Mama Pacha

Huachuma – San Pedro – Plant Medicine

Huachuma - San Pedro

Huachuma, also known as wachuma or San Pedro is a cactus native to South America. It contains mescaline which is responsible for its psychoactive effects. It usually grows by the sea and there is a big concentration of the cactus on the Peruvian coast. 

There is archaeological proof of huachuma being used by ancient cultures BC found at places like the Chavin temple, Nazca and Moche cultures. After colonization, it was given the name of San/Saint Pedro and ceremonies with huachuma became a blend between Native American culture and Christianity. Yet, Huachuma ceremonies have existed for more than 3000 years.

Chemical Composition

Mescaline is the primary psychoactive, which is an alkaloid that is most prevalent in the green outer skin of the cactus. Mescaline is a phenylethylamine with similar properties to amphetamines such as MDA and MDMA.

Huachuma’s chemical composition is similar to Peyote’s, thus their similar effects. Some of huachuma’s main effects include what the natives call transparent visions, deep connection with nature, and alteration in perception and visions.

Dosage consideration is the same as with ayahuasca and any plant medicine. It varies according to the person, their experience with plant medicine and the shaman’s evaluation.

Huachuma Ceremony

Huachuma is consumed as a juice resulting from the decoction of the cactus. During the ceremony, lemonade is available to help graduate from the trance state. As it is a daytime ceremony, the person usually spends a considerable amount of the journey with eyes open and able to communicate whether it is desirable. 

Huachuma can induce an introspective journey to become in touch with oneself and nature, hence talking might not be appealing. Research has shown that anxiety and stress seem to be less prevalent in people taking huachuma. This might be because it usually induces grounding and peaceful feelings.


Native people consider huachuma a family protector as it improves relationships with others. They cultivate it close to their homes. Huachuma’s effects are similar to peyote’s, it can take up to 2 hours to manifest. The experience is gradual and slower to manifest than with other plants. A huachuma ceremony usually lasts
around 10-12 hours. 

Peyote and huachuma induce profound perception changes. Visions can appear with eyes open and closed. Another common effect is the increase in sensory perceptions such as sound and visions. Huachuma has the potential to induce psychological insight and transcendent spiritual experiences. Research with peyote also has shown that people experience a change in the perception of time and space and one’s self-image. 

According to relevant research, peyote and huachuma have been used since ancient times to treat snake bites, wounds, bruises, rheumatism, dizziness, anxieties, toothache, haemorrhages, headache, phthisis, fever, chest ailments and lung diseases. Additionally, mescaline has also been used to treat mental conditions. Mescaline has a mildly stimulating effect, although some reports suggest an initial state of lethargy after ingesting huachuma.



Mescaline, the psychoactive alkaloid of Huachuma, is a substance controlled by the 1971 Vienna Convention and is listed in Schedule I. It is therefore considered a substance whose use, sale and manufacture are prohibited. However, the Huachuma cactus is not included on the list of scheduled substances and its regulation depends on the legislation of each country. In most countries, the cultivation of the cactus is not prosecuted, whilst preparations, decoctions or extractions made for human consumption may be.  

Risks and Safety

People suffering from high blood pressure or heart disease should refrain from using huachuma as it can cause detriments to their medical condition. Additionally, due to its visionary effect, huachuma is not recommended for people at risk of psychotic episodes. In doing so, they increase the possibility of incurring a psychotic break.

Huachuma effects can take longer to manifest. It is crucial to be patient and avoid taking too many doses believing that the dosage was insufficient when it just needed time to act. 

When taking any plant medicine, the setting and guidance are vitally important. Consuming psychoactive plants responsibly it is to reduce the risk of adverse effects.  


There are considerably fewer studies regarding huachuma than on other plants such as ayahuasca. On the other hand, unlike peyote, huachuma grows rapidly, so it is not an endangered species and self-cultivation is much easier. Still, the use of San Pedro is very limited compared to other plants.