As mentioned below, they probably don't test for heavy metals on each batch, most companies don't. The reason most don't is that there isn't clear guidance on what specifications to test against. FDA has not provided granular requirements on heavy metals. So why would you spec and test if all you're going to potentially do is get into a bad business situation? Some companies are reporting metals to their consumers on a perform and report basis but that's not common practice. Some are spec'ing against the USP limits, that's best practices, but again not the law.

One critical thing that's lost among most consumers is that dietary supplement companies buy herbal extracts from ingredient companies, those ingredients companies typically get their plants wholesale from independent brokers, and those guys are usually a total mystery to the ds company. Quality problems come from that commodity plant step that weak ds companies are often clueless about.