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What is Mescaline? Emerging Research, Risks & Side Effects

Written by Will Hunter, BA (Psychology) | Last updated:
Jonathan Ritter
Puya Yazdi
Medically reviewed by
Jonathan Ritter, PharmD, PhD (Pharmacology), Puya Yazdi, MD | Written by Will Hunter, BA (Psychology) | Last updated:

Mescaline is a hallucinogenic compound with a long history of traditional use. It’s found in many different cacti, with the most well-known being peyote. Mescaline produces similar changes in perception as LSD, but not quite in the same way. Read more to learn about the potential dangers of mescaline and discover its possible effects on the body and mind.

Disclaimer: Mescaline is classified as a Schedule I substance. This means that it is an illegal drug with high potential for harm and no known medical uses. We highly advise against the use of mescaline until future studies determine its safety and efficacy in medically-supervised and safe settings. The only aim of this post is to outline research findings.

What is Mescaline?


Mescaline is a hallucinogenic compound most notably found in the peyote cactus (Lophophora williamsii). It is also found in varying degrees in many other members of the cactus family [1].

It is an alkaloid in the phenethylamine class of compounds, which includes other hallucinogens as well as various stimulants, decongestants, and antidepressants. Research suggests that mescaline alters consciousness similarly to the psychedelics psilocybin (from “magic mushrooms”) and LSD [2, 3].

The “Mescaline Cactus”

Mescaline is found in high levels in the peyote cactus and acts as the major active compound. It is concentrated in the small, circular above ground stem tops called “buttons.” Mescaline content in the dried buttons ranges from 2.8% to 3.5% [1, 4, 5].

Peyote also contains other psychoactive alkaloids that may intensify the effects of mescaline [5].

History and Legal Status

Indigenous Use

According to some researchers, mescaline is one of the oldest known hallucinogens used by humans [6].

One estimate suggests that Native Americans in Mexico used peyote as far back as 5,700 years ago. Allegedly, they considered it to be a divine substance with healing properties [7, 8, 1].

Indigenous peoples of South America have reportedly used mescaline-containing cacti such as the San Pedro (Echinopsis pachanoi) and Peruvian torch (Echinopsis peruviana) in folk medicine and religious ceremonies for thousands of years [7, 8, 1].

Scientific Boom

Scientific interest in peyote took off at the end of the 19th century after American newspaper reports of the ritualistic use of peyote by Native American tribes. The search was on to reveal the compound(s) responsible for peyote’s psychedelic effects [1].

This task was accomplished in 1896 by the German chemist Arthur Heffter. After identifying mescaline as one of the active alkaloids in peyote, he tested it on himself and was able to prove that it was responsible for the psychoactive effects of the cactus [1, 9].

Then in 1919, Austrian chemist Ernst Späth found a way to make mescaline in the lab. Shortly thereafter, some experimentally-minded researchers and scientists began dosing themselves and publishing their findings [10].

Psychiatrists in the 1930s and 1940s became particularly interested in mescaline’s ability to mimic certain features of psychosis, a mental condition in which a person loses contact with reality. It can be caused by mental illness such as schizophrenia as well as medications and life-threatening medical conditions [10, 11].

They thought that by artificially recreating the subjective experience of psychosis, they could better understand the condition [12].

In the 1950s, British psychiatrist Humphry Osmond began studying mescaline and LSD’s ability to address mental illnesses, including alcohol addiction. He was somewhat successful, however, his work was cut short by the drug backlash in the 1960s [13].

Osmond later became friends with Aldous Huxley. The famous writer was introduced to mescaline after reading one of Osmond’s papers and requested a sample. Huxley then went on to publish his seminal book “The Doors of Perception,” which gave a detailed account of his experiences with mescaline and spurred public interest in the drug [9].

Subsequent Ban

In 1970, mescaline became illegal with the passing of the Comprehensive Drug Abuse Prevention and Control Act. To this day, it’s classified as a Schedule 1 controlled substance, meaning lawmakers considered it to have [14, 15]:

  • A high potential for misuse and abuse
  • No accepted medical use
  • A lack of accepted safety

Mescaline is also illegal in most other countries. However, mescaline in the form of peyote is legal for religious use by members of the Native American Church (NAC). NAC is a religion that combines Native American beliefs and practices with Christianity and ritualistic peyote use [16, 17].

Clinical research on mescaline was limited after the 1970s ban. Although recent years have seen an increase in research on hallucinogens such as psilocybin, mescaline has not been included in this resurgence due to its relatively low potency and long duration of effects [1].

Potential Effects of Mescaline

Alters Brain Chemistry

The primary mechanism by which mescaline causes hallucinogenic effects is activating 5HT-2A serotonin receptors. All psychedelic drugs, including psilocybin, LSD, and DMT, share this mechanism [3, 18, 19].

Mescaline also activates other serotonin receptors (5HT-1A, 5HT-2B, and 5HT-2C), which may contribute to its effects. These receptors have been implicated in learning and memory, anxiety, mood, and sleep [18, 20, 21].

Besides serotonin receptors, mescaline also activates dopamine receptors in areas of the brain responsible for processing sounds and emotions. This may contribute to the drug’s effect of distorted hearing and enhanced emotions [22].

Limited research suggests that mescaline may increase blood flow and activity in the prefrontal cortex, an area of the brain implicated in planning and pursuing goals, solving problems, self-identity, and regulating emotions and behavior. Some scientists hypothesize that this may affect creativity and focus and possibly underlie the changes in self-identity [23, 24, 25].

By activating neurons in a part of the brain called the locus coeruleus, mescaline is hypothesized to increase the response to stimuli in the environment [26, 27].

According to one unverified theory, this may explain why some users become more sensitive to what’s happening in their environment and why “set and setting” is considered to be crucial during the psychedelic experience [26, 27].

Mescaline might also block the release of acetylcholine, a neurotransmitter that is used to contract muscles. This, in turn, blocks cholinergic activity and may lead to side effects such as muscle weakness and poor balance and coordination [28, 20].

Visuals, Sensory and Perceptual Changes

Mescaline causes a heightened perception of colors, making them more vibrant and intense. Like most psychedelics, it can cause intense visual hallucinations. They have often been described as vibrantly colored patterns including fractals that occur more readily in dim light. Hallucinations of sound, smell, and taste can also occur but are much less common [29, 30, 1, 31, 32].

Research and anecdotes suggest that it also causes a distorted sense of time so that the user becomes unsure of how long they have been under the effects of the drug. Hearing and perception of space may also be distorted [33].

Some reports indicate that mescaline can cause synesthesia, a phenomenon in which senses becomes mixed. For example, certain sounds can cause sensations in parts of the body or certain letters or numbers can be associated with different colors [34].

According to another report, users may also feel as if their body is weightless and that their limbs have changed size and shape [35].


Common to all psychedelics, mescaline can alter the user’s concept of self. Research suggests that higher doses can cause “ego dissolution,” a complete loss of the sense of self and the boundaries between self and the rest of the world [12, 32].

Thoughts and Emotions

Anecdotally, mescaline is said to often produce a dreamlike state of profound wonder. This state of mind may be accompanied by a feeling of euphoria. Interestingly, these kinds of changes have also been scientifically studied. They can be tracked using a specific questionnaire (the Altered States of Consciousness (ASC) questionnaire) [32, 33].

Mescaline vs LSD

This section summarizes research data. Remember that LSD is also still classified as an illegal drug (Schedule I substance).

Some studies imply that LSD is 1,000 to 3,000 times more powerful than mescaline [36, 37].

Research suggests that the effects of both compounds can last up to 12 hours with higher doses, however, mescaline tends to last slightly longer [24, 37, 38].

Because they share the same mechanism of action, mescaline and LSD have very similar effects. They both cause hallucinations, increase suggestibility, intensify emotions and color perception, and may create a subjective sense of deep mysticism or profound wonder [39, 1, 40, 41].

However, users do report slightly different subjective experiences, suggesting they may work differently in certain aspects.

For example, mescaline is more likely to distort the user’s body image, while the loss of control of thoughts is more commonly reported on LSD [40].

LSD may also cause sexual feelings, something rarely reported in mescaline users. The enhancement of colors appears to be more common with mescaline [40].

Another key difference between the two is that mescaline has not been reported to produce “flashbacks,” also known as hallucinogen persisting perception disorder (HPPD). Flashbacks occur when visual and auditory disturbances previously experienced during a trip reappear when not using the drug [42, 43, 44, 45].

Although rare, HPPD is hard to treat and can lead to lifelong disability due to mental health disturbances.

Despite their differences in potency and effects, some researchers think that mescaline and LSD have enough in common that they are hard to tell apart. In fact, in blinded clinical trials, people were unable to distinguish which one they have taken [36, 38].

Mescaline Research Areas

The studies listed below are highly experimental. We summarized them with the aim of sharing the latest research with the general population. The existing studies should guide further investigational efforts. They should not be interpreted as supportive of any health benefit.

Additionally, some of the studies date back to the 60s and used methods that the scientific community today would mainly disqualify. These research efforts are interesting to read about, but they tell us little about mescaline’s effectiveness and safety.

Remember that mescaline is classified as an illegal drug with a high potential for harm.

We highly advise against the use of mescaline until future studies determine its safety and efficacy in medically-supervised and safe settings.

1) Creativity and Problem-Solving

A couple of researchers were interested in whether mescaline can affect creativity and problem-solving skills back in the 60s.

No modern-day studies have looked into this, and it’s impossible to draw any reliable conclusions from old studies. Although studies from the 60s are worth mentioning, they have flaws that render their findings unreliable.

In studies from the 60s, mescaline seemed to produce changes in thinking that were implied in creativity. For example, the authors suggested it [46]:

  • Improved the ability to make associations between unrelated concepts or ideas
  • Reduced inhibitions and self-judgment
  • Enhanced imagination

Researchers wondered if these effects could translate into solving problems that require creative thinking [46].

To do so, they recruited 27 people who worked in jobs that require creative problem-solving ability (e.g. engineers, physicists, and furniture designers). The researchers gave them 200 mg mescaline sulfate and then told them to work on problems related to their field that required a creative solution. The participants also took tests to measure their creativity both before and during the mescaline session [46].

Researchers suggested that mescaline increased creativity as measured by the tests. It was also proposed to improve their ability to solve creative problems by

  • Boosting concentration
  • Increasing the capacity for visual imagery
  • Improving the ability to see problems from different angles
  • Improving the sense of “knowing” when the right solution appears

Purportedly, these improvements were still seen when the participants were assessed two weeks later [46].

The authors thought that mescaline might put people in the “right mindset for creative problem-solving,” but this has never been verified in proper clinical trials.

2) Mental Health

The impact of mescaline on mental health is unknown due to a lack of quality clinical data.

One study looked at the mental health of 61 long-term peyote users in the Native American Church compared to 79 members of the Navajo tribe with no or little history of drug use. According to the study, peyote users reported better psychological well-being and more positive emotions [45].

It’s important to note that mental health was not measured before peyote use started so we don’t know how (or if) it changed over time.

Another study of over 130K people suggested that mescaline use was linked to lower rates of both serious psychological distress and needing psychiatric medication compared to never using the drug [47].

Mescaline use was also associated with a lower rate of agoraphobia, an anxiety disorder in which people fear environments that might cause them to feel trapped or helpless [47].

We can’t say whether mescaline improves mental health due to flaws in the published research.

3) Alcohol Addiction

Some scientists think that serotonin receptor-activators may have the potential to treat alcohol and cocaine dependence. This hypothesis is still highly experimental, though [48].

A couple of clinical trials suggested that LSD has the potential to help with alcoholism, but large-scale data are lacking [49].

Nonetheless, some research teams are interested in further exploring mescaline due to its comparable mechanisms and effects.

There have also been sporadic reports of members of the Native American Church using peyote to prevent alcohol abuse [50].

However, no clinical trials examined mescaline’s effects on alcohol addiction.

4) Learning

The effects of mescaline on learning in humans are unknown. In higher doses, mescaline improved learning in goldfish. However, lower doses actually decreased their ability to learn to avoid a negative stimulus. How this might translate to humans remains a mystery [51].

Mescaline Side Effects, Risks & Drug Interactions

If you have been exposed to mescaline and experience poisoning, urgently contact a poison control center near you (call 1-800-222-1222).

Case Reports

There is one case report of an individual under the influence of mescaline who died of an accidental fall while experiencing hallucinations. It is unknown how much mescaline the person took [52].

Some researchers suggest that taking mescaline in a safe and familiar environment may help reduce the risk of harm, but this has never been verified in human studies [52].

Mescaline caused brain, spinal cord, and liver issues in the newborns of pregnant animals [53, 54].

Psychiatrist Humphry Osmond, who used mescaline in his practice, noted that people who had hepatitis experienced prolonged responses to mescaline [55].

Long-Term Risks

The long-term risks of mescaline are unknown since proper clinical data are lacking.

A study of 61 Native American Church members claimed that peyote use had no negative effects on mental function or psychology. Another study of 130k people did not find an association between mescaline or peyote use and rates of mental health issues. These data are unreliable, though [47, 56].

Physical Side Effects

Mescaline can produce a wide array of effects on the body, including [29, 57, 33, 32]:

  • Dilated pupils
  • Blurred vision
  • Sweating
  • Dry mouth
  • Elevated heart rate
  • High blood pressure
  • Fidgeting and restlessness
  • Muscle weakness
  • Poor coordination and balance
  • Headaches
  • Nausea and vomiting

During the first four hours, body temperature may slightly decline. Thereafter, body temperature increases and may become moderately high. Blood sugar may also rise rapidly for the first hour and then possibly return to normal over the course of the following couple hours [17, 57].

Side effects tend to resolve within 24 hours [29].

Cognitive Side Effects

Mescaline has the potential to cause negative thoughts and emotions, including [57, 1, 32]:

  • Sadness and irritability
  • Fear
  • Anxiety and nervous excitement
  • Depersonalization
  • Difficulty expressing thoughts and focusing
  • Delusions
  • Paranoia

Psychosis and Schizophrenia

The 5-HT2A receptor is thought to play a key role in the development of schizophrenia and psychosis. By activating this receptor, mescaline can produce temporary changes in the brain that mimics those seen in psychotic episodes caused by schizophrenia [58, 59, 60, 23, 24].

No studies have clearly demonstrated that mescaline causes psychosis or schizophrenia.

There is a case report of one otherwise healthy person undergoing a 2-week long psychotic episode after taking peyote in which they experienced visual and auditory hallucinations and could barely sleep. Their symptoms resolved when they got proper sleep [61].

Clinical Trials

There have been a few clinical trials examining the effects of mescaline in chronic schizophrenics. The drug produces similar effects in this population as it does in normal volunteers, including [62, 31, 63]:

  • Visual hallucinations
  • Distorted body image
  • Distorted sense of time
  • Euphoria
  • Paranoia

However, mescaline also caused schizophrenic patients to become highly sexual, verbalizing sexual desires and past experiences. This is rare in normal volunteers [62, 31, 63].

In general, the hallucinogenic experience is much more intense for schizophrenic patients and causes a notable increase in anxiety and disorganized thoughts. Mescaline appears to enhance symptoms specific to the type of schizophrenia the patient has, such as paranoia, fear, and disorganized thinking [62, 31, 63].

Despite the increase in symptoms, the experience has been described as potentially useful in some patients.

In a study of 24 hospitalized schizophrenics, one patient was able to return to her home after significant improvement in her condition. Seven other patients experienced partial improvement, but their symptoms returned within the following weeks [62].

Large, high-quality trials are needed.

Drug Interactions

Drugs that block the 5-HT2A receptor have been suggested to reduce the effects of mescaline. These include [64, 65, 66, 67]:

  • Antidepressants including mirtazapine and trazodone
  • Antipsychotics including haloperidol, clozapine, and risperidone
  • Pizotifen (Sandomigran), used to treat migraines

Members of the Native American Church warn against combining alcohol with peyote [68].


There is no safe dosage of mescaline. Mescaline is an illegal drug that can cause serious side effects. Therefore, we strictly advise against taking it.

This section summarizes research data.

Studies imply that mescaline does not pass through the blood-brain barrier very well. Theoretically, this means higher doses are needed for a psychoactive effect. Likely because of this, mescaline is used less frequently than other psychedelic hallucinogens like psilocybin and LSD [1, 69, 29].

In clinical trials, doses between 200-500 mg mescaline sulfate were used. The scientifically described hallucinogenic dose was 5 mg/kg body weight, or 350 mg for a 70 kg (154 lbs) person [59, 23, 70, 71].

Each peyote button contains around 45 mg of mescaline. The buttons are usually dried and people eat them or soaked them in water to drink [50, 10].

Research suggests that tolerance to mescaline builds after repeated use over the course of days. Taking mescaline may also cause tolerance to LSD, and vice-versa. Cross-tolerance with psilocybin is also likely due to their similar effects on serotonin receptors [72, 70, 73].

According to one study, cross-tolerance may also occur with morphine [74].

Dosage and purity of mescaline sold on the streets illegally are often unknown and may contain LSD or other related (or unrelated) dangerous drugs [47].


Mescaline is the active hallucinogenic compound found in peyote and other cacti. Its history of use allegedly dates back thousands of years.

Compared to the other psychedelics, there are few clinical trials exploring the effects of mescaline. Research suggests that this is likely due to its greater onset of action and duration.

This compound may cause a number of physical and mental side effects. It may also increase schizophrenia symptoms and cause much more intense effects in people with the disorder.

Mescaline remains classified as a Schedule I drug. Until more research emerges or regulations change, mescaline use outside of a research or medical environment is not considered safe.

About the Author

Will Hunter

Will Hunter

BA (Psychology)
Will received his BA in Psychology from the University of California, Los Angeles. 
Will's main passion is learning how to optimize physical and mental performance through diet, supplement, and lifestyle interventions. He focuses on systems thinking to leverage technology and information and help you get the most out of your body and brain.


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