What Are Natural Psychedelics? Classic and Atypical Psychoactive Substances
What natural psychedelics are, how the words psychedelic and entheogen are used, and how classic psychedelics differ from other psychoactive substances such as ibogaine and salvia.
Content last updated . This page has not been medically reviewed.
Natural psychedelics
Psychedelic and dissociative drugs can temporarily change a person's mood, thoughts and perception of reality. The US National Institute on Drug Abuse (NIDA) says many of these drugs come from plants and fungi, some have been used for thousands of years in traditional or religious rituals, and others are made in laboratories. [1] "Natural psychedelics" on this site means substances that occur in a plant or fungus, such as psilocybin in certain mushrooms or mescaline in certain cacti. Natural origin says nothing about safety. A plant or fungus can carry real risks, and products made from them can contain contaminants or other substances. [1]NIDA also notes that people report using these substances for many reasons, including new experiences, spiritual exploration, and hoping to improve their well-being, but that more research is needed to know whether they work for those purposes. [1]
Entheogens
A 2022 scientific primer explains that the word "psychedelic" comes from the Greek for "mind manifesting" and was proposed by Humphry Osmond in 1956. Other words stress other aspects of the experience: "hallucinogens" (perception), "entheogens" (spiritual) and "empathogens" or "entactogens" (social and emotional). [2] So an entheogen is not a separate chemical class. It is a way of describing a substance when it is used in a spiritual or religious setting. Many peoples who use sacred plants describe them in their own words and traditions, and this site tries to use those terms respectfully. See Indigenous traditions, ethics and conservation.Classic psychedelics versus other psychoactive substances
Researchers still debate how to describe and classify these drugs, and they generally group them by how they work in the brain. [1] NIDA uses three groups.| Group | How it works (NIDA) | Examples (NIDA) |
|---|---|---|
| Classic psychedelics | Mainly act on serotonin 5-HT2A receptors | Psilocybin, LSD, DMT, mescaline |
| Dissociative drugs | Block NMDA receptors in the glutamate system | Ketamine, PCP |
| Other drugs | Affect a variety of brain functions | MDMA, ibogaine, salvia |
[1] The US Food and Drug Administration (FDA) uses the term "classic psychedelics" for substances typically understood to be 5-HT2A receptor agonists, such as psilocybin and LSD. [3]
On this site, "atypical" is our own shorthand for natural psychoactive substances that do not fit the classic serotonin pattern, such as ibogaine and salvia (which NIDA puts in its "other" group) and the Amanita muscaria mushroom, whose poisoning involves the compounds ibotenic acid and muscimol. [1][4] It is not an official category.
Where the main compounds come from
| Compound | Natural source | Guide |
|---|---|---|
| Psilocybin | Certain mushrooms found on nearly every continent [5] | Psilocybin mushrooms and truffles |
| Mescaline | Peyote and Echinopsis (San Pedro) cacti [6] | Peyote, San Pedro and mescaline |
| DMT | Leaves of the Psychotria viridis bush, in the ayahuasca brew [7] | Ayahuasca and Amazonian plants |
| Ibogaine | The African rainforest shrub Tabernanthe iboga [8] | Iboga and ibogaine |
| Salvinorin A | The sage Salvia divinorum [9] | Salvia, yopo, morning glory and other plants |
| Ibotenic acid and muscimol | The Amanita muscaria mushroom [10] | Amanita muscaria |
Why the details matter for safety
Effects of psychedelic and dissociative drugs are hard to predict. They depend on the amount and strength, a person's biology, mood, expectations and surroundings, and contaminants or other substances can change the effect. [1] NIDA reports that some of them, including ibogaine, have been associated with a small number of deaths and serious health effects. [1] Mixing with medicines that raise serotonin has been suspected of causing serotonin toxicity in rare cases. [1]Education only
This guide explains terms and categories. It does not tell anyone how to find, prepare or use these substances. For medicines you take, see medication interactions. For how research is labeled on this site, see how we label evidence.Frequently asked questions
What is the difference between a psychedelic and a hallucinogen?
The words overlap. "Psychedelic" is often used for substances acting on serotonin 5-HT2A receptors, while "hallucinogen" is an older, broader word that some people use for all of these drugs. [1]
What does entheogen mean?
It describes substances when they are used in a spiritual context. It stresses the spiritual side of the experience rather than a chemical type. [2]
Is ketamine a psychedelic?
NIDA classes ketamine as a dissociative drug, not a classic psychedelic, because it acts on the glutamate system rather than serotonin receptors. [1]
Are natural psychedelics safer than lab-made ones?
No general rule supports that. NIDA lists both natural and synthetic substances among those with risks and says effects vary widely. [1]
Are these substances approved medicines?
NIDA's page says esketamine, a ketamine derivative, is FDA approved for treatment-resistant depression, while psilocybin formulations had received Breakthrough Therapy designation for study. [1]
References
- National Institute on Drug Abuse, Psychedelic and Dissociative Drugs. Read 2026-10-22.
- Kelmendi B et al. Psychedelics. Curr Biol. 2022;32(2):R63-R67. Read 2026-10-22 (abstract on PubMed).
- US Food and Drug Administration, Psychedelic Drugs: Considerations for Clinical Investigations, Guidance for Industry (July 2026). Read 2026-10-22.
- Meisel EM et al. Two Cases of Severe Amanita Muscaria Poisoning Including a Fatality. Wilderness Environ Med. 2022;33(4):412-416. Read 2026-10-22 (abstract on PubMed).
- National Institute on Drug Abuse, Psilocybin (Magic Mushrooms). Read 2026-10-22.
- Vamvakopoulou IA et al. Mescaline: The forgotten psychedelic. Neuropharmacology. 2023;222:109294. Read 2026-10-22 (abstract on PubMed).
- Dos Santos RG, Hallak JEC. Ayahuasca: pharmacology, safety, and therapeutic effects. CNS Spectr. 2024;30(1):e2. Read 2026-10-22 (abstract on PubMed).
- Litjens RP, Brunt TM. How toxic is ibogaine? Clin Toxicol (Phila). 2016;54(4):297-302. Read 2026-10-22 (abstract on PubMed).
- Grundmann O et al. Salvia divinorum and salvinorin A: an update on pharmacology and analytical methodology. Planta Med. 2007;73(10):1039-46. Read 2026-10-22 (abstract on PubMed).
- Michelot D, Melendez-Howell LM. Amanita muscaria: chemistry, biology, toxicology, and ethnomycology. Mycol Res. 2003;107(Pt 2):131-46. Read 2026-10-22 (abstract on PubMed).