Trichocereus pachanoi - San Pedro CactusFAMILY: Cactaceae

GENUS: Trichocereus

SPECIES: Pachanoi

COMMON NAMES: Achuma, Aguacolla, Huachuma, San Pedro Cactus

The Trichocereus pachanoi cactus is by far one of the best grafting stocks among cacti, and is often the base stock seen in photographs, so you are probably very familiar with the appearance of this cactus already. Rib number is quite variable, usually ranging from five to eight. Occasionally the sacred four ribbed “Cactus of the Four Winds” is observed, but four ribbed growth is an anomaly, and the addition and subtraction of ribs during growth is quite common. The standard diameter of the species is four inches, and though eight inch specimens have been observed this is probably only in regard to old base material supporting large, multi-branching plants. T. pachanoi is considered largely self-sterile and therefore it is necessary to use different genetic stock for seed production. Much of the stock available in the U.S. market is from a single clone introduced by a man named Curt Backeberg, but T. pachanoi varieties “North Peru” and “Ecuador” have been introduced to the United States market, and it will be interesting to see the differences between these and the Backeberg clone. Presently, these two variations appear to be much more similar to T. peruvianus.

The Trichocereus bridgesii cactus, T. macrogonus, T. pachanoi, and T. peruvianus are all closely related. Some even believe that they are variations of a single species. Flower and fruit similarities suggest to some that T. pachanoi and T. peruvianus are mere variations of a single species, but there is still disagreement on the subject. It has even been suggested that T. pachanoi is a cultivar of either T. bridgesii or T. peruvianus, but it is still the general belief that all are their own independent species, even though intermediary plants appear to exist. It seems likely that such intermediary plants are the result of the importation of T. pachanoi into other areas due to long standing enthnopharmacological use. T. pachanoi is most likely a selectively propagated species and not a strain of T. bridgesii or T. peruvianus.

T. pachanoi may form crested plants with an elongated “fan-like” apex or monstrous specimens that have irregular growth due to fasciation or fusing of tissue. There also appears to be a “minima/prolifera” form of T. pachanoi that has smaller growth and that tillers profusely. These irregular forms might be more properly classified as “short spined” As with most cacti, variegated T.pachanoi seem to be quite rare. Recently a number of interesting T. pachanoi hybrids have been developed, particularly by Sacred Succulents.

The use of T. pachanoi as a replacement sacrament, or in grafting, by members of the Native American Church (NAC) may help preserve the natural populations of L. williamsii (peyote) in the United States, but such propagation techniques are not presently accepted by the NAC.

Trichocereus pachanoi is found abundantly in California, planted primarily for its entheogenic properties, although it is also a popular ornamental cactus. It thrives in the California climate and grows rapidly when watered daily. It is not a desert inhabitant; the San Pedro cactus is indigenous to the warm, humid, rain-rich areas of the Andes where it gets plenty of water. Nevertheless, it can survive months without water. Pieces cut from the cactus can survive for months, even years, and  will often develop lateral shoots, all without food or water.

TRADITIONAL USES: The San Pedro Cactus, or Trichocereus pachanoi, has been in use since the very genesis of the Andean civilization.  It was highly prized as the “materia prima” (raw material) of the shamans of that era. In the central Andes district of Peru, as well as in the surrounding desert regions, the cactus has been an important ritual plant for thousands of years. The oldest archeological proof of its ritual use is found in rock layers dating from the formative period of the Chavin culture, when it seems that the San Pedro cactus was used both as a shamanic medicine and as a sacral inebriant. The cactus has been cultivated on the Peruvian coast since the Early Intermediate Period, 200 B.C.E. to 600 C.E.  Its history dates back to at least 1300 B.C.E., and ceramics and textiles suggest it was well known during the Chavín, Chimú, Nasca, Salinar, and Moche periods. Its present day use by curanderos in healing ceremonies in Peru, Bolivia, and Ecuador has become altered by the integration of Catholic themes with the ancient indigenous beliefs (Davis 1983).

There is very little documentation concerning indigenous use of the San Pedro cactus from the colonial period. The Inquisition did not persecute native use of the cactus (possibly because it was not aware of its existence). Speculation has it that the name San Pedro, the Spanish variation on the name of the Catholic saint, Saint Peter, was in part bestowed on this cactus as an attempt to save it from the Pharmacologic Inquisition. San Pedro is the patron saint of rain, so one can infer a direct link to the origin of the name in association with various sacramental rain cults and pagan rain gods (Ratsch 1998, 505).

There are numerous pre-Columbian artifacts from Nazca and from the Moche-Chimu period that depict columnar cacti which look exactly like Trichocereus pachanoi. An engraved image found on an ancient stele showing the oracle god of Chavin holding this exact cactus in his hand is particularly telling. The cactus in full bloom is found depicted cryptically on two thousand-year-old shamanic textiles of the Chavin culture, albeit in its idealized form, with only four ribs. It is still believed by Peruvian shamans to this day that the four ribbed San Pedro cactus is the most potent, however, no actual modern-day specimens have ever been documented in nature (Cordy-Collins 1982).

Many Mohican stirrup vessels are embellished with column shaped cacti representations, either in three-dimensional relief carvings or with drawings; both are clearly indicative of shamanic associations. An ancient ceramic vessel displays an image of the magical cactus growing out of a deer – an early example of the connection made between a corvine and a plant containing mescaline. A similar connection between deer and the sacred San Pedro cactus is made in the Huichol peyote cult. A Mohican vessel with an image of an erotic scene shows a woman on her back having intercourse in the missionary position with a man who is holding a San Pedro cactus in one hand (Furst 1996).

Shamans would consumed the sacred cactus matter in order to determine whether a patient was ill, and the nature of the illness. The drink was sometimes given to the patient, and less frequently, to others who were present at the ceremony. Prior to partaking of the elixir, laymen would need to prime themselves by “drinking” a decoction of alcohol with tobacco extract through the nasal cavity via a snail shell or other seashell. The snail is known to be a symbol of the San Pedro cactus. This ritual facilitated the layman’s purification and protected her from harmful powers as she embarked on her crossing (Ratsch 1998, 506-507).

Modern day Peruvian shaman still ingest the sacred cactus drink during nocturnal mesa rituals; they also may impart the sacrament onto the others who are present at these ceremonies. The “mesa,” which in Spanish simply means table, is an altar which holds numerous, significant objects such as ceramics, images of saints, shells, sticks, and so forth. The mesa’s structure dates back to pre-Hispanic times and lays out a visionary diagram of where the shaman is going to journey (Ratsch 1998, 507).

Shamans use the San Pedro cactus primarily for psychedelic rituals when they consume it at high doses. However, use of the San Pedro cactus elixir among Peruvian folk healers today is no longer truly shamanic. Preparations of the cactus flesh are often used as aphrodisiacs and tonics by these Peruvian medicine folk, and the drink itself has taken on a more symbolic importance to them than that of pure shamanism. At modern day mesa ceremonies, the dosage used is not large enough to elicit psychoactive effects. However, no matter its potency, the drink is said to inherently heighten visionary and diagnostic perception so that one becomes aware of the mesa objects as they begin to animate.  Most importantly, it allows the soul of the patient to flourish (Ratsch 1998, 507).

TRADITIONAL PREPARATION: T. pachanoi is reputedly made into the hallucinogenic beverage cimora in Huancabamba, Peru, and is used by curanderos for divination, the diagnosis of disease, and to “make oneself owner of another’s identity.” Cimora may include the cactus Neoraimondia macrostibas, Iresine spp., Brugmansia spp., Datura spp., Pedilanthus tithymaloides, and Isotoma longiflora. Though the San Pedro ceremony usually contains other plants, one should not immediately assume that cimora contains T. pachanoi plant matter. The most recognized additives to San Pedro and/or cimora include the tropane alkaloid-containing Brugmansia and Datura species, but these appear to be used only for especially difficult cases requiring deep divination, and are usually taken only by the curandero (Voogelbreinder 2009, 334-335).

An additional aspect of the ceremonies of Huancabamba is the use of “hornamo,” a purgative herb. Hornamo is said to purify the participants, possibly through vomiting. Though most affiliated with Valeriana species, there exists a lengthy list of plants with some form of hornamo used in their vernacular titles. All such herbs are reputedly prepared separate from T. pachanoi, but this may not always be the case (Voogelbreinder 2009, 334-335).

Nicotiana species are commonly included in the San Pedro ceremonies, often as a liquid extract that is nasally ingested prior to the drinking of the San Pedro tea. There has been some suggestion that San Pedro is also used through nasal ingestion, but this route of administration may have its source in the Arts & Entertainment Television broadcast of the program Ancient Mysteries: Ancient Altered States. During this program the ingestion of San Pedro was discussed alongside video of participants nasally ingesting a liquid. It appears the narration mistakenly represented this liquid as San Pedro while failing to discuss the standard oral ingestion of T. pachanoi and the well known nasal use of Nicotiana. If San Pedro is used at all by this method, then most likely it is only a ritualistic act. The volume of mescaline in such a tea would not be concentrated enough to cause an effect unless a truly prohibitive amount was nasally ingested. But of course if one considers the San Pedro ceremony as a purely ritualistic act, as often appears to be the case, then the nasal ingestion of a light concentration of San Pedro tea would not be out of the question (Wade 1983).

Generally, westerners who have participated in the San Pedro ceremonies of Huancabamba, Peru rarely feel the full psychoactive potential of the mescaline present in T. pachanoi. This is often a simple matter of dosage, something the curandero holds sway over as much as the Roman Catholic priest does of the Eucharist. And, like the taking of the Eucharist, the ingestion of San Pedro has largely become a ceremonial act in which the ritual performed plays a larger part in the healing than does direct access to the spiritual otherworld (Wade 1983).

The San Pedro drink is made using fresh cactus stalks or pieces. The chopped cactus is boiled for a few hours in plenty of water. Other plants, such as misha, hornamo, or condorillo, are often added to this mixture. The decoction is then poured off and boiled again for several hours until only about half the original volume remains. Some folk healers use a recipe in which four thin stalks are boiled in approximately five gallons of water for seven hours. Usually one piece of cactus, roughly two to three inches thick and ten inches long is a sufficient dose for each person who will be imbibing the drink. It is sliced into sections and then boiled. Adding lime or lemon juice to the brew helps to dissolve the mescaline, allow it to leech into the liquid more easily (Torres & Torres 1996).

To harvest, the stalks are cut off some four inches or so above the ground. The remaining stumps will sprout shoots again in no time. The stalks should be cut into manageable pieces, about ten to fifteen inches in length, and then the ribs are cut away. The outer rind is sliced from the flesh where the green color of the flesh stops. The fresh skin is laid in the sun to dry for a few hours, then, as it starts to curl up, it is flipped so that the fresh skin is exposed. This process must to be repeated, and can take from two to six days in total (Ratsch 1998, 506).

After thoroughly drying the cactus skins, one grinds them to a fine powder by using a mortar and pestle, a grinding stone, a coffee grinder or a professional device from a pharmacy made for pulverizing the raw material. The important thing to remember is that the finer the powder, the more effective the absorption of the mescaline. Since the cactus powder is unpalatably bitter, many people put the powder into gelatin capsules that hold one gram each. This practice makes it easier to digest and enables the dosage to be as precise as possible (Ratsch 1998, 506).

MEDICINAL USES: In Peruvian folk medicine, shamans use San Pedro brews as a way to diagnose and heal diseases. Cactus flesh preparation are also used to some extent as aphrodisiacs and health tonics (Dobkin de Rios 1968).

TRADITIONAL EFFECTS: T. pachanoi typically contains the following alkaloids: Mescaline (over 25 mg per 100 grams of fresh plant), 3,4-Dimethoxyphenethylamine, 3-Hydroxy-4,5-dimethoxyphenethylamine, 3-Methoxytyramine, 4-Hydroxy-3,5-dimethoxyphenethylamine, Anhalonidine, Hordenine, and Tyramine.  Alkaloid concentration can vary quite widely from plant to plant (Polia & Bianchi 1991).

The effects of T. pachanoi are extremely entheogenic, producing profound psychedelic and empathogenic effects at high enough doses.  Thus this cactus is the ideal tool for a shamanic journey. According to one Peruvian shaman, the effects of T. pachanoi begin with lethargy and a dream-like state, followed by tranquility and finally a clearing of all of the senses and a detachment of the self into a different dimension.  One is set free from their body and allowed to fly through the dimensions of the universe (Hofmann et al. 1992, 168-169).



Cordy-Collins, A. “Psychoactive Painted Peruvian Plants.” Journal of Ethnobiology 2, no. 2 (1982): 144–153.

Davis, E.W. “Sacred Plants of the San Pedro Cult.” Botanical Museum Leaflets 29, no. 4 (1983): 367–386.

Dobkin de Rios, M. “Trichocereus Pachanoi: a Mescaline Cactus Used in Folk Healing in Peru.” Economic Botany 22 (1968): 191–194.

Furst, P.T. “Shamanism, Transformation, and Olmec Art.” In The Olmec World: Ritual and Rulership. Princeton, N.J.: The Art Museum, Princeton University, 1996.

Hofmann, A., Ratsch, C., Schultes, R., Plants of the Gods: Their Sacred, Healing, and Hallucinogenic Powers. Rochester: Healing Arts Press, 1992.

Polia, M., and A. Bianchi. “Ethnological Evidences and Cultural Patterns of the Use of Trichocereus Pachanoi Britt. Et Rose Among Peruvian Curanderos.” Integration 1 (1991): 65–70.

Ratsch, Christian., The Encyclopedia of Psychoactive Plants: Ethnopharmacology and its Applications. Rochester: Park Street Press, 1998.

Torres, D., and M. Torres. “San Pedro in the Pressure Pot.” Yearbook for Ethnomedicine and the Study of Consciousness 1995, no. 4 (1996): 283–284.