Not sure if there's any substance to this type of scare article. Is it a real concern, or the usual doctors proclaiming that all the stuff they prescribe is totally safe and all supplements are incredibly dangerous? I don't know enough to interpret this.
https://www.theguardian.com/society/2022/apr/10/biologists-warn-against-toxic-same-health-supplement
https://www.theguardian.com/society/2022/apr/10/biologists-warn-against-toxic-same-health-supplement