Is TB-500 the same as thymosin beta-4?
No — it is a short fragment of it. The human safety data belong to the full protein.
No human trial data
TB-500 Side Effects
No human data for the fragment; the parent protein (thymosin β4) has been through human trials
TB-500 is a synthetic fragment of thymosin β4. Full-length thymosin β4 has been studied in people (eye drops for dry eye and corneal healing; intravenous in cardiac trials) with an acceptable safety profile. The fragment sold as TB-500 has no human trial of its own, so its tolerability is assumed from the parent, not shown.
Research-use information only. Research-grade TB-500 is not an approved medicine; where trial or label figures appear below they belong to the pharmaceutical product studied, not to any research vial. This page does not give dosing or medical advice.
What is reported
Every rate carries its source. Where no source exists, no rate is printed.
| Effect | Rate (sourced) | Detail | Source |
|---|---|---|---|
| Thymosin β4 (parent) in human trials | not quantified | Topical and intravenous Tβ4 were well tolerated in phase 2 studies; adverse events were similar to placebo. | RGN-259 / RGN-352 trial reports |
| Injection-site reactions | not quantified | Expected from any injected peptide; unquantified for TB-500. | General |
What is not known
- •Whether the fragment shares the parent's profile — this is assumed.
- •Any human adverse-effect rate for TB-500 itself.
Mechanism-based cautions
- •Promotes cell migration and angiogenesis — theoretical caution with a tumour history.
- •Some vendors label the fragment as 'thymosin beta-4'; a certificate with molecular weight near 890 Da confirms the fragment.
Regulatory status: Not approved anywhere.
References
- Goldstein AL, Hannappel E, Kleinman HK. Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends in Molecular Medicine, 2005. PMID 16099219.
What is actually in a research vial
Everything above describes TB-500 the molecule. The risk specific to a research vial is different: it may not contain TB-500 at the labelled amount, and it may contain what the synthesis left behind. Identity (mass spectrometry), purity (HPLC), measured net content and an endotoxin result are the four lines on a certificate that bear on adverse effects, and only a certificate you can check at the laboratory tells you any of them. This is what we have verified for TB-500 so far.
Who sells TB-500, and what they document
49 of the 77 vendors on our scoreboard list TB-500 with a price we read on the product page (5 Sept 2026–2 Oct 2026). Of those, 43 name their testing laboratory, 31 publish certificates that resolve on the lab's own site, and 40 publish measured milligrams against the label. The full ranking, with every dated price, is on Best TB-500 Vendors.
| Vendor | Rubric | Lab named | Price read |
|---|---|---|---|
| MyPurePeptidepartner | 10/10 | Janoshik Analytical | $25.00 · 10mg · 30 Sept 2026 |
| Peptide Giantspartner | 10/10 | Janoshik Analytical · Vanguard Laboratory | $48.00 · 10mg · 2 Oct 2026 |
| Purgo Labspartner | 10/10 | SteriGenix · Freedom Diagnostics | $49.99 · 10mg · 2 Oct 2026 |
| Ameano Peptidespartner | 9/10 | Janoshik Analytical | $75.00 · 10mg · 2 Oct 2026 |
| Amino Clubpartner | 9/10 | ILS Labs | $39.99 · 10mg · 2 Oct 2026 |
Top 5 by rubric score; 44 more on the ranking page.
TB-500 certificates we have opened
5 certificates for TB-500 in the COA library: 3 checkable on the laboratory's own site, 5 stating measured mass against the label, 4 carrying a flag.
- Peptide Giants· 5mg · lot PG-5101 · Vanguard Laboratory· 99.3% purity· 98% of label· vendor-hosted onlyOne vial measured
- Evo Labs Research· 10mg · lot 7312026 · Kovera Labs KVR-2026-9F8CE1· 98% of labelverify at Kovera Labs
- Modified Aminos· 10mg · lot MA-TB5I-100 · Ethos Analytics EA Sample ID 20630702-051· 101% of label· vendor-hosted onlyNo lab-side verificationOne vial measured
- MyPurePeptide· 10mg · lot 10292025T5 · Janoshik Analytical #223097 (key 1YF7NYFE4RGI)· 99.007% purity· 115% of labelverify at Janoshik Analytical Over label (>115%)One vial measured
- AIO Peptides· 10mg · lot AIOTB326 · Freedom Diagnostics Search Code AIOP2603060239 (accession 2603060239)· 99.884% purity· 103% of labelverify at Freedom Diagnostics One vial measured