The US is dominant in pharmaceutical and biotech, and FDA is generally excellent as a regulator, despite (IMO) sometimes being too conservative and resistant to any ideas not gestated within the agency. There are weird quirks (like the wide and wacky dosages of melatonin available over the counter, in this example) but most countries have such quirks.
As long as you don’t say anything in the marketing material, you’re good.
The only science in supplements is the marketing.
Unless you have some data to backup this claim, it is tinfoil hat speaking.
Have you never looked into stuff like this? It's all over social media and the claims are relatively easy to verify. I'm asking because I need to know if I'm in a bubble or not.
[1] Cohen PA, Avula B, Wang YH, Katragunta K, Khan I. Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US. JAMA. 2023;329(16):1401–1402. doi:10.1001/jama.2023.2296
https://pmc.ncbi.nlm.nih.gov/articles/PMC10130950/
[2] Erland LAE, Saxena PK. Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content. J Clin Sleep Med. 2017;13(2):275–281. doi:10.5664/jcsm.6462