Plant MedicineTraditional Evidence

San Pedro / Huachuma

Also known as: Huachuma, Wachuma, Echinopsis pachanoi, Saint Peter Cactus

San Pedro (Echinopsis pachanoi), known as Huachuma in indigenous traditions, is a mescaline-containing cactus native to the Andes mountains of Peru, Bolivia, Ecuador, and surrounding regions. With over 4,000 years of ceremonial use, it is one of the oldest entheogens in the Americas, predating psilo...

Applications

7

Clinical Trials

1

Evidence Tier

traditional

Duration

10-14 hours with extended afterglow

Overview

San Pedro (Echinopsis pachanoi), known as Huachuma in indigenous traditions, is a mescaline-containing cactus native to the Andes mountains of Peru, Bolivia, Ecuador, and surrounding regions. With over 4,000 years of ceremonial use, it is one of the oldest entheogens in the Americas, predating psilocybin mushroom use. Archaeological evidence from Peru's Chavín culture (1500 BCE) shows stone carvings of shamans holding the cactus. The Inca used San Pedro in ceremonies at Cusco, Machu Picchu, and the Sacred Valley for spiritual communion with deities, purification, divination, healing, and governance counsel. The primary psychoactive compound, mescaline, increases prefrontal cortex activity for emotional regulation and planning while producing heart-opening, empathogenic effects alongside visual enhancements. Traditional curanderos (healers) in Peru and Ecuador use San Pedro tea in blended indigenous-modern medicine for shamanic healing, enhancing perception, awakening intuition, and diagnosing mind-body-spirit imbalances. The experience, lasting 10-14 hours, typically brings euphoria, compassion, empathy, enhanced environmental awareness, and insights into personal problems. Research supports traditional claims of blood pressure reduction, anti-inflammatory effects, and benefits for depression, anxiety, PTSD, and addiction recovery through serotonin and dopamine activation.

Traditional Use

Used for over 4,000 years by Andean cultures including the Chavín, Inca, and modern Peruvian and Ecuadorian shamanic traditions. Administered by curanderos for healing physical ailments, mental health conditions, spiritual awakening, and treating alcoholism and addiction.

Therapeutic Applications

Depression and anxietyPTSD and traumaAlcoholism and addictionHigh blood pressure and cardiovascular supportChronic pain and inflammationSpiritual and existential distressCreativity and problem-solving enhancement

Clinical Trials

Mescaline for Depression and Anxiety

Limited by Schedule I Status
PhasePreclinical/Observational
InstitutionVarious Research Groups

Dosing Guide

Therapeutic Dose

20-50g dried San Pedro powder (equivalent to 200-400mg mescaline); traditional brews vary widely in concentration

* Dosing should be individualized. Always consult with a qualified healthcare practitioner.

Risks & Contraindications

Potential Risks

  • Nausea and vomiting (especially with traditional preparations)
  • Increased heart rate and blood pressure
  • Potential for challenging psychological experiences
  • Dizziness and physical discomfort
  • Risk of triggering latent psychosis in vulnerable individuals

Contraindications

  • Severe cardiovascular disease
  • Personal or family history of psychotic disorders
  • Pregnancy and breastfeeding
  • Uncontrolled psychiatric conditions
  • Liver or kidney disease

Legal Status

United States

Mescaline is Schedule I. San Pedro cactus legal to grow ornamentally but illegal to prepare for consumption.

International

Legal and traditional in Peru, Ecuador, Bolivia. Mescaline controlled globally; cactus regulation varies.

Key Researchers

Dr. Seeta Durvasula (plant medicine researcher)Wade Davis (ethnobotanist)Dennis McKenna (ethnopharmacologist)

Key Studies

  • 1Traditional ethnobotanical documentation by Peruvian and Ecuadorian researchers
  • 2Preliminary studies on mescaline's effects on prefrontal cortex activity
  • 3Historical archaeological evidence of 4,000+ year use

Quick Facts

CategoryPlant Medicine
Evidence TierTraditional
Duration10-14 hours with extended afterglow
Gabriel Brain Score
77/ 100

Coming Soon on Matter

Access vetted treatment centers, practitioner guidance, and protocol tracking through our Matter platform. Early access launching soon.

Treatment Centers

The Healing Tree Center

Featured

Cusco / Sacred Valley, Peru

RetreatLegal
Practitioner Score89
Visit site →

Arkana Spiritual Center - Sacred Valley

Sacred Valley, Peru

RetreatMedicalLegal
Practitioner Score89
Visit site →

Hummingbird Healing Center - Immersion Program

Iquitos, Peru

RetreatLegal
Practitioner Score88
Visit site →

Hummingbird Healing Center

Iquitos, Peru

RetreatLegal
Practitioner Score87
Visit site →

Gaia Sagrada Ayahuasca Retreat Center

Cuenca, Ecuador

RetreatLegal
Practitioner Score87
Visit site →

Alma Healing Center Ecuador

Mindo, Tumbaco, Pintag, Ecuador

RetreatLegal
Practitioner Score85
Visit site →

Related Substances

Ayahuasca

Ayahuasca is a traditional Amazonian plant brew combining the Banisteriopsis caapi vine (containing MAO inhibitors) with Psychotria viridis leaves (containing DMT). The MAO inhibitors allow the orally inactive DMT to become psychoactive, creating a profound 4-6 hour visionary experience. Indigenous peoples of the Amazon have used ayahuasca for thousands of years in shamanic healing ceremonies for physical ailments, emotional distress, spiritual guidance, and treating addiction. Modern research shows ayahuasca promotes neuroplasticity through sigma-1 receptor activation at mitochondria-associated membranes, reducing inflammation, oxidative stress, and cellular stress responses. Clinical studies demonstrate rapid antidepressant effects, with single doses reducing HAM-D and MADRS scores significantly for up to 21 days. The brew's beta-carboline alkaloids (harmine, harmaline, tetrahydroharmine) contribute additional anthelmintic, antimicrobial, vasorelaxant, and neuroprotective properties. Ayahuasca shows particular promise for substance dependence, acting on mesolimbic dopaminergic and serotonergic pathways to break addiction cues and attenuate withdrawal symptoms. The experience typically involves purging (vomiting, diarrhea), which is considered part of the healing process. Emerging research suggests potential for neurodegenerative conditions like Parkinson's, Alzheimer's, and ALS.

ModerateLearn more →

Ibogaine

Ibogaine is a naturally occurring psychoactive alkaloid derived from the root bark of the Tabernanthe iboga shrub, native to Central West Africa. The Bwiti tradition of Gabon has used iboga in spiritual initiation ceremonies for centuries. Ibogaine is unique among psychedelics for its remarkable ability to interrupt addiction, particularly to opioids, with a single treatment often eliminating acute withdrawal symptoms for weeks and reducing cravings for months. The mechanism involves resetting multiple neurotransmitter systems, including dopamine, serotonin, and opioid receptors, while promoting neuroplasticity and allowing psychological processing of addiction's root causes. A typical ibogaine experience lasts 8-12 hours and involves a waking dream state with intense introspection, life review, and often vivid visions addressing the psychological origins of addiction. Studies show up to 88% reduction in PTSD symptoms post-treatment. However, ibogaine carries significant cardiac risks, including QT interval prolongation and potential fatal arrhythmias, necessitating rigorous medical screening and monitoring. Treatment centers in Mexico (Tijuana, Cancun, Playa del Carmen) and Portugal provide medically supervised protocols with cardiac monitoring, pre-treatment screening, and integration support. Texas approved $50 million in 2025 for clinical trials investigating ibogaine for addiction and brain trauma, signaling growing legitimacy.

EmergingLearn more →

Bufo Alvarius (5-MeO-DMT)

Bufo alvarius (now Incilius alvarius), the Sonoran Desert toad, produces venom containing high concentrations of 5-MeO-DMT, one of the most potent psychedelics known. Despite widespread belief in traditional indigenous use, there is no verified evidence of ceremonial toad venom consumption by indigenous peoples. The Yaqui of the Sonoran Desert considered the toad culturally significant in art and stories but explicitly deny historical ingestion of its venom as psychoactive. Archaeological evidence suggests Mesoamerican awareness of psychoactive toads, but not confirmed ceremonial use. Modern "Bufo ceremonies" emerged around 2015 as neo-shamanic practices, often held at retreats in Tulum, Riviera Maya, Sonora, Oaxaca (Mexico), and Peru's Sacred Valley. The dried venom is vaporized and smoked, producing an extremely intense 15-45 minute experience of ego dissolution, unity consciousness, white light, and often profound healing or trauma release. The toad naturally secretes venom from glands when threatened; this is collected, dried, and stored. Rising global demand for Bufo ceremonies has created serious conservation concerns, with wild toad populations under pressure from over-harvesting. Synthetic 5-MeO-DMT offers an identical experience without harming toads and is increasingly preferred by ethical practitioners. The experience is considered one of the most powerful and potentially transformative in psychedelic medicine, but also carries risks of overwhelming psychological intensity.

EmergingLearn more →