TB-500 is not thymosin beta-4, and the human evidence is missing.
Online claims often combine a seven-amino-acid TB-500 fragment with studies of full-length 43-amino-acid thymosin beta-4. FDA says they are not the same substance and identified no study that administered TB-500 to people. This guide keeps identity, evidence, safety, and product status separate.
The thymosin beta-4 trial record does not cross the TB-500 identity boundary.
FDA identifies TB-500 as an N-acetylated fragment with seven amino acids. Full-length thymosin beta-4 has 43 amino acids. FDA explicitly states that TB-500 and thymosin beta-4 are not the same substance.
FDA found no clinical studies or other human exposure data for TB-500 free base or TB-500 acetate by any route. Human thymosin beta-4 trials are useful contrast records, but they cannot establish TB-500 benefits, side effects, dosage, or safety.
Read the TB-500 record in four fields.
This is a sourced status snapshot, not a safety score, treatment recommendation, or seller certification. Each field links back to the detailed record below.
0 direct human studies
FDA found no administered human evidence for TB-500 free base or acetate.
Inspect the human evidenceNo proven clinical benefit
Full-length thymosin beta-4 studies cannot establish TB-500 healing, recovery, or safety.
Audit the popular claimsNo FDA-approved product
TB-500 is a seven-amino-acid fragment, not an approved thymosin beta-4 medicine.
Check status and destination routesDated US price boards
Two related names, two different substances, and no transferable human result.
Before interpreting any study, match the exact sequence, length, modification, formulation, route, and product. Shared origin or overlapping amino acids do not make two interventions interchangeable.
7 amino acids
Synthetic N-acetylated fragment corresponding to thymosin beta-4 residues 17 through 23, with sequence LKKTETQ. FDA found no human administration study.
Open the FDA identity review →43 amino acids
Full-length peptide studied in topical, ophthalmic, injectable, and recombinant products. Those records answer questions about their exact interventions, not TB-500.
Open a full-length trial record →Match the intervention
A full-length thymosin beta-4 paper, an LKKTETQ metabolite result, and a seller-labelled TB-500 vial are three different records. None authenticates the others.
Check product evidence fields →Identity, laboratory findings, human studies, and approval are separate questions.
The right question is not whether related research exists. It is whether the exact TB-500 substance was studied in people, for the claimed use, with public results and adequate safety follow-up.
TB-500 is a seven-amino-acid fragment
FDA identifies TB-500 free base as a synthetic N-acetylated fragment corresponding to residues 17 through 23 of thymosin beta-4, with sequence LKKTETQ. Full-length thymosin beta-4 has 43 amino acids. They are not the same substance.
Laboratory signals do not establish injury healing
FDA found a small and difficult-to-transfer nonclinical record. A mouse wound study used non-acetylated LKKTETQ, not N-acetylated TB-500. FDA also reported that TB-500 free base did not significantly improve scratch-wound closure in the reviewed in vitro study.
FDA identified no study that administered TB-500 to people
The 2026 FDA review found no TB-500 clinical studies or human exposure data by any route. Human trials of topical, ophthalmic, injectable, or recombinant full-length thymosin beta-4 answer questions about a different substance and cannot be relabeled as TB-500 evidence.
No FDA-approved TB-500 drug
FDA states that neither TB-500 free base nor TB-500 acetate is part of an FDA-approved drug and staff proposed not adding either to the 503A Bulks List. On July 23, PCAC recommended inclusion after reported 8-6-1 votes on the paired form questions. That advice is nonbinding, not approval, and not final FDA action.
What the TB-500 record shows, and what it cannot prove.
Each row keeps the exact evidence signal beside the conclusion that the current record cannot support.
TB-500 speeds wound or injury healing
A non-acetylated LKKTETQ mouse wound study and limited laboratory work are commonly used to support healing claims. FDA separately reviewed N-acetylated TB-500 free base and TB-500 acetate.
FDA says the mouse finding cannot be directly extrapolated because acetylation changes a peptide's properties. The reviewed in vitro TB-500 free-base experiment did not show significant scratch-wound closure.
TB-500 repairs tendons, ligaments, or muscle
These claims are widespread on seller and wellness pages, but FDA searched the clinical and scientific record for TB-500 administration in humans.
FDA identified no human TB-500 study by any route. Without controlled human evidence, the record cannot establish recovery time, return to sport, tissue repair, functional benefit, or safety.
TB-500 is another name for thymosin beta-4
TB-500 corresponds to an N-acetylated seven-amino-acid fragment. Full-length thymosin beta-4 contains 43 amino acids and appears in separate clinical-trial records.
FDA explicitly states that TB-500 and thymosin beta-4 are not the same substance. Results from a full-length thymosin beta-4 product cannot be transferred to a TB-500 vial or claim.
TB-500 has no known side effects, so it is safe
FDA found no human exposure data and no TB-500 acute, repeat-dose, genotoxicity, reproductive, or carcinogenicity studies. It also found no FAERS reports through March 26, 2025.
No reports and no studies do not establish safety. FDA identifies unresolved immunogenicity, aggregation, peptide-impurity, route, sterility, formulation, and product-quality risks.
One direct TB-500 review and three full-length contrast records.
Only the first row answers the TB-500 human-evidence question. The other rows demonstrate why searching thymosin beta-4 can produce real trials that still do not study TB-500.
Direct TB-500 human evidence search
- Identity
- TB-500 free base or TB-500 acetate
- Design
- FDA literature, clinical, regulatory, and safety review
- Participants
- 0 identified
This is the direct answer for TB-500. FDA identified no clinical studies or other human exposure data by any route, so benefit size, adverse-event rates, pharmacokinetics, dose-response, and long-term safety cannot be estimated.
Topical full-length thymosin beta-4 for pressure ulcers
- Identity
- Full-length thymosin beta-4 topical product
- Design
- Completed Phase 2 study with posted results
- Participants
- 72 actual
This trial can inform questions about its exact topical full-length thymosin beta-4 intervention. It does not establish that a seven-amino-acid TB-500 fragment heals wounds, tendons, ligaments, or muscle.
RGN-259 ophthalmic full-length thymosin beta-4
- Identity
- Full-length thymosin beta-4 ophthalmic product
- Design
- Randomized placebo-controlled study with posted results
- Participants
- 601 actual
A large ophthalmic trial is still a different molecule, formulation, route, tissue, and clinical question. Its existence does not supply human evidence for a seller-labelled TB-500 vial or injectable use.
NL005 recombinant full-length thymosin beta-4
- Identity
- Recombinant full-length human thymosin beta-4
- Design
- Phase IIc, randomized, double-blind, placebo-controlled
- Participants
- 189 estimated
This registry shows continuing research on full-length thymosin beta-4. Estimated enrollment and a planned study do not prove completion or benefit, and the intervention remains distinct from TB-500.
The July 23 recommendation is meaningful, but it is not approval or final action.
FDA staff analysis, advisory committee discussion, and final agency action are three separate stages.
Do not add either TB-500 form
FDA proposes not adding TB-500 free base or TB-500 acetate to the 503A Bulks List after weighing characterization, historical use, effectiveness, safety, and available alternatives.
Read the briefing →Favorable committee recommendation
PCAC recommended inclusion of both reviewed forms after reported 8-6-1 votes. The advice is nonbinding, does not approve TB-500, and does not immediately change the 503A Bulks List.
Open the verified vote record →Final FDA determination
FDA can complete its review after considering advisory input. Until a later agency record is published, the current position must remain described as a proposal.
Track the full process →TB-500 product status and access depend on the destination.
Health Canada and SAHPRA currently name TB-500 in unauthorized or unregistered peptide guidance. Those records are important for their own jurisdictions, but they do not decide approval, prescription, import, compounding, seller, or product status everywhere else.
Nine TB-500 questions, answered from the current record.
This is educational reporting, not medical advice, a prescription, or a use protocol.
What is TB-500?
FDA identifies TB-500 free base as a synthetic N-acetylated seven-amino-acid fragment corresponding to residues 17 through 23 of thymosin beta-4, with sequence LKKTETQ. TB-500 acetate is a separate active pharmaceutical ingredient form. A seller label does not establish exact identity, form, purity, sterility, formulation, or vial contents.
Is TB-500 the same as thymosin beta-4?
No. FDA explicitly states that TB-500 and thymosin beta-4 are not the same substance. TB-500 is a seven-amino-acid N-acetylated fragment, while full-length thymosin beta-4 contains 43 amino acids. A full-length thymosin beta-4 trial therefore cannot be presented as a TB-500 human study or used to authenticate a TB-500 product.
What are the proven benefits of TB-500?
The cited record does not establish a proven human benefit for TB-500. FDA identified no study in which TB-500 free base or TB-500 acetate was administered to people. Laboratory, animal, metabolite, full-length thymosin beta-4, seller, and testimonial records cannot be combined into proof that TB-500 improves healing, recovery, pain, function, or athletic performance.
Does TB-500 heal tendons, ligaments, muscle, or wounds?
There is no cited controlled human TB-500 study establishing faster tendon, ligament, muscle, or wound healing. FDA says a non-acetylated LKKTETQ mouse finding cannot be directly transferred to N-acetylated TB-500, and the reviewed TB-500 free-base scratch-wound experiment did not show a significant closure effect. Full-length thymosin beta-4 trials involve another substance.
What are the side effects of TB-500?
A reliable side-effect profile or event rate cannot be calculated because FDA identified no human exposure data and no adequate TB-500 toxicology program. The absence of FAERS reports through March 26, 2025 does not establish safety. FDA highlights unresolved immunogenicity, aggregation, peptide-related impurity, route, formulation, sterility, and product-quality concerns.
Is TB-500 FDA approved?
No. FDA states that neither TB-500 free base nor TB-500 acetate is a component of an FDA-approved drug. FDA staff proposed not adding either form to the 503A Bulks List, but PCAC recommended inclusion after reported 8-6-1 votes on July 23, 2026. The committee advice is nonbinding, does not immediately change the list, and is not FDA approval, a ban announcement, or a final agency determination.
What is the correct TB-500 dosage?
There is no FDA-approved TB-500 product label or established self-use dosage for the products discussed here. Doses from animal studies, non-acetylated fragments, full-length thymosin beta-4 trials, seller pages, forums, or social posts should not be converted into a personal regimen. This guide does not provide reconstitution, injection, dosing, cycling, or stacking instructions.
Can you buy TB-500 legally in my country?
That depends on the exact product, intended use, destination, import route, medicine authorization, pharmacy and professional rules, and seller status. Health Canada and SAHPRA currently name TB-500 in unauthorized or unregistered peptide guidance, but one country's record cannot decide another country's law. Use the linked 42-country map and official destination records before drawing a conclusion.
Is TB-500 prohibited in sport?
The World Anti-Doping Agency's 2026 Prohibited List names TB-500. Athletes and support personnel should use the current WADA list, their anti-doping organization, and sport-specific medical processes rather than relying on a seller, forum, old list, or the wording research use only. A product's claimed ingredients also do not prove what is actually present.
Related biology is not interchangeable evidence.
A fragment, metabolite, full-length peptide, recombinant protein, formulation, route, animal experiment, and human product can produce different exposure and effects. The exact intervention studied must match the claim being evaluated.
FDA approval, compounding eligibility, anti-doping status, country rules, seller availability, and product authentication are also separate records. None supplies an individual treatment recommendation.