MOTS-c is a mitochondrial-derived peptide studied in metabolic research. It is a newer, less commoditised compound, so genuinely independent testing is scarcer and a verifiable certificate matters even more. Whatever you pay, the only way to know a vial actually contains MOTS-c at the stated purity is an independent certificate of analysis you can verify, because purity and identity cannot be judged by eye.
Ignore the marketing. The question is simple: does the seller publish a verifiable Janoshik certificate that names the seller itself as the client? If it does, you can confirm an independent lab tested that batch. If it shows an in-house document, a borrowed certificate, or "COA on request", you cannot. Learn the two-minute check in how to verify a Janoshik COA.
Of the 173 active UK research-peptide sellers we audit, only 20 (12%) publish their own verifiable Janoshik certificate. Any of them is where you can actually verify testing, for MOTS-c or any compound. A few: Lab77Peptides · Velonix Labs · Biohacklondon · Peptifyuk · Biohackpeptides · Peptideprime. See the full independently-tested list, or check a specific shop's certificate with the free COA Checker.
An honest note: a verifiable certificate proves a sample of a batch was tested, not that the specific vial you receive matches it, see what this can and can't tell you. The Peptide Watch sells no MOTS-c and links to no shop; this is research-use-only information, not medical or dosing advice.
Other compounds: BPC-157 · TB-500 · GHK-Cu · Ipamorelin · CJC-1295 · Epithalon · Selank · Semax