Amazon pulled all NAC supplements, a few months ago....
https://articles.mercola.com/sites/articles/archive/2021/06/17/nac-banned-on-amazon.aspx
Was discussed, by a few, on one of the vax threads.
As to NAC, several suppliers (eg Life Extension Foundation and others) have indicated that the NAC ban is illegal, and that they will continue selling.
Just bought some there, a look shows some still for sale.