Evidence brief
TB-500
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Direct answer
No FDA-approved TB-500 drug product.
A seven-amino-acid piece of thymosin beta-4 promoted for repair, without reliable human healing evidence and with major product and anti-doping limits.
- How strong is the evidence?
- Insufficient
Reliable studies in people are missing, too limited, or do not support the claim. This does not prove that the substance has no effect on the body. - What evidence exists?
- Preclinical or formulation evidence
The research used cells, animals, or product-form tests. It does not establish benefit or safety in people. - Sports rules
- Prohibited
The checked rules list this substance or group as prohibited under the stated conditions. Check the current rules for your sport.
Reviewed August 1, 2026. Sources and update notes are below.
No sales or dosing advice. This guide explains research. It was not independently medically reviewed, and it does not diagnose, prescribe, or recommend treatment.
Also known as TB500 · Ac-LKKTETQ · thymosin beta-4 fragment 17-23
Part of Healing and recovery peptides
Compared with BPC-157
Words used here
- preclinical
- research in cells, tissues, or animals before or outside testing in people
- formulation
- the ingredients and physical form of the finished product
- molecule
- one specific chemical substance
- mechanism
- how a substance may cause a body change
- biomarker
- a body or lab measurement, not automatically a health benefit
- outcome
- what the study measured
- amino acid
- a small building block that makes peptides and proteins
- indication
- the approved or studied use and patient group
More detailProduct and study details
01 · Evidence profile
Four questions about the evidence
FDA found no adequate human clinical outcome evidence for compounded TB-500 wound-healing use.
Fragment identity and laboratory findings do not establish a clinical benefit in people.
Human exposure and product-specific safety information are inadequate.
Nomenclature, salt form, purity, sterility, and fragment-versus-protein distinctions create major uncertainty.
02 · Identity
What it is
TB-500 is reported as a seven-amino-acid piece, or fragment, of thymosin beta-4. It is not full-length thymosin beta-4, and evidence about the full protein cannot automatically be transferred to the fragment.
Scientific group: Synthetic thymosin beta-4 fragment. This group name describes the type of molecule or body signal. It does not prove a benefit, safety, or approval.
03 · Exact product
The molecule is not the finished product.
Formulation: The finished product's ingredients and physical form. Route: How the product enters the body. Indication: The approved or studied use and group of people for a product.
None identified in the United States.
- No FDA-approved indication
04 · Research results
What the research shows
FDA has published a detailed 2026 briefing on TB-500's identity, characterization, proposed wound-healing use, and evidence gaps. WADA explicitly names TB-500 on the 2026 Prohibited List.
Reliable controlled studies in people do not establish faster tendon, muscle, or wound healing from TB-500. Safety, purity, sterility, long-term effects, and equivalence of marketed material remain uncertain.
Exact product
TB-500 is not the same as the full thymosin beta-4 molecule. FDA identifies TB-500 as a seven-amino-acid fragment, not as interchangeable with full-length thymosin beta-4. Internet naming and certificates do not establish product identity or clinical equivalence.
05 · Claim check
Claims I checked
3 claims checked for this brief.
“TB-500 is the same thing as thymosin beta-4.”
FDA describes TB-500 as a seven-amino-acid fragment of the much larger thymosin beta-4 molecule.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- Chemical identity, not a claim about all possible biological activity. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“TB-500 accelerates tendon and muscle healing in people.”
The FDA evidence review did not identify adequate human outcome evidence for wound-healing use.
- Evidence used
- No reliable human outcome evidence. No reliable study in people shows the health outcome in this statement.
- Limits of this answer
- Clinical tendon, muscle, and wound-healing outcomes in people. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“TB-500 is allowed in tested sport.”
TB-500 is named on the current WADA Prohibited List.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- Sport governed by the World Anti-Doping Code. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
06 · Questions
Questions people ask about TB-500
No FDA-approved TB-500 drug product. No approved product is identified in the United States.
Prohibited. TB-500 is named as a prohibited thymosin-beta-4 derivative on the 2026 WADA Prohibited List and is prohibited at all times for covered athletes. This status is not personal clearance to compete.
FDA has published a detailed 2026 briefing on TB-500's identity, characterization, proposed wound-healing use, and evidence gaps. WADA explicitly names TB-500 on the 2026 Prohibited List.
Reliable controlled studies in people do not establish faster tendon, muscle, or wound healing from TB-500. Safety, purity, sterility, long-term effects, and equivalence of marketed material remain uncertain.
07 · Safety
Safety limits for this record
This is not an invitation to experiment. The guide provides no sourcing, reconstitution, injection, cycle, stack, or injury-treatment instructions.
TB-500 is named as a prohibited thymosin-beta-4 derivative on the 2026 WADA Prohibited List and is prohibited at all times for covered athletes.
The checked rules list this substance or group as prohibited under the stated conditions. Check the current rules for your sport.
Reviewed .Check current rules for tested sport ↗Open the governing record ↗08 · Sources
Read the sources
09 · Review history
Review history
Revalidated TB-500 against the 2026 WADA Prohibited List, where TB-500 and thymosin-beta-4 are named in the prohibited growth-factor category.
Initial brief uses FDA's July 2026 identity and evidence review before final agency action.
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Not independently medically reviewed. This page is not a dosing, sourcing, or treatment guide.