This already IS a huge problem in the medical/health vertical. You should NEVER order supplements, makeup, or medicines/chemicals from Amazon for this reason.
I think there have been a few different noteworthy events where issues have popped up. I'll link to a couple of articles I've found on the topics.
https://themedicinemaker.com/business-regulation/amazons-fda...
https://www.sitejabber.com/resources/counterfeit-cosmetics-t...