What are contraindications for the use of piracetam and how should it be used to gain the greatest cognitive enhancement benefit?

Questionable help: Piracetam has theoretical, but no clinical proven efficacy except in protecting the brains of cardiac patients undergoing by-pass surgery. It appears to be safe at dose levels usually administered. It & some derivatives have anecdotal support as adjunctive therapy in some conditions, such as recovery from traumatic head injury. No benefit in normal people.