So someone makes a claim for NAC helping with Covid and NAC gets pulled of the market. Seems like a good way to get rid of something you want to get rid off. Start spreading claims on how your competitors product cures Covid and it's good riddens.
It's not about what research shows an ingredient can help with, what your product can help with, or what someone claims a competitors product can help with. It's about irresponsible companies using the word 'Cure' on their products. In the case of NAC, there have been irresponsible companies that have recently gotten warning letters for marketing NAC containing products as a Hangover 'Cure' and a cure for Covid. On a supplement, a company is not legally allowed to market it as a 'Cure' for anything. They could have said 'Helps alleviate the symptoms of a hangover' but cannot say 'hangover cure'.
That's why every supplement labels is supposed to contain the statement 'This product is not intended to diagnose, treat, cure, or prevent any disease'.
Plus, Amazon has their own supplement polices. Just because something isn't allowed on Amazon doesn't mean it isn't legal. This isn't the first time this has happened with Amazon, its just the most high profile. Pretty much anytime the FDA mentions anything, Amazon removes it. Examples are Higenamine, Hordenine, Laxogenin, and a lot more.
In this case, this is the way it was explained to me and seems true:
Company XYZ (actually more than one, but just an example) markets NAC as a Hangover 'Cure' and gets a warning letter. (The letter seemed to be more over the word 'cure' than the ingredient itself).
Company (___ # of idiots) start marketing products as Covid cures or saying it can prevent Covid and that gets FDA attention.
Amazon, seeing the warning letters and the wording about NAC being in formulations for hangover 'cures' pulls Amazon in formulations saying that the FDA considered it a drug. The feeling in the industry is that this stemmed from the warning letter saying they company was making drug claims that NAC was a Hangover 'Cure' bc the word Cure would be considered a drug claim.
^^^ That's why Amazon's original statement was leaving NAC available as a single ingredient but not as a formula. But it now looks like they took those down too.
Bottom line - Companies that make stupid and irresponsible claims cause a lot of damage in this industry and screw things up for everyone.