Sold as drugs, supplements, or foods, nootropics include in a number of classes that may have cognitive benefits, including stimulants, nutraceuticals, and racetrams. Scientific research on drugs in these groups range from complete to non-existent.
Let us take a moment to discuss each class individually.
The most studied class of smart drugs stimulants are used mainly to treat patients with cognitive and/or motor function difficulties that stem from disorders such as ADHD and Alzheimer's disease. Medical reviews have found that certain stimulants can recover mental cognition in the general population, but only at low doses or concentrations. You can increase your IQ level by using IQ+ supplements.
Defined as any foodstuff (vitamin, mineral, herb, etc.) that is believed to provide health or medicinal benefits, nutraceuticals are quite popular in old-style Chinese and Hindu medicines. The most common cognitive benefits of this class of drugs are memory enhancement, including both the speed and accuracy of recall.
Often sold as over the counter reason for enhancers, drugs in the racetam family have a wide range of applications. While not the wonder drug you might see in the movies, the most popular member of the family, piracetam, may improve cognitive function without temporary as a sedative or a stimulant.
Although its mechanism of action is not fully understood, investigators do know that the drug increases blood flow and oxygen consumption in certain areas of the brain.
As with any large family of drugs, there are several nootropics that do not fit gracefully into any of the aforementioned categories; either because they don't belong there or they haven't adequately tested to determine where they belong.