Stimulant

[Cami]

A substance that raises levels of physiological or nervous activity in the body.

[exinilu]

The word stimulant can refer to any type of drug that increases activity in the central nervous system or sympathetic nervous system, ranging from caffine to methamphetamine.
The most common recreational [stimulants] are commonly called [uppers] and include ADHD medications ([adderall], [ritalin], etc), amphetamines, cocaine, and ecstacy.
The more addictive stimulants generally give the user a sense of euphoria that might include alertness, possible twitching and an overall sense of well-being.
Nicotine, the addictive subtance in tobacco, is a well known stimulant but can also be sedating in higher doses.

[Michiko]

something that makes or causes something else to grow or develop:

[AliceAstes]

a drug that temporarily quickens some vital process