these effects. Side effects not listed here may still occur. Reaction terms are MedDRA terms as reported to FAERS.
Source: FDA FAERS (FAERS data as of July 30, 2026) · verified October 30, 2026 · API query
Change history
No changes since monitoring began on October 30, 2026.