A Guide to the San Pedro Cactus

The San Pedro Cactus, also called Echinopsis pachanoi or Trichocereus pachanoi, is a fast-growing, thin, columnar cactus species native to altitudes at or over 6,600 to 9,800 feet or 2,000 to 3,000 meters in South America’s Andean mountain region. The San Pedro grows fairly readily in the wild in these areas, including Bolivia, Argentina, Colombia, Chile, Peru, and Ecuador.

A close relative of the Peruvian torch cactus (Echinopsis peruviana or Trichocereus peruvianus), the two are sometimes confused, as they both naturally contain mescaline—one of the best-researched psychedelics. Actually, these two species have become all but interchangeable based on their similarities, at least to laypeople. San Pedro is sometimes called wachuma, but this is the same species.

The San Pedro Cactus was actually among the first substances to be labeled “psychedelic.” For millennia, San Pedro has been a critical piece of the spiritual ceremonies of many indigenous cultures. The San Pedro experience is known for being empathogenic much like MDMA, and particularly in the context of these ceremonies, potentially life-changing. Users report that the San Pedro promotes emotional healing, radical introspection, and feelings of awe and wonder.

San Pedro is consumed traditionally either alone or in a ceremonial brew with other plants called cimora. Strangely, the San Pedro Cactus dots gardens and yards across the US, although its use as a psychedelic is technically illegal. It is also plentiful in the witches’ markets of Peru Bolivia (as Achuma), (as Huachuma and of course San Pedro), and Ecuador (as Gigantón or Aguacolla).

Description and Appearance of San Pedro Cactus

san pedro cactus
“Flowering San Pedro Cactus” by Dankraft is licensed under Creative Commons 2.0. Source.

Echinopsis pachanoi is native to Peru and Ecuador. Stems of the San Pedro are shades of green ranging from light to dark, or sometimes the glaucous grey or bluish green hue seen in cacti. There are typically 6 to 8 ribs, each with a diameter of 2.4 to 5.9 inches or 6 to 15 centimeters.

Areoles of the San Pedros are spaced evenly along the ribs, about 0.8 inches or 2 centimeters apart. White looking, the areoles produce up to seven spines each, which range from yellow to brown and can be up to 0.8 inches or 2 centimeters long. In cultivated specimens of the San Pedro, spines are typically shorter, and sometimes these varieties are mostly spineless.

Typically, Echinopsis pachanoi ranges from 10 to 20 feet or 3 to 6 meters tall with many branches. The tallest specimen of the San Pedro Cactus on record was 40 feet or 12.2 meters tall. Branches usually extend from the base but when they break, new branches also emerge around broken ones. San Pedro cacti can grow as much as 12 inches or 30 centimeters annually depending on their growth environment.

In July, the San Pedro cactus grows pointy buds and large, beautiful white flowers at the end of its stems. These flowers, which measure about 8.7 inches or 22 centimeters in diameter, open at night, smell highly fragrant, and last for approximately two days each. Well established cacti produce large numbers and may open new flowers for weeks.

The unusually massive size of the flower is connected to a large species of Andean hummingbird that pollinates them. These flowers are also pollinated by moths—all at night.

After fertilization, the Echinopsis Pachanoi produces edible, dark green, oblong fruits called Pitahaya. Once they are red-skinned and smell ripe, they are sweet and ready to eat. The fruits are about 1.2 inches or 3 centimeters across and 2.0 to 2.4 inches or 5 to 6 centimeters long.

Pair Echinopsis Pachanoi cacti successfully with Agave truncata, Aloe cameronii, Phormium tenax, and Senecio mandraliscae.

Experience of San Pedro Cactus

Although it occurs naturally, the San Pedro Cactus is a powerful psychedelic. Any ceremony or experience using it can be intense or even overwhelming, potentially. Any given user might feel both beneficial and deleterious effects—at the same time. So although each San Pedro experience is unique, there are some basic things to expect from the process.

What to expect from San Pedro Cactus

Most users begin to feel effects within 15 to 40 minutes of consuming San Pedro Cactus, but peaking can take up to three hours. The coming down process also takes time, about another three hours, and then there is a sort of afterglow period, making the whole experience last around 10 hours or so, typically. Thanks to those lingering effects, it can be tough to sleep after a San Pedro experience as the effects wear off.

If you’ve used other psychedelics, you may be surprised at how different mescaline generally and San Pedro in particular feels. Many users experience heavy, intense effects yet remain feeling in control and relaxed.

Initial effects of San Pedro may include feelings of dizziness or drowsiness, a sense of electricity or tingling in the veins or blood, sweating, and nausea/vomiting. As you would expect from a mescaline-containing psychedelic, the San Pedro Cactus often produces visual effects, including kaleidoscopic patterns, flashes in the periphery, swirls of colored light, and ghostly auras around people.

Other common San Pedro effects include distortions of spatial awareness, mild depersonalization, synesthesia or feeling colors for example, and “out-of-body” experiences. Meanwhile, as you’d expect from mescaline, ordinary objects in the surroundings can appear more beautiful, compelling, and even spiritual.

The high point of all of this is a burst of euphoria, self-realization, connected thought, and empathy. However, particularly among people who don’t follow the 6Ss for psychedelic experiences or who have mental health issues, “bad trips” and dysphoric symptoms are possible.

San Pedro ceremonies

For all kinds of reasons, including ethical concerns and safety risks, the best way to experience San Pedro is in the context of a healer-led ceremony. There are a growing number of well-staffed retreats in South America and Central America, and qualified healers or curanderos are becoming more common outside these regions as well.

Ceremonies frequently last over the course of a night for several days and focus on a healing mesa or altar covered with power objects such as artifacts, religious icons, and images of saints. Typically, these are sorted based on their energy: positive or life-giving, neutral, and negative or death-taking. San Pedro may not be the only plant in use, as curanderos may deploy other plants, cacti, and succulents, including brugmansia, datura, lycopods (clubmosses), and the “Star of Bethlehem,” better known as Isotoma longiflora or Hippobroma longiflora.

Participants in San Pedro ceremonies purify themselves before ingesting the cactus, often by snorting tobacco or taking the baño de florecimiento. The healer diagnoses and treats each person, and this could involve invoking spirits, passing objects over the body, or even laying on of hands in some cases. In certain cases the healer passes a guinea pig over the body, as if to capture the person’s illness, and kills and dissects the animal to determine its source or pathology.

Generally, users attribute cures to the plant rather than the healer or shaman, regardless of what takes place in the ceremony. This is because the healer is considered to be more of a facilitator for activating the cactus using ritual elements such as perfumes, music, and symbols.

Barriers between mind and body dissolve in a traditional ceremony, as shamans typically look for underlying spiritual causes for the illness even when they recognize physical, medical causes of disease—and even integrate pharmaceuticals into their practice. In Western terms, this is a holistic practice, helping patients to view the origins of their illnesses in neutral, nonjudgmental ways—contemporary psychosomatic terms for understanding illness.

San Pedro Cactus Active Ingredients

The San Pedro cactus is rich in alkaloids. Up to 4.7 percent of dry San Pedro Cactus weight is composed of the well-understood compound mescaline (3,4,5-trimethoxyphenethylamine), but the plant is also host to 3-Methoxytyramine, 3,4-dimethoxyphenethylamine, 4-hydroxy-3,5-dimethoxyphenethylamine, 4-hydroxy-3-methoxyphenethylamine, tyramine, anhalinine, anhalonidine, and hordenine.

Mescaline is an entheogen and a psychedelic drug. It also occurs naturally in other species of genus Echinopsis, such as Echinopsis peruviana or the Peruvian Torch, and peyote, the species Lophophora williamsii.

Some evidence indicates that active substances are found in their highest concentrations just beneath the skin in the layer of green photosynthetic tissue.

Pharmacology of San Pedro Cactus

San Pedro Cactus contains mescaline in highly variable amounts. In the greenest, outermost layer of the cacti’s flesh the mescaline is likely to be at its densest. Mescaline is in a different class of psychedelics than the ergolines like LSD and the tryptamines such as DMT or psilocybin. In fact, mescaline is a phenethylamine, similar to MDMA.

The cactus also contains hordenine, an antibiotic, anhalonine, a mild sedative, trichocerine, anhalonidine, tyramine, and several substituted phenethylamines. These likely produce some medicinal benefits, although compared to mescaline, their effects are secondary or negligible.

Receptor binding

Mescaline binds with all of the brain’s serotonin receptors but has more affinity for the 5-HT1A and 5-HT2A receptors. Frequently used when comparing psychedelics as a benchmark hallucinogen, mescaline is structurally similar to LSD. Mescaline also has an affinity for the dopamine receptors, either as a dopamine receptor agonist or as a selective reuptake inhibitor.


The San Pedro Cactus contains highly variable amounts of mescaline, and there is no way to determine by looking just how much any given specimen might contain. This means getting the right dose can be a challenge.

Ideally, users should work with a qualified facilitator of San Pedro ceremonies to ensure they get the right dose. A single 50 gram specimen of dried material from the San Pedro cactus might contain just a threshold dose, as little as 150 milligrams of mescaline, or a potential overdose, as much as 1150mg mescaline.

San Pedro Cactus Benefits and Risks

The San Pedro Cactus offers a number of known benefits and risks to users.

Potential benefits of San Pedro Cactus

A key piece of the shamanic ceremonies of many indigenous cultures in the Americas, the San Pedro Cactus has long been understood to be a powerful change agent and healing tool. Originally, medicine made from the San Pedro Cactus was also used to treat various physical ailments, including general and joint pain, snake bites, skin conditions, and wounds.

Many users feel that San Pedro offers them a sense of spiritual connection, self-awareness, and insight into the universe. Mescaline is also famous for treating psychological disorders such as addiction, anxiety, PTSD, and depression, and fostering gratitude and compassion. Users also claim mescaline helps them access their creativity, solve problems, be more in touch with the environment, and improve their capacity to learn. 

Possible risks from San Pedro Cactus

Research into the potential risks of mescaline—particularly any long-term harm it might cause—has been limited due to its status as an internationally controlled substance. Scientists have yet to identify a lethal dose, likely because it would be difficult to accidentally ingest too high. There have never been any known deaths of mescaline overdose. This is not to say that mescaline use is entirely safe; many cite 1000 mg as the maximum safe dose of the psychedelic, although it’s not clear what the source of that number is.

Research from 2005 showed no detrimental long-term effects among Native American populations from the ceremonial use of peyote. However, especially for those with prior mental health problems, mescaline use in other contexts may not be as safe and may produce “bad trips.” Even so, mescaline appears to present little risk of hallucinogen persisting perception disorder (HPPD) or flashbacks.

Mescaline may not be safe for those with liver problems as it is processed by the liver. Those with colon problems, diabetes, heart conditions, or high blood pressure should also be cautious. Pregnant and breastfeeding women should also avoid peyote as mescaline has been linked to fetal abnormalities, although Huichol women traditionally consume the substance during pregnancy.

It may not be safe to consume San Pedro in combination with natural or synthetic MAOIs, including the antidepressants tranylcypromine (Parnate) and phenelzine (Nardil). Some people take MAOIs such as moclobemide (Aurorix, Amira, Depnil, Clobemix, and Manerix) to prevent nausea or enhance mescaline’s effects, but they may actually increase or induce nausea and could be unsafe.

It’s possible that SSRIs and other non-MAOI antidepressants could reduce the psychoactive effects of the San Pedro Cactus, but combining them is not known to be physically dangerous.

Therapeutic Use of San Pedro Cactus

Much evidence supporting the healing capabilities of San Pedro Cactus is largely anecdotal, and striking stories about its curative powers do exist. This is particularly true with regard to mescaline’s potential to treat mood disorders and other psychotherapeutic potential. Scientists studied the potential of mescaline as a therapeutic substance alone and in combination with LSD in the 1950s and 1960s, along with other psychedelic drugs. The research stopped too soon after mescaline was criminalized, but early results revealed that it might treat depression and addiction successfully.

Recent clinical exploration of mescaline supports these findings from the 1950s and 1960s. For example, research indicates that mescaline may increase activity and blood flow in the brain’s prefrontal cortex, the region tasked with behavior, emotional regulation, planning, and problem-solving. Scientists believe that since low activity in this area is linked to anxiety and depression, mescaline might help treat these disorders.

In fact, among communities where peyote use is common, such as among members of the Native American Church, depression scores are reportedly low. This points to the traditional therapeutic uses for peyote as an antidepressant. Mescaline may also be useful for recalling repressed memories in the context of psychotherapy.

According to researchers at the University of Alabama who studied data from the National Survey on Drug Use and Health, mescaline might help reduce suicidal thoughts. The researchers found lower rates of suicidal thinking among people who have used a psychedelic drug at least once in their life. Research from 2013 also found that lifetime peyote or mescaline use and a lower rate of agoraphobia were significantly linked.

Mescaline also has promise in the treatment of addiction. And although rates of alcoholism are higher among members of Native American tribes, they drop significantly and are lower than average among members of the NAC. One Harvard Medical School researcher who has studied peyote use for years has concluded that the compound in conjunction with the peyote ceremonies themselves reduces rates of drug abuse and alcoholism among Native Americans.

San Pedro Cactus and Personal Growth

As interest in personal and spiritual growth and enlightenment has blossomed among Westerners recently, so has interest in the use of San Pedro and other psychedelics as tools for opening the subconscious and taking a journey inward. The San Pedro Cactus trip elicits healing, personal growth, and deep insights into the universe and the self.

Like other psychedelics, mescaline is well-understood to enhance creativity. One study found that among 27 men who thought about a persistent problem after taking one dose of mescaline, nearly all participants either resolved the issue or generated new ways to approach it. Another study found that mescaline boosted learning capabilities in goldfish who were able to figure out how to avoid shocks.

Microdosing San Pedro Cactus

Microdosing means ingesting or otherwise consuming a psychedelic substance in unnoticeable or sub-perceptual amounts. Although people microdose with LSD and psilocybin more often, mescaline is a good alternative and may be more reliable and consistent than either psilocybin or LSD. Many users also report that microdosing mescaline results in greater personal growth.

In fact, mescaline’s much lengthier history of use extends to microdosing. The use of microdoses of peyote by the Rarámuri and other Native tribes while hunting, for example, enables them to tirelessly stalk deer without resting for days.

Many individuals who microdose mescaline report reduced depression, stress, and anxiety, as well as improved relational skills, increased empathy and focus, more energy, and higher levels of creativity. Some fans of microdosing mescaline also report that the practice enhances their senses, deepens their insights, heightens their spiritual awareness, and produces lucid dreams.

Microdoses of mescaline also have “extraordinarily potent” anti-inflammatory benefits, according to at least one study. This is also one of the ways ancient peoples used mescaline. A 2018 study confirmed that psychedelics as a group, including mescaline, help regulate inflammatory pathways. This in turn suggests they might have therapeutic potential in the treatment of atherosclerosis, asthma, retinal disease, inflammatory bowel disease, and a number of other diseases.

Legality of San Pedro Cactus

It is legal to grow the San Pedro cactus in most places. In the Andean region in countries where it grows naturally such as Ecuador, Peru, and Bolivia, even as a psychedelic the San Pedro is generally legal.

However, where possession of psychedelic compounds such as mescaline is illegal, cultivation of the San Pedro cactus for the purposes of consumption is generally penalized. Currently, people may cultivate the San Pedro cactus for ornamental purposes and gardening, but not for consumption, legally in the United States, Canada, Germany, Sweden, Australia, and New Zealand. (Canada exempts peyote only from its mescaline ban.)

Switzerland, interestingly, specifically prohibits both the Peruvian torch and the San Pedro Cactus.

More specific to the United states, mescaline is an illegal drug listed on Schedule I of the Controlled Substances Act of 1970. However, peyote is the only mescaline-containing cacti specifically scheduled as a controlled substance. This is because intent is at the heart of the law, and consumption as a psychedelic cannot be the reason to grow the San Pedro or other mescaline-containing cacti. Although they are unlikely and rare, prosecutions are possible and could happen.

Some American jurisdictions have laws that recognize the legitimacy of using San Pedro therapeutically. Oakland, California, for example, has decriminalized the use, cultivation, and distribution of all “entheogenic plants” containing tryptamines, indoleamines, and phenethylamines by adults aged 21 years and older. This allows adults to use, grow, buy, and sell these plants for any reason without fear of real criminal fallout.

Cultivation of San Pedro Cactus

Beginners and experienced growers of cacti alike will find cultivating and caring for Echinopsis Pachanoi—or the San Pedro Cactus—rewarding and fun. In fact, because this plant is very versatile and forgiving and needs just a bit of water and occasional nutrients, growing the San Pedro is fairly easy. 

The San Pedro cactus thrives at high altitudes of 6,600 to 9,800 feet, such as the Andes Mountains where it originates. This means that even when grown outside, the San Pedro cactus tolerates cold temperatures well, so long as they don’t fall below 15°F (-9°C). That said, this cactus prefers sunny, temperate climates, ample light, and well-draining, fertile soil if you want to grow it outdoors.

Echinopsis Pachanoi, like all cacti, thrives with warmth and natural light, and mature San Pedro cacti plants usually enjoy full sun. However, San Pedro seedlings can suffer sunburn and are a bit more sensitive. Sunburned Echinopsis Pachanoi displays a yellowing chlorotic reaction.

Due to lower levels of light in winter, Echinopsis Pachanoi plants will etiolate, or thin out its columns. Because strong winds may break the cactus, if the etiolated zone is insufficient to support future growth, this may be problematic.

Although they might not need as much water, the San Pedro Cactus does need some love, care, and attention to grow happy and healthy just like any other plant. Outside, this cactus gets a lot of natural light in its natural habitat, and its soil should be more rich in nutrients than typical cacti soil mix. Inside, keep Echinopsis Pachanoi in a well-lit, sunny spot, ideally on the south-side, and on hot summer days water it more often.

These cacti grow relatively fast, particularly if they are planted in good soil, acclimatized to their growth environment, and watered more frequently during the hot summer season. Growth for established, mature plants can be up to 11 to 12 inches annually.

Echinopsis Pachanoi cacti are fairly susceptible to some pests and fungal infections. The pests are easier to cope with. Common pests that can affect the San Pedro include spider mites, scale, and root mealybugs. Assuming the infestation is not too severe, you can remove all of them easily by scrubbing them off or with neem oil.

Fungal infections such as orange rot and witches broom disease are a problem for San Pedro Cactus, particularly when they get too much water. Take steps to prevent fungal outbreaks by ensuring the cactus has ample heat, a sterile medium, well-drained soil, and proper ventilation. Use a clean knife to remove all impacted pieces of the cactus if you suspect it has a fungal infection. Start a new plant with a few healthy cuttings if the plant has too many lesions.

Like most cacti, which often die from overwatering, San Pedro cacti prefer a dry environment. These beautiful ornamental plants grow well outdoors in USDA Plant Hardiness Zones 8B through 10B. San Pedro cacti thrive in temperate environments, such as the Andean Mountains where they originated.

Outside and subject to the rigors of the sun and heat, especially in summer, San Pedro cacti require more frequent watering. This also means you should bring your watering down in the winter to avoid root rot. When cacti sit in damp soil this can happen, particularly when cold temperatures prevent excess water from evaporating.

The San Pedro Cactus has one big difference from other cacti in terms of care: it requires occasional nutrients. Specific cacti fertilizer includes high levels of potassium and phosphorus, and low amounts of nitrogen.

Propagation of San Pedro Cactus from cuttings

You can propagate Echinopsis pachanoi from cuttings, just like with many other plants. The resulting cactus and the parent plant are genetic clones.

Additionally, as long cactus columns break in storms, they eventually sprout roots as they lay on the ground. Over time, along the length of the fallen column, new cactus columns will grow.

Look for offsets of the San Pedro Cactus around the base of mature plants. There they grow in abundance, and it is simple to propagate new plants from them. Use a clean, sharp knife to safely remove offsets as close as possible to the stem.

Dry out the cutting slightly on a piece of paper. At the narrowest possible place, slice the cutting and allow it to grow a callous. Plant the calloused cutting in a container with well-draining soil and plenty of drainage.

Wait for warmer months to repot Echinopsis Pachanoi, and ensure the soil is dry to prevent root damage. As you work—ideally wearing gloves since these plants have stiff spines—clean any dead or rotten roots and remove as much soil as possible. Watch for diseases and pests and use fungicide to treat any cuts.

Place the plant into the new pot while adding fresh cacti soil mix, spreading the roots as much as possible. Let the plant adjust to its new environment and rest in dry soil for a week; only then start watering it lightly.

Propagation of San Pedro Cactus from seed

As a species, Trichocereus pachanoi like many of its relatives is easy to grow from seed. The most common method is by planting the cactus seeds into takeaway food containers to create a semi-controlled, humid environment. The seed can germinate in the chamber for 6 months to a year, and grow mostly unhurt by environmental contamination.

Ethical Considerations Concerning San Pedro Cactus

Globalization has touched indigenous cultures and the use of the San Pedro Cactus, like everything else. The plant is being used in more unusual and less traditional contexts more often. However, to ensure that destructive, culturally appropriating issues are kept under control, there are some ethical considerations for partaking in a San Pedro ceremony to keep in mind.

Many outsiders are laboring under the “noble savage” stereotype concerning native cultures, which elevates—while misunderstanding—certain practices at the expense of others. Additionally, free market exchange of money for the service of healing adds ethical complexity as this kind of gain may be at odds with some traditional indigenous practices.

The commodification of plant medicine is also a hot topic, with some indigenous organizations and people arguing that people outside a traditional culture should not use them at all.

Some indigenous groups have also spoken out on religious grounds against charging for ceremonies, although others see the practice as a way to uplift their communities. This trend has made some Amazonians welcome the participation of foreigners, willingly participating in the expansion of their ceremonies and the plant medicine industry.

However, as interest in psychedelic tourism in Central and South America grows, so does concern over exploitation of at-risk species such as peyote, unsustainable harvesting practices, the destruction of natural habitat, and the loss of sacred cultural practices. Still, some say that the cultural and pharmacological wisdom of the Amazon basin is well worth sharing and saving globally—so long as that is done with respect.

History and Use of San Pedro Cactus

Humans have used Echinopsis pachanoi in Andean traditional medicine and indigenous cultures for at least two thousand years according to the archaeological record. After Spanish conquest, authorities of the Roman Catholic church tried and failed to suppress its use. This is reflected by the name of the plant, which refers to its heavenly effects.

Long revered by shamans throughout the Andes, San Pedro skins dating back to 2200 BCE have been discovered in Peru. Ceramics, textiles, temple stone carvings, and other more recent artifacts, suggest various pre-Columbian cultures used the cactus, including the Chavín, the Cupisnique, the Lambayeque, and the Moche. Many of these artifacts associate the San Pedro Cactus with symbols such as the boa, deer, hummingbird, jaguar, owl, snail, and stylized steps or spirals thought to represent aspects of the visionary San Pedro experience itself.

Although the Catholic conquistadors suppressed San Pedro’s medicinal and magico-religious uses, the plant was not quite as villainized as peyote. It is possible that the early connection between San Pedro and Christian holidays and symbols was helpful or even strategic. For example, healing ceremonies with San Pedro Cactus were traditionally held on the same day as the Nativity of Saint John the Baptist, June 24th, while the moniker itself refers both to the saint and the heavenly experience.

However, this is not to say that Catholicism took over these ceremonies. In contrast, the same pre-Hispanic and pre-Columbian ideas were simply clothed in foreign context. The San Pedro Cactus has long been associated with water, as have Saints John and Peter.

Wind is also central to San Pedro use, and is often symbolized by swirls, or remolinos. A gust of wind or even a gentle breeze during ceremonies may be seen as the arrival of the plant’s spirit or a portent of good health. When manifested from the air in this way, the spirit of the San Pedro plant is said to assume various forms, including a royal Inca figure, a person with blond hair, Saint Peter himself, or an animal.

For traditional users, out-of-body journeys are an important piece of the use of San Pedro. Some people believe that the geoglyphs of southern Peru known as the Nazca Lines were used as soul maps for these journeys.

Before the San Pedro Cactus was rediscovered by Westerners in 1945, peyote was the only mescaline-containing cacti known to botanists. San Pedro represented a notable alternative source, although it contains less mescaline than peyote.

In 1970 when peyote and mescaline were banned in the United States, San Pedro Cactus mostly escaped the scrutiny of lawmakers. Even as mainstream garden centers continued to stock it freely, those interested in its psychedelic effects went on selling it as a legal, natural alternative.

Current use of San Pedro Cactus

Although it is often technically illegal for consumption, the San Pedro Cactus is widely available in the Western Hemisphere (see Legality of San Pedro Cactus for more information). People who are interested in the San Pedro experience in its native context can choose from a growing number of South American ceremonies and retreats.

Unlike some other natural medicines such as kambo and peyote—perhaps because it grows back so rapidly when cut—San Pedro populations in the wild fortunately appear to be surviving despite surging demand. However, especially in the absence of peyote, overharvesting in certain regions known for “psychedelic tourism” could become unsustainable over time.

Myth: The San Pedro Cactus vs the Peruvian Torch Cactus

In a 1977 book called Peyote and Other Psychoactive Cacti, writer Adam Gottlieb claimed that the Peruvian Torch Cactus has 10 times more mescaline than the San Pedro Cactus. A similar claim was repeated in 1993 by Jonathan Ott in the book Pharmacotheon. Specifically, Ott argued that of any Trichocereus or Echinopsis species, the Peruvian torch has the highest concentration of mescaline.

However, Echinopsis pachanoi or San Pedro Cactus actually appears to be stronger than Peruvian Torch according to analyses of samples of both dried whole plants. Some samples of San Pedro had mescaline concentrations of up to 2.375%, while Peruvian Torch samples had mescaline concentrations ranging from zero up to 0.817%. In the outer, mescaline-rich flesh of both plants, the difference is even greater: 0.24 to 0.25% in most samples of dried Peruvian torch skins with samples of the subspecies Puquiensis containing up to 0.5%, and up to 4.7% in San Pedro.

Of course, mescaline content extensively in both species—so much so that the differences between the two types of cacti are not as significant as differences within each species. This means that certain samples of Peruvian Torch truly might have ten times as much mescaline as some San Pedro samples; this just doesn’t bear out as an average over time.

FAQ About San Pedro Cactus

What is mescaline?

Mescaline (MES-cuh-leen or MES-cuh-lin) is the compound 3,4,5-trimethoxyphenethylamine. However, mescaline is also known as peyote (pay-OH-tee), big chief, blue cap, buttons, cactus buttons, cactus head, chief, media luna, mesc, mescal, mezcakuba, moon, wachuma, san pedro, topi, and other names.

Famous for producing hallucinogenic effects comparable to those produced by sister compounds psilocybin and LSD, mescaline is a psychedelic protoalkaloid that occurs naturally in the wild and is classified as a substituted phenethylamine. Mescaline occurs naturally in various species of cactus, including the San Pedro cactus (Echinopsis pachanoi), the peyote cactus (Lophophora williamsii or Lophophora diffusa), the Peruvian torch (Echinopsis peruvianus), and others.

Before the widespread use of psilocybin and LSD, it was mescaline that entered mainstream Western culture. In modern times, mescaline has promise as a psychotherapeutic and medical treatment for depression, substance abuse, and other conditions.

Compared to other psychedelics, it is rare to find extracts of mescaline in most places. However, when extracted pure mescaline is typically found in crystalline powder form, brownish or white, packed into capsules or loose for consumption. Mescaline can also be brewed into a tea or found in liquid form.

Check out our complete guide to mescaline here.

Can San Pedro Cactus be detected in a drug test?

Mescaline is not typically included in standard drug screens, or even extended drug panels, although it is detectable in urine for up to four days after use. However, unless your employer specifically suspects San Pedro use and is a real stickler, you are probably safe since virtually all labs require a specific test.

Are there risks to using San Pedro Cactus?

There have been no known deaths from mescaline or San Pedro, and least not caused physically by those substances. However, bad choices in terms of setting and planning can lead to risks and danger, as with any psychedelic. San Pedro may be particularly risky for people with a history of heart conditions, mental illness, liver issues, and high blood pressure, as well as women who are pregnant or breastfeeding.

How do I take San Pedro Cactus?

Ideally, users should consume San Pedro on an empty stomach as a dried powder in water, tea, or capsules, as a juice, or as a brew. It is almost unbearably bitter, but some find that chasing it with unsweetened grapefruit juice helps, as does being prepared to experience it without gagging or other resistance.

Is it legal to grow San Pedro at home?

Yes, mostly—see our Legality section for more details. In the US you can grow San Pedro Cactus ornamentally, but not for consumption.

How do I store San Pedro?

Properly stored San Pedro can last for thousands of years, with active ingredients intact. Dry San Pedro cuttings and store them in a dark, cold, dry location.

Can I microdose with San Pedro?

Yes, see above.

Will San Pedro Cactus produce tolerance?

Yes, you can build tolerance to mescaline almost immediately. To get back to baseline it takes about 7 days of abstinence. Mescaline use with other psychedelics such as LSD can also produce a cross-tolerance effect, meaning that after consuming these other psychedelics or mescaline, the next psychedelic, whatever it is, will also have diminished effects for up to 7 days after consumption.

However, mescaline is neither addictive nor habit-forming.

Can I mix San Pedro Cactus with other drugs?

Avoid using San Pedro in tandem with alcohol, blood pressure medications, stimulants like amphetamines and cocaine, immunomodulators, or tramadol.

Some people use San Pedro with cannabis, LSD, or other psychoactive drugs and achieve good experiences. Mescaline is low risk in combination with DMT, psilocybin, ayahuasca, and ketamine.

Final Thoughts on San Pedro Cactus

It is rewarding and fun to grow the San Pedro Cactus or Echinopsis Pachanoi. Thanks to their beautiful flowers, faster growth, and edible fruit they are fairly easy for gardeners, and they even have a psychedelic bonus. Continue the mysterious connection between humans and mescaline by growing your own San Pedro if you’re in the zone!


Species of cacti that contain mescaline, including the San Pedro Cactus, are mostly banned for purposes of consumption, although it is often legal to grow them. Where prohibited by law, we do not support or encourage the use of San Pedro Cactus. However, this guide was created to ensure that anyone who does choose to use San Pedro cactus as a psychedelic or an entheogen can do so safely, given that responsible harm reduction information is critical to ensuring safety, and that illegal drug use occurs.

featured image attribution:
“Flor de Cactus San Pedro” by David Iliff is licensed under Creative Commons 2.0. Source.