How safe and legal is to buy piracetam and picamilon in the USA

They're not scheduled, so they're legal, but not too sell for human consumption. After the FDA cracked down on several companies selling supplements containing picamilon or picamilon for human consumption, many companies removed it from their catalog.

No you can't get in trouble for purchasing them, possessing them, or consuming them, and as long as you are not selling it as a drug or supplement, you can't get in trouble for selling them. Typically companies that sell things like these will sell them as "research chemicals not intended for human consumption".

Oddly, Walmart does advertise Piracetam as a supplement which clearly flies in the face of the FDAs stance but then Sam Walton has more money than God and certainly more than the FDA so they probably won't take him on.

So long as one does not order a massive amount, like say 6 or 5 kilos it should be ok depending on the supplier however you may have to pay taxes or importation fees if dealing with Newstar