The best/most powerful stack that we have tried and received feedback on is 300-500mg of Adrafinil, 100-150mg of Phenylpiracetam, and approximately 250mg of Choline. This stack will give you a very good boost of energy, recall, and focus. There are many other stacks that work great for recall, memory, focus, typing, writing, etc, but this is the strongest one we've came across. You can read more about these items at: www.focuspowders.com We are hear to answer any and all questions that you may have