Plant Medicine

Plant-derived drugs in the written record

A historical review in the Journal of Anesthesia History states that evidence of human use of opium dates back as far as the sixth millennium BCE, and that Wilhelm Sertürner's chemical isolation of morphine in the early 1800s was the first step in identifying opium's active ingredient.

A pharmacist's history traces aspirin from salicin, a compound in willow bark remedies, to salicylic acid and then to the less toxic acetylsalicylic acid. A historical overview links metformin to Galega officinalis, a traditional European herbal medicine rich in guanidine that was shown in 1918 to lower blood glucose. Metformin itself was later synthesized, was rediscovered in the 1940s during a search for antimalarial agents, and was first reported for diabetes by Jean Sterne in 1957.

Ceremonial plant traditions with dated records

A 2006 review of archaeological and ethnographic evidence from northern Peru reports ritual use of the San Pedro cactus, which contains mescaline, in the Cupisnique (about 1500 BCE), Chavín (about 1000 BCE), Moche (100 to 750 CE) and Lambayeque (750 to 1350 CE) cultures. The authors credit the 17th-century Jesuit Bernabé Cobo with the first detailed description of its ritual use and say the name San Pedro arose in colonial Peru.

James Fernandez's ethnography, first published in 1982, studies Bwiti as a religion of the Fang people of Gabon that drew on several cultural sources under colonial rule. A 2023 historical analysis of reports by explorers and early scientists between 1850 and 1950 examines how Indigenous and Western uses of ayahuasca became entangled in later debate.

Outside demand in the twentieth century

A 2022 history of the psilocybin mushroom trade in the Sierra Mazateca of Oaxaca, Mexico, reports that sales to foreigners began in the 1950s through botanical expeditions and were spurred by collapsing coffee prices. It describes a 1957 magazine article by Gordon Wasson as sparking international interest, and it records tension among Mazatec people over payment for sacred practice.

Three uses of one label

The sources reviewed give no single formal definition of plant medicine, and the label is used in at least three ways. In the broad sense of traditional and complementary medicine, the 2019 World Health Organization global report draws on contributions from 179 Member States. In pharmaceutical writing, researchers classify approved drugs by whether they derive from natural products. In psychedelic research and wellness settings, the phrase is applied to psychoactive plants and fungi, and an Indigenous-led 2022 paper lists plant medicine among its keywords beside traditional healing and spirit medicine.

In the psychedelic field the phrase most often points to ceremonial plants from Indigenous traditions. The sources reviewed document that usage and the concerns around it, but they do not measure how common it is compared with the herbal or pharmaceutical meanings.

Why the distinctions matter

The meanings carry different evidence. A standardized herbal extract, a purified plant-derived drug and a ceremonial preparation used in a communal setting are not interchangeable, and the sources reviewed do not support carrying a finding from one to another. The 2022 Indigenous-led paper names concerns about cultural appropriation, lack of recognition of the sacred position of these medicines, exclusionary practices and patenting of traditional medicines, and proposes eight principles: reverence, respect, responsibility, relevance, regulation, reparation, restoration and reconciliation.

Members of the family

Herbal systems in the sources include Kampo in Japan, described as traditional herbal medicine with a long history; Sowa Rigpa, whose classical texts list 120 mineral ingredients, 28 of which are used in Bhutanese formulations; jamu, a traditional Indonesian medicine compared with Chinese herbal medicine in a 2021 review; ashwagandha, a herb commonly used in Ayurveda; and Chinese formulas such as Yueju and Guipi decoction, assessed in a 2024 umbrella review.

The sources also describe San Pedro, ayahuasca, peyote, iboga with Bwiti, psilocybin mushroom ceremonies, kambo and rapé, a South American nasal snuff. Plant spirit medicine is presented in a practitioner's book as a five-element framework; the sources reviewed do not trace it to a specific Indigenous lineage.

Formula-based herbal systems

Practice varies by system. An overview of Kampo describes standard formulas matched to patterns such as Netsu Sho and Ketsu-Kyo in atopic dermatitis. In Bhutan, 108 multicompound prescription medicines draw on the Sowa Rigpa mineral and herbal repertoire. No session format or training standard common to all herbal systems appears in the sources reviewed.

Ceremonial and ritual settings

In northern Peru, a healing table (mesa) led by a master curandero is held in the early hours of Tuesdays and Fridays and follows a sequence the authors describe as raising, ingesting San Pedro, locating disease, cleansing and flourishing. A Slovenian case report describes a kambo ritual in which dried giant leaf frog secretion was applied to fresh skin burns. A laboratory study describes rapé as a diverse group of South American nasal snuffs with or without tobacco.

Clinical trials differ from ceremonies. A review of 26 registered trials of DMT and ayahuasca found mostly phase I studies with conservative eligibility and extensive cardiovascular and psychiatric exclusions, and ayahuasca is described as a decoction of two plants carrying DMT and beta-carbolines.

Traditional and practitioner purposes

Northern Peruvian curanderos are reported to use San Pedro for psychosomatic conditions and bad luck. Bhutanese Sowa Rigpa formulations are used for more than 135 biomedically defined ailments, and Kampo formulas are used for atopic dermatitis. Unlicensed ibogaine is used by alternative therapists for drug and alcohol addiction. Plant spirit medicine is presented as guidance from plants beyond their physical properties. These are claims made within each setting and not findings.

Uses studied in clinical research

Clinical interest in ayahuasca and DMT has centered on depression, with other psychiatric disorders also named, and ibogaine has been studied in opioid and cocaine dependence. Registered DMT and ayahuasca trials mostly study acute safety rather than disorder-specific outcomes.

Herbal medicine

A 2024 umbrella review of 22 articles on complementary treatments for depression reported that Hypericum mono-preparations showed superior efficacy to placebo and controls, and that the Chinese formulas Yueju and Guipi decoction outperformed conventional antidepressants. This finding concerns depression and the named products and does not transfer to other conditions or to other herbs. The Kampo overview is narrative and reports no certainty rating.

Psilocybin, ayahuasca and ibogaine in trials

An umbrella review of 23 meta-analyses of clinical psychedelic trials reported a large pooled effect for psilocybin in major depression (Hedges g about 1.05), with adverse events generally mild and transient, but noted low methodological quality and limited long-term data. For ayahuasca, a review found few controlled studies with small samples and short follow-up. For ibogaine, a 2026 scoping review identified only three randomized trials, including a 20-person pilot study in cocaine dependence. These clinical findings do not describe ceremonial or retreat use.

Plant-derived drugs

A review of approved drugs from 1981 to 2019 found that natural products and their derivatives account for a substantial share of small-molecule anticancer drugs: 62 of 185 (33.5 percent) were natural products or derived from them, rising to 64.9 percent when compounds based on natural-product pharmacophores were added. This shows the importance of plant chemistry for drug discovery and does not show that crude plant preparations act the same way.

Appropriation and Indigenous governance

The 2022 consensus paper, written by an Indigenous-led group including Wixárika, Maya and Colombian yagé healers, reports concerns from many Indigenous Nations about appropriation and about the absence of Indigenous leadership in Western psychedelic research. A 2026 commentary argues that Indigenous stewardship has often been marginalized through extractive research and commercialization, and calls for free, prior and informed consent and equitable benefit-sharing. A 2022 essay argues that medicalizing ayahuasca without regulation respectful of Indigenous rights could harm Indigenous peoples and potentially plant sustainability. These are argued positions.

Commercialization and plant supply

The Mazatec trade history records that outside demand brought income, benefits captured mainly by intermediaries, and tension over sacred practice. For peyote, a conservation biologist's resource states that demand exceeds supply, that South Texas is the sole commercial source for the Native American Church, and that careless harvesting reduces plant size and survival.

Drug interactions

St John's wort activates the pregnane-X receptor and induces CYP3A4 and P-glycoprotein, with the effect correlating with hyperforin content. In 2000 an interaction with cyclosporine caused acute rejection in two heart transplant patients, and altered levels of drugs including digoxin, tacrolimus, indinavir, warfarin, simvastatin and oral contraceptives have been reported.

Liver injury

A 2025 review describes herb-induced liver injury as a growing concern, with diagnosis complicated by patient non-disclosure of herb use and standard causality tools that fit multi-ingredient products poorly. An Indian series of ashwagandha-related injury reported cholestatic hepatitis; of 8 single-ingredient cases, 3 had acute-on-chronic liver failure and all died, each with preexisting liver disease.

Ibogaine and heart rhythm

Ibogaine blocks hERG potassium channels, which can prolong the QT interval and cause arrhythmia. A review reported 27 fatalities and 8 case reports in people without known heart disease or family history. A 2026 review calls the risk rare but clinically significant, notes variable CYP2D6 metabolism, and says treatment should occur only under medical supervision.

Serotonergic and psychological risks

Harmala alkaloids in ayahuasca inhibit monoamine oxidase, and combining them with SSRIs may cause serotonin syndrome. A critical review of fatality reports found many lacked toxicological detail, yet suggested cardiac and hepatic conditions and serotonergic medication as contraindications. The sources reviewed give no verified count of deaths in retreat settings, and clinical trial exclusions for cardiovascular and psychiatric conditions suggest those groups are not covered by trial safety data.

Kambo, rapé and care boundaries

One kambo case report described profound hyponatremia and seizure. Rapé analysis found high nicotine and several probable carcinogens. These cannot show frequency. Plant practices should not delay or replace necessary medical care, and prescribers should know about any herb or ceremonial plant a person uses.