Compound Profile
TB 500
Synthetic thymosin beta-4 fragment
TB 500 is a synthetic fragment of thymosin beta 4 marketed for muscle recovery and connective tissue repair; the underlying Tβ4 biology has real scientific grounding, but the synthetic fragment sold as TB 500 has thin direct human evidence and an unresolved FDA compounding status pending July 2026 PCAC review.
Use extra caution — No controlled human safety data exists for the synthetic TB 500 fragment. Details
At a glance
From this profile's structured data- Evidence
- Grade D
- Safety
- No controlled human safety data exists for the synthetic TB-500 fragment.
- Profile context
- Actin (G-actin) Binding, Cell Migration Promotion, Angiogenesis Support
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Unapproved compound: FDA safety and compounding review
TB-500 is not FDA-approved for human use. FDA’s Pharmacy Compounding Advisory Committee discussed the thymosin-beta-4 fragment on July 23, 2026; that advisory process does not itself create an approved drug or a final 503A bulks-list status.
- FDA says it has not identified human exposure data for the TB-500 fragment in its current compounding safety review.
- This profile is not a self-treatment guide.
- A research-use label does not establish FDA-reviewed identity, quality, safety, or effectiveness for human use.
Regulatory status
2026 federal and state regulatory context
Not FDA approved for human use; RUO labeled product is not legally intended for human consumption.
Regulatory changelog
- 2023 04/2026: FDA Category 2 restricted (503A bulk substances), alongside BPC 157 and 17 other peptides. 2026 04: Removed from Category 2 (gray zone). 2026 07 23: On FDA PCAC agenda alongside BPC 157, KPV, and MOTS C for formal 503A eligibility review.
Quick stats
- Evidence level
- Preliminary evidence
- Typical onset
- Varies by prep
- Safety rating
- Use extra caution: Use caution
- Best for
- Actin (G Actin) Binding, Cell Migration Promotion, Angiogenesis Support
- Avoid / review if
- Pregnancy/Breastfeeding, Unsupervised RUO Product Use Without Physician Oversight, No Established Pharmacokinetic Drug Interaction Data Exists
Safety
Safety & Cautions
No controlled human safety data exists for the synthetic TB 500 fragment. Because Tβ4 supports angiogenesis and cell migration broadly, some researchers urge caution in anyone with a personal or family history of cancer, though this has not been demonstrated for TB 500 in humans.
High caution
Caution level: High. Multiple caution categories apply, or the record uses avoid/contraindication language.
- Interaction-AwareMedication or interaction context is explicitly noted.
- Pregnancy/Breastfeeding CautionPregnancy or breastfeeding caution language is present.
Evidence Summary
Profile-wide ·D PreliminaryEvidence lens
Early signal that needs stronger human replication before practical claims.
Human clinical evidence: Not the primary signal
Mechanistic / preclinical: Mechanism mapped — Actin (G Actin) Binding · Cell Migration Promotion · Angiogenesis Support
Research maturity: Theoretical / mechanistic research — Mechanistic or unresolved evidence is kept separate from established human outcomes.
Safety boundary: Safety note available — No controlled human safety data exists for the synthetic TB 500 fragment.
Confidence estimate based on the design quality and consistency of published clinical trials.
TB 500 has a preliminary evidence rating.
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
How TB 500 Works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How TB 500 Works
Dosing
- No standardized dose
- No established consumer dosing protocol; see full guide article for regulatory and safety context.
Mechanisms & biological pathways
Preclinical mechanism details from scientific profiles; these represent plausible pathways but do not guarantee clinical efficacy in humans.
- Actin (G Actin) Binding
- Cell Migration Promotion
- Angiogenesis Support
- Anti Fibrotic Signaling
- Cell Migration
- Angiogenesis
Compare & Sourcing
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Direct product recommendations and affiliate links are suppressed for this compound due to its high caution or needs-review safety classification.
Evaluate the safety checks, contraindications, and potential medication interactions above under clinician supervision before use.
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
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Compound profile context
How to interpret TB 500
TB 500 compound profile with evidence context, key research topics, source notes, safety context, and references presented in an evidence-first format. Use this compound profile to understand mechanism, evidence quality, and practical safety context before comparing products or building a stack. A biochemical pathway connection can be useful for discovery, but it is not the same as proven benefit in humans.
When reviewing TB 500, separate the active molecule from the product category around it. Dose form, absorption, extract standardization, medication interactions, and individual sensitivity can change the real-world risk-benefit picture.
For supplement planning, avoid combining multiple compounds with overlapping sedating, stimulating, serotonergic, blood-pressure, anticoagulant, or liver-metabolism effects unless a qualified clinician has reviewed the context.