I never worked in supplements, but did work in food production and distribution that are both USDA and FDA regulated, as are supplements (organic supplements are both USDA and FDA regulated) Supplements are definitely USDA and FDA regulated in the US. Of course supplements not manufactured or distributed in the US are not regulated by the FDA. https://www.fda.gov/Food/DietarySupplements/ FDA regulation is not easy, neither is USDA. We also were a Kosher and AIB accredited plant, so we were inspected at least monthly by somebody. FDA typically inspected our plant annually on a schedule and annually on a surprise audit. Audits were rigorous, requiring receiving documents audits, shipping document audits, production reporting audits, inventory, recipes, samples and testing. There were 5 auditors in our plant for a couple weeks and then a follow up with findings, which is why we added the Kosher and AIB accreditation as it made us over-compliant with the government. Reminder, all producers and DISTRIBUTORS of supplements and ingredients in the US are subject to the FDA. The FDA goes so far as to inspect and sample at port of entry into the US. 1 in 5 receipts of imported dried lentils or beans (we made easy to prepare shelf stable entre’s) has a note of sample and how many pounds of samples they took from each bulk bag. Now, back to the caveat.... USDA has no jurisdiction in the DR. Those supplements could have been sourced from anywhere. China is the “Wild Wild East” where anything goes. I once received a recall on Chinese baby formula that was cut with Melamine powder. They cut baby formula with fricken abrasives! Poor babies, that had to hurt! Point is, anything is possible, but unlikely here in the US. I don’t know anything about the rules in DR. Important distinction regarding the FDA between supplements and medications. With supplements you don’t have to prove what the supplement does as long as your legalese on the advertising or package doesn’t make any false claims. It’s easy to skirt.