Hallucinogens: Types, Effects & Dangers

What Are Hallucinogens?

There are many different kinds of hallucinogens and each affects the brain in its own unique way. One relatively broad concept of hallucinogens encompasses two other substance classes: classic hallucinogens and dissociative drugs.¹

Both classic hallucinogens and dissociative drugs can cause hallucinations (i.e. seeing or hearing things that are not there); however, dissociative drugs may also be more likely to result in a person sensing a loss of control or detachment from their own body and their surroundings.¹

Common Types of Hallucinogens

Classic hallucinogen drugs are thought to elicit their effects by disrupting neurochemical signaling involving serotonin, a brain chemical that is central to a person’s mood, sensory perception, and other physiological processes.¹

Some of the more widely-known classic hallucinogens are:¹

• D-lysergic acid diethylamide (LSD): One of the most famous of the mind-altering psychedelic chemicals, LSD was first synthesized in 1938 by the Swiss chemist Albert Hoffman while researching novel stimulant compounds for a pharmaceutical company. LSD has been researched extensively as a possible treatment drug for a variety of disorders.³ However, like all the classic hallucinogens on this list, the DEA classifies LSD as a Schedule I substance, meaning it has no accepted medical uses and a high potential for misuse.⁴ LSD is isolated as a clear or white odorless compound derived from ergot, a fungus that grows on grains.^1,5
• Peyote: The primary ingredient in this small cactus is mescaline. Sometimes called “buttons” or “cactus”, peyote has been used in healing and religious rituals in Central and North America for millennia. Mescaline is sometimes manufactured synthetically.^1,16
• Psilocybin: Psilocybin can be found in many species of mushrooms that are native to South America, Mexico, and the U.S.¹ This hallucinogen, often called “shrooms” or “magic mushrooms” may be dried and either eaten or brewed into tea.⁶
• Dimethyltryptamine (DMT): DMT has a number of natural sources, including the Amazonian plant species Virola. It can also be chemically synthesized. In powder form, it can be smoked, snorted or injected.⁷ Ayahuasca is a plant concoction brewed into a tea and consumed.⁸ Ayahuasca consumption for religious or ceremonial purposes dates back many centuries.⁷
• 25I-NBOMe: Sometimes called “N-bomb,” synthetic hallucinogens such as 25I-NBOMe and 25C were originally developed for medical research but are misused for their hallucinogenic effects that are similar to MDMA and LSD but much stronger.^1,9

Types of Dissociative Drugs

Many dissociative drugs work, in part, by interacting with N-methyl-D-aspartate (NMDA) receptors in the brain to disrupt activity within the glutamate neurotransmitter system.¹⁰ Glutamate is an excitatory neurotransmitter that plays a key role in several brain processes, including those involved with:¹⁰

• Cognition (including memory recall and learning).
• Emotion.
• Pain perception.

The most common and well-known dissociative drugs are:¹

• Phencyclidine (PCP): Historically developed as a general surgical anesthetic, PCP (“angel dust”) produces intense dissociative effects and a euphoric rush.^1,10 Because of its significant side effects (e.g., post-operative delirium and hallucination), it is no longer manufactured for medical use in the United States. PCP is commonly encountered in powder or liquid form but may also be sold in tablets or capsules.¹  It can be smoked, snorted, swallowed, or injected.¹¹ PCP is associated with a number of dangerous acute and long-lasting risks including violent behavior, fatal overdose and addiction.^{11, 12}
• Ketamine: Chemically similar to PCP, ketamine continues to have some limited medical use in both human and veterinary medicine. However, ketamine is also widely misused for its notorious dissociative effects.¹⁶ Dose-dependent effects include a sense of relaxation, immobility, and hallucinations.¹⁷ Someone who is experiencing an intense, immobilizing ketamine high is often said to be in a k-hole.¹⁸ As an illicit club drug, ketamine has reportedly been used to incapacitate others in date rape.^1,18
• Dextromethorphan (DXM): This drug is found in over-the-counter cold and cough preparations.  A person who misuses DXM at high doses may experience hallucinations, delusions, paranoia, and even psychosis, earning DXM the nickname “the poor man’s PCP.”¹⁵
• Salvia: This potent hallucinogen has, like other plant-based hallucinogens, been used for religious rituals in Central America for many years.¹³  Salvia has a very different mechanism of action than many other dissociative drugs. Unlike the others listed in this section, its effects are mediated through activation of the kappa opioid receptor.¹⁰  Salvia is not federally regulated in the US (though some states have passed laws to curtail misuse of the drug). Despite its legality, this drug can be dangerous, causing intense and sometimes frightening hallucinations. Salvia can be smoked, chewed, or converted into vapor and inhaled.¹⁴