We've been handling this MOTS-c for a while now, and the 16-amino acid sequence is pretty much what you'd expect from a mitochondrial-derived peptide—CAS 1627580-64-6, >99% purity by HPLC, which is solid for metabolic regulation research.
It's not great for anything involving long-term stability at room temp though; you'll need to store it at -20°C and protect from light, or the shelf life drops fast form that 24 months or so.
Most buyers go with the 10mg vials for dose-response work, but we can do 5mg or 20mg depending on your batch—usually 10, but our company can adjust packging if you're ordering 50 units or more.

One thing that might not be obvious: the sequence (Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg) means it's tighter than reagent-grade peptides for metabolic studies, so it's good for nuclear translocation assays.
We typically have stock, but confirm lead time for bulk orders—usually 20 days or so—and our company provide COA with HPLC data for each batch, which is standdard for lab research supplies.
Anyway, it's designed for research use only, not for clinical or cardiovascular applications, and we've been shiping this exact formulation for about three years without complaints.