TB-500 is a name covering more than one molecule. We check for two of them and tell you which you have — and we are equally clear about the one we do not cover.
$249CAD
Results in about five business days from arrival
Order this testMost material sold as TB-500 is a seven-residue fragment drawn from the actin-binding region of thymosin β4. It comes in two forms: acetylated at the N-terminus, weighing 889.0 daltons, and unacetylated at 847.0. Both are sold under the same three characters.
Authentic thymosin β4 is acetylated at its N-terminus. That acetyl group weighs 42 daltons, and material synthesised without it arrives 42 daltons light.
Forty-two daltons in 889 is under five percent. It is invisible to any method that identifies a peptide by how long it takes to come off a column, and unmistakable to one that weighs it. We scan for both, so the certificate tells you which form you actually have rather than confirming a name.
Some vendors sell the full 43-residue protein, around 4963 daltons, under the same TB-500 label. It is a genuinely different product at a genuinely different price.
It is not on our panel. If your vial contains full-length Tβ4 rather than either fragment, our method will report that neither fragment was detected — which tells you something, but not everything. Write to us first if you believe that is what you have.
Even within the fragment category, suppliers do not always use identical boundaries. That is part of why we report the measured mass rather than simply confirming a name.
10.0%
of TB-500 samples did not contain the stated compound — the highest identity failure rate of any compound measured, one vial in ten. TB-500 also had the lowest median purity at 97.29% and the lowest dual-pass rate at 22.5%.
Mendias C, Awan T, 2026 — 6,441 grey-market samples across 14 compounds and 203 synthesis companies. Posted as a preprint; not peer reviewed. The dataset is self-selected third-party testing, so buyers who already suspected a problem are over-represented. Full findings and caveats.
One unopened vial. Detailed posting instructions arrive with your order confirmation, immediately after you pay.
No. Lyophilised peptides travel safely at room temperature, which is how nearly all samples reach us.
An independent Ontario laboratory. Every certificate we issue names the facility that ran it — we are a testing service, not a laboratory, and we would rather say so than let you find out from the report.
You get the result. We do not soften findings, and we do not charge differently depending on what the analysis shows.
Yes. Every certificate carries an identifier that anyone can check against our records, including the vendor you bought from.
Test your tb-500
$249 CAD · about five business days from arrival · never leaves Canada