From where I stand, the odds are pretty high — which is exactly why checking out whoever we're buying from matters so much. I looked into a bunch of vendors by digging through reviews, checking other platforms, and seeing whether they put out test reports on a regular basis. Anyone who only tested now and then was out, and so was anyone who simply grabbed a user's report, screenshotted it, and acted like that was enough. A quick read tells us these products carry a research-only label, not for human consumption, so the risks are clear before we even start. Running your own test on that first kit from a new vendor is smart too, then judge from there. My own first attempt came back at 0% peptide, so I dropped that source and swallowed the loss — my health comes first in the end. Filtering is something I always do to cut down contaminant risk, though it never reaches 100%. That's part of what we accept when going grey. Still, with every fresh kit I give my rat .1ml to check for a reaction, then the following day I run the rest, which lets me watch for anything unusual.