What's the effect of piracetam on cognitive function? could it be used for a long time safely?

No way to tell : Unfortunately, dietary supplements are regulated as foods (as opposed to drugs). As such, they are not required to undergo the same testing (or prove their claims to be true). Also, since no third party testing of their product is required - the ingredients listed don't even have to match what is in the bottle. Wish I had a better answer ... Good luck!

Yes. Very safe: Piracetam is the prototype of a class of drugs known as "Nootropics." Piracetam was developed in France in the 1970s, and is used primarily to enhance cognitive performance in normal subjects and those with age-related memory impairment. It increases blood flow and glucose uptake in the brain, and increases the production of ATP. There are no known adverse effects in any dose.