TB-500
Tissue & recoveryAlso known as Thymosin Beta-4 fragment
Evidence tier
Multiple human trials
4 human trials · 1 observational · 1 preclinical
- Researched since
- 1979
- Publications
- 1.1k
- Mean purity
- 99.1%
- Vendors listing
- 23
Ascension Peptides shows the highest mean assayed purity for TB-500 at 100.0% across 1 lot record. Purity figures below come from the certificates named in each row.
Score breakdown
The score has two halves: the research base — how long the compound has been studied and how much has been published — and the quality of the evidence the market produces for it, aggregated across every vendor that carries it: assayed purity, lot-to-lot consistency, readable third-party certificates and those vendors’ review record. It measures the evidence base, not the merits or safety of the substance.
Studied since 1979 — 47 years of published research
How long the compound has been studied. Fifteen years or more of published literature earns full marks; a newer compound earns less.
1,063 publications indexed in PubMed
The volume of published literature located. Full marks at fifty or more publications.
Mean assayed purity 99.1% across 20 certificates
Average assayed purity on the certificates published by vendors that carry this compound. Full marks at 99.5%+, nothing at 95% or below.
±1.12 pts purity across lots, mean label deviation 11.9%
How tightly assayed purity and labeled-versus-actual mass hold across different lots. Rewards reproducible manufacturing.
23 of 23 listing vendors publish an accessible certificate policy
Whether the vendors carrying this compound publish per-lot certificates anyone can read without an account.
18 of 20 certificates from a recognised independent lab
Share of certificates issued by a recognised third-party testing lab rather than an unnamed or self-named one.
What is TB-500?
A synthetic peptide fragment related to the naturally occurring protein thymosin beta-4. Supplied as a lyophilised powder.
Studied in published research for tissue repair, recovery and flexibility.
Regulatory status
Labeled by vendors for laboratory research use only. Not an approved medicine in any major jurisdiction.
What the research examines
The areas of published research this compound appears in. These describe what the literature has studied — never a claim of benefit, effect or suitability for any use.
Published research
The published literature is largely preclinical and concerns the parent protein rather than the fragment sold under this name. Vendors frequently cite thymosin beta-4 research when listing TB-500; the two are not identical, and this index records that distinction where a vendor makes the substitution.
- Thymosin beta 4 as an Alzheimer disease intervention target identified using human brain organoids — Stem cell reports (2025)
Peer-reviewed article indexed in PubMed, published in Stem cell reports (2025).
- beta-Thymosins — Annals of the New York Academy of Sciences (2007)
Peer-reviewed article indexed in PubMed, published in Annals of the New York Academy of Sciences (2007).
- Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications — Expert opinion on biological therapy (2012)
Peer-reviewed article indexed in PubMed, published in Expert opinion on biological therapy (2012).
- Identification of glutamine as a potential therapeutic target in dry eye disease — Signal transduction and targeted therapy (2025)
Peer-reviewed article indexed in PubMed, published in Signal transduction and targeted therapy (2025).
- Cardioprotection by Thymosin Beta 4 — Vitamins and hormones (2016)
Peer-reviewed article indexed in PubMed, published in Vitamins and hormones (2016).
- The beta-thymosin enigma — Annals of the New York Academy of Sciences (2007)
Peer-reviewed article indexed in PubMed, published in Annals of the New York Academy of Sciences (2007).
- Thymosin beta 4 interactions — Vitamins and hormones (2003)
Peer-reviewed article indexed in PubMed, published in Vitamins and hormones (2003).
- Thymosin beta 4 — Methods in enzymology (1985)
Peer-reviewed article indexed in PubMed, published in Methods in enzymology (1985).
Indexed studies5 human-evidence of 6
- Published work on thymosin beta-4, the parent protein of TB-500 — Animal
Placeholder seed record. This literature concerns thymosin beta-4, the full parent protein — not the fragment sold as TB-500. Vendors frequently cite this body of work when listing TB-500; the two are not the same molecule, and evidence about one is not evidence about the other.
- Early-phase human work on thymosin beta-4 — Human — controlled trial
Placeholder seed record. A small number of early-phase human studies of the parent protein exist in the listed literature. None were carried through to marketing approval in any jurisdiction, and none concern the TB-500 fragment as sold.
- Malignant thymoma associated with T-cell lymphocytosis. A case report with immunophenotypic and gene rearrangement analysis — Case report, 1993
Patients with malignant thymoma rarely may also have a peripheral T-cell lymphocytosis. "Lymphocyte spillover" from the thymus into the peripheral blood as well as a second, associated neoplasm (ie, T-cell chronic lymphocytic leukemia) are two hypotheses that have been proposed to explain this clinical phenomenon. We describe another patient with a lymphocyte-rich malignant thymoma associated with peripheral T-cell lymphocytosis. At the time of initial diagnosis, the patient'…
- Thymosins: structure, function and therapeutic applications — Human — controlled trial, 1984
Using a partially purified preparation, thymosin fraction 5, we have documented that thymosin can correct many of the immunological deficiencies resulting from the lack of thymosin function in animal models and in humans. Ongoing studies indicate that there is a family of biologically active peptides within fraction 5 that act on T-cell subpopulations to maintain normal immunological reactivity. Several of these peptides have been purified to homogeneity. Two peptides, thymos…
- A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers — Human — controlled trial, 2010
Synthetic thymosin beta 4 (Tbeta4) may have a potential use in promoting myocardial cell survival during acute myocardial infarction. Four cohorts, with 10 healthy subjects each, were given a single intravenous dose of placebo or synthetic Tbeta4. Cohorts received ascending doses of either 42, 140, 420, or 1260 mg. Following safety review, subjects were given the same dose regimen daily for 14 days. Safety evaluations, incidence of Treatment-Emergent Adverse Events, and pharm…
- The effect of thymosin treatment of venous ulcers — Human — controlled trial, 2010
Venous ulcers are responsible for about 70% of the chronic ulcers of the lower limbs. Standard of care includes compression, dressings, debridement of devitalized tissue, and infection control. Thymosin beta 4 (Tbeta4), a synthetic copy of the naturally occurring 43 amino-acid peptide, has been found to have wound healing and anti-inflammatory properties, and is thought to exert its therapeutic effect through promotion of keratinocyte and endothelial cell migration, increased…
Evidence digest
What the research on TB-500 actually shows
Almost all literature cited for TB-500 concerns thymosin beta-4, the full parent protein — not the fragment sold under the TB-500 name. This distinction is the whole story for this compound. A vendor citing thymosin beta-4 research on a TB-500 product page is citing work about a different molecule, and the indexed literature contains no controlled human trial of the fragment as sold.
4 things the literature does not establish →
PepIndex describes what literature exists. We do not interpret it, assess clinical significance, or publish quantities, protocols or instructions for use.
Vendor comparison
| Vendor | Score here | Price / mg | Certificates | Mean purity | Label deviation | Get it |
|---|---|---|---|---|---|---|
| CuroISO/IEC 17025 | 9597% | $3.50 (56%) | 1 | 99.6% | 20.0% | |
| Next Gen PeptidesISO/IEC 17025 | 93.897% | $3.50 (56%) | 3 | 99.8% | 6.0% | |
| Polaris PeptidesISO/IEC 17025 | 93.877% | — | 3 | 99.3% | 21.8% | |
| Amino ClubISO/IEC 17025 | 90.495% | $4.00 (64%) | 1 | 99.3% | 8.8% | |
| PeptidePlugs | 89.790% | $4.00 (64%) | 3 | 99.2% | 21.8% | |
| Hydro Research PeptidesISO/IEC 17025 | 88.289% | $2.80 (45%) | 0 | — | — | |
| NeuroLabs Research | 85.186% | $4.00 (64%) | 0 | — | — | |
| Origin Labs | 81.885% | $3.50 (56%) | 0 | — | — | |
| Koi Peptides | 80.694% | $6.00 (96%) | 0 | — | — | |
| ZC Labs | 79.384% | — | 1 | 99.5% | 10.1% | |
| Good Science Bio | 79.275% | $4.00 (64%) | 0 | — | — | |
| Licensed Peptides | 7789% | — | 1 | 99.8% | 0.5% | |
| Protide Health | 76.794% | $8.50 (136%) | 0 | — | — | |
| American PeptidesISO/IEC 17025 | 74.5100% | $10.00 (160%) | 1 | 99.8% | 21.2% | |
| Northline LabsISO/IEC 17025 | 73.393% | $10.00 (160%) | 1 | 99.5% | 1.5% | |
| Simple Peptide | 7189% | $11.00 (176%) | 1 | 99.5% | 1.0% | |
| Vertex Labs | 70.170% | $9.33 (149%) | 0 | — | — | |
| Improved Peptides | 69.289% | $6.50 (104%) | 1 | 99.1% | 17.6% | |
| Ascension Peptides | 66.186% | $10.00 (160%) | 1 | 100.0% | 2.2% | |
| Mile High Compounds | 64.994% | $6.00 (96%) | 0 | — | — | |
| Eternal Peptides | 63.665% | $7.00 (112%) | 0 | — | — | |
| BioLongevity Labs | 59.274% | $16.50 (250%) | 0 | — | — | |
| Evolve Peptides | 57.267% | $9.00 (144%) | 0 | — | — |
Certificate records
| Vendor | Lot | Tested | Lab | Labeled | Assayed | Discrepancy | Purity | Source |
|---|---|---|---|---|---|---|---|---|
| PeptidePlugs | 101-08-ZB | Freedom Diagnostics Testing | 10 mg | 13.91 mg | 39.1% | 99.3% | Vendor-published | |
| Next Gen Peptides | TB10-08 | ILS Laboratories | 10 mg | 10.58 mg | 5.8% | 99.6% | Vendor-published | |
| ZC Labs | ZCLa2606080083 | Freedom Diagnostics Testing | 10 mg | 11.01 mg | 10.1% | 99.5% | Vendor-published | |
| Curo | TB50SR526 | BTLabs | 5 mg | 6 mg | 20.0% | 99.6% | Vendor-published | |
| Northline Labs | NLL-1698961 | ILS Laboratories | 10 mg | 10.15 mg | 1.5% | 99.5% | Vendor-published | |
| Next Gen Peptides | TB20-5 | ILS Laboratories | 20 mg | 21.43 mg | 7.1% | 99.9% | Vendor-published | |
| Next Gen Peptides | TB10-07 | ILS Laboratories | 10 mg | 10.5 mg | 5.0% | 99.8% | Vendor-published | |
| Improved Peptides | IP-TB500-2026-001 | Principal Chemist | 10 mg | 11.76 mg | 17.6% | 99.1% | Vendor-published | |
| PeptidePlugs | 122-A-S | Freedom Diagnostics Testing | 10 mg | 10.9 mg | 9.0% | 99.1% | Vendor-published | |
| Polaris Peptides | POL-TB10-6 | TrustPointe Analytics LLC | 10 mg | 12.54 mg | 25.4% | 99.1% | Vendor-published | |
| American Peptides | TB10-0318 | Excellence in HPLC-MS Analysis | 10 mg | 12.12 mg | 21.2% | 99.8% | Vendor-published | |
| Simple Peptide | TB15-01092026-J | Freedom Diagnostics | 15 mg | 15.15 mg | 1.0% | 99.5% | Vendor-published | |
| PeptidePlugs | 2603100104 | Freedom Diagnostics Testing | 10 mg | 11.74 mg | 17.4% | 99.2% | Vendor-published | |
| Ascension Peptides | 31-01260229 | MZ Biolabs | 5 mg | 4.89 mg | 2.2% | 100.0% | Vendor-published | |
| Licensed Peptides | TB500T-01 | Vanguard Laboratory | 10 mg | 10.05 mg | 0.5% | 99.8% | Vendor-published | |
| Amino Club | T0101 | ILS Laboratories | 10 mg | 10.88 mg | 8.8% | 99.3% | Vendor-published | |
| Polaris Peptides | SPL-2951 | TrustPointe Analytics LLC | 10 mg | 12.2 mg | 22.0% | 99.4% | Vendor-published | |
| Polaris Peptides | POL-TB10-4 | TrustPointe Analytics LLC | 10 mg | 11.81 mg | 18.1% | 99.4% | Vendor-published | |
| crush-research | 67890 | Quest Diagnostics | 10 mg | 9.8 mg | 2.0% | 97.0% | Vendor-published | |
| blank-peptides | 2023-07 | LabCorp | 10 mg | 9.5 mg | 5.0% | 95.0% | Vendor-published |