OK, real talk. I read all of this and my takeaway is that interpreting COAs correctly requires a chemistry background that most people here (including me) don't have. Am I wrong? I bought a vial of sema from an online vendor. They emailed me a COA. It says 98.1% purity and 5.02mg content. How do I know if the chromatogram is legitimate? I can't tell a good peak shape from a bad one. I can't evaluate whether the method was appropriate. I'm just looking at numbers and trusting the lab. Is there a simpler heuristic for non-chemists? Like — "if it comes from Janoshik with a verification number, it's probably legit"?

You're making a fair point, and I don't want to gatekeep this behind chemistry expertise. Here's a simplified decision tree for non-chemists: Step 1: Is the COA from a recognized third-party lab? - Janoshik, PeptideDetective, Vanta, or a CLIA-certified lab → proceed to Step 2 - Vendor-provided with no third-party verification → treat with skepticism Step 2: Can you verify the COA is genuine? - Use the lab's verification system (Janoshik has one) → if verified, proceed - If no verification system, contact the lab directly with the sample ID - If you can't verify it → it might be fake. Look for community members who tested the same batch. Step 3: Do the key numbers pass? - Purity ≥ 95%? → acceptable - Content within 90-110% of label? → acceptable - Identity confirmed? → acceptable - If all three pass → the product is likely what it claims to be Step 4: Any red flags? - Unidentified impurity peaks above 1%? → concerning - Content below 85% of label? → the vendor is ripping you off - No identity testing performed? → you don't actually know what it is That's it. Four steps, no chemistry degree required. If you want to go deeper, the earlier posts explain the nuances. But for a basic "should I trust this product" assessment, this covers 90% of cases.