Technically speaking, smart drugs are any supplement that enhances cognitive function. Unlike illicit drugs, they are not intended to create a high. Users take these supplements in order to improve their ability to learn, create and recall memories, reason, and concentrate.
Basically, smart drugs increase the natural functioning of brain chemicals. This yields an increase in a variety of cognitive functions. These supplements provide various benefits for cognitive functioning, as well as overall brain health.
As mentioned, smart drugs are anything that improves cognitive function and brain health. Within the nootropic community, these are categorized as compounds that interact with the users brain chemistry to improve specific cognitive functions.
They work directly with the brains natural neurotransmitters, encouraging, controlling, or limiting the production of these chemicals. In doing so, cognitive benefits are experienced.