A psychoactive substance is a chemical substance—other than a nutrient or essential dietary ingredient—that alters brain function to produce temporary changes in sensation, perception, mood, consciousness, cognition, and behavior.
Psychoactive substances are used by humans for a variety of purposes. For example, they can be taken recreationally for their euphoric effects and novelty, as entheogens for ritual or spiritual purposes, or as research tools for augmenting and studying the brain and mind. Many psychoactive substances have established therapeutic utility and are used in routine medical practice (e.g. anaesthetics, analgesics, anxiolytics, antidepressants, etc.).
The psychoactive substance index is designed to catalog and provide relevant, accurate, and unbiased information for any and all psychoactive substances, with emphasis on those that can be used as consciousness expanding tools. The individual articles detail not just the history, chemistry, pharmacology, toxicity, and legality of each substance, but also its unique profile of subjective effects. This is done in accordance with a standardized system of definitions and terminologies found in the subjective effects index.
Please see our summary index to view conveniently condensed versions of each article.