Stimulants (also known as psychostimulants and colloquially as "uppers") are a class of psychoactive substances that increase activity of the nervous system to increase alertness, arousal, and motor activity. Stimulants represent one of the three major classes of psychoactive substances: the other two are depressants ("downers") and hallucinogens. Subjective effects include wakefulness, focus enhancement, appetite suppression, thought acceleration, ego inflation, and euphoria.
Stimulants exert their effects through a number of pharmacological mechanisms, the most prominent of which are increasing concentrations of the neurotransmitters dopamine and norepinephrine by either promoting release (e.g. amphetamine, methamphetamine) or by blocking reuptake (e.g. cocaine, methylphenidate). Prominent examples of dopaminergic stimulants include amphetamine, cocaine, methylphenidate, and methamphetamine. Some stimulants also have an additional significant effect on serotonin, such as MDMA, MDA, and methylone. These substances are sometimes separately categorized and referred to as entactogens.
Since their discovery in the early 20th century, stimulants have been adopted throughout the world as prescription medicines for attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity and illicitly as recreational substances.
In addition to intended therapeutic use, many stimulants have significant abuse potential. They can also induce tolerance, and possibly physical dependence, although not by the same mechanism(s) as opioids or depressants. The toxicity of stimulants can vary widely based on the individual properties of each chemical. It is strongly advised to use harm reduction practices when using these substances.
Disclaimer: The effects listed below are cited from the Subjective Effect Index (SEI), which relies on assorted anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be taken with a healthy amount of skepticism. It is worth noting that these effects will not necessarily occur in a consistent or reliable manner, although higher doses (common+) are more likely to induce the full spectrum of reported effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death. These effects are listed and defined in detail within their own dedicated articles below:
Alongside of these a variety of non-essential secondary effects are often present. These generally include but are not limited to:
- Focus enhancement
- Physical euphoria
- Cognitive euphoria
- Appetite suppression
- Memory enhancement
- Analysis enhancement
- Teeth grinding
- Increased music appreciation
- Ego inflation
- Pupil dilation
- Time distortion - This can be described as the experience of time speeding up and passing much quicker than it usually would when sober.
The effects which occur during the offset of a stimulant experience generally feel negative and uncomfortable in comparison to the effects which occurred during its peak. This is often referred to as a "comedown" and occurs because of neurotransmitter depletion. Its effects commonly include:
Experience reports can be found here:
The compounds listed below have been included on the basis of possessing varying degrees of stimulant effects. Some of them have a minimal stimulant effect while others may have a strong one. Many of these substances possess other qualities including entactogenic or nootropic effects.