The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications

Strychnos nux-vomica Linnaeus


Poison Nut



A botanical illustration of the flowers and fruits of the poison nut tree. (Engraving from Pereira, De Beginselen der Materia Medica en der Therapie, 1849)



In Germany, the seeds of the poison nut tree (Strychnos nux-vomica) were once known as “crows’ eyes” (krähenaugen). (Woodcut from Tabernaemontanus, Neu Vollkommen Kräuter-Buch, 1731)



The seeds of the poison nut tree (Strychnos nux-vomica) contain strychnine.




Loganiaceae (Logania Family, Strychnos Family); Subfamily Strychneae

Forms and Subspecies





Strychnos colubrina Wight

Strychnos lucida R. Br.

Strychnos spireana Dop

Strychnos vomica St. Lag.

Folk Names


Azaraki, brauntaler, brechnußbaum, cilibucha, fuluz mahi (Persian), gemeines krähenauge, goda kaduru, kajara, kanchurai, krähenauglein, krähenauge(n), krähenaugenbaum, kuchila (Hindi), kuchla, kuchla of India, kuchûlah, noce vomica, noix vomique, nux vomica, nux-vomica tree, poison nut, poison nut tree, Quaker buttons, rvotnyi orech (Russian), strychninbaum, strychnine, strychnine plant, visamusti



Probably the first person to describe the poison nut was Theophrastus, who discussed it under the name strychnós manikós, “strychnos that makes manic.” It was once thought that this name referred to the thorn apple (cf. Datura stramonium), an interpretation that is now considered highly doubtful (Marzell 1922, 171*; Schneider 1974, 3:294*). The “sleeping strychnos” of Dioscorides is now interpreted as Solanum dulcamara, and the “garden strychnos” as Solanum nigrum (cf. Solanum spp.). Many very early Persian sources mention the poison nut as an agent that can induce paralysis (Hooper 1937, 175*). In Europe, the plant first became well known in the fifteenth century.



The tree, which probably originated in the dry forests of Sri Lanka (Macmillan 1991, 416*), is native to India and Burma (Myanmar) but has now spread into all the tropical areas of the Indian Ocean and Southeast Asia (Bremness 1995, 131*). It is most commonly encountered in dry forests.



Propagation occurs through seeds or cuttings. The tree prefers sandy soils and a tropical but dry and hot climate. The seeds are collected primarily between August and November (Macmillan 1991, 417*). The most important areas of cultivation are in Southeast Asia, India, Pakistan, and tropical Africa (Teuscher 1994, 829).



The projecting, shrublike tree can reach a height of up to 25 meters; the trunk can have a circumference of as much as 3 meters. The smooth, shiny, oval leaves are opposite and have five nerves. The greenish white umbels produce yellow fruits with gray, disk-shaped seeds that display a silky sheen through fine small hairs.

The poison nut tree is easily confused with the similar species Strychnos nux-blanda A.W. Hill. The latter, however, has larger flowers and fruits (Teuscher 1994, 829).

Psychoactive Material


—Ripe, dry seeds (brechnuß, krähenauge, strychni semen, nux metella, nux vomica, semen nucis vomicae, semen strychni)

Preparation and Dosage


After the fruits have been collected, the seeds are extracted and dried in the sun. The seeds must be stored in a cool, airtight location that is protected from the light. When seeds are stored properly, the raw constituents should remain stable for a long time. The seeds are used to produce extracts and tinctures for pharmaceutical purposes (Teuscher 1994, 832). To make Ayurvedic medicines, the seeds are boiled in milk or cow urine (this is known as the sodhnatechnique).

The largest therapeutic individual dosage is given as 0.1 g of dried poison nut (with a standardized alkaloid content of 2.4 to 2.6%); the largest total daily dosage is 0.2 g (Teuscher 1994, 836). The dosage of pure strychnine should never exceed 5 mg. In the “drug culture,” strychnine is used as an adulterant to “stretch” cocaine and heroin (Teuscher 1994, 836).

Theophrastus described some rather drastic dosages (which should not be imitated!):


If someone is simply playing a joke and wants to make the biggest fool out of oneself, you take one dram [app. 3.4 g] of it, but 2 drams if he wants to become crazy and experience apparitions; persistent madness can be produced by three drams. Four drams are required to cause death.


In ancient times, the root (1 dram) was drunk in wine for psychoactive purposes. Poison nuts are an ingredient in bhang or majun (see Cannabis indica), Oriental joy pills, and similar aphrodisiacs. In Persia, an aphrodisiac tea was made from poison nuts, hemp (Cannabis indica), and poppy leaves (Papaver somniferum) (Most 1843, 570 f.*).

Ritual Use


It is only as an ingredient in other psychoactive products that poison nuts have acquired any ritual significance (cf. Cannabis indicaVitis viniferaOriental joy pillswine).



In India, poison nuts are used in amulets for magically protecting the house and farm (Jain 1991, 172*).

Medicinal Use


The Ayurvedic medical system regards the seed as a tonic and stimulant (Macmillan 1991, 417*) and especially as an aphrodisiac. In Indian folk medicine, the juice of the root cortex, along with cow’s milk, is applied externally to treat snakebite (Bhandary et al. 1995, 154*). The bark also is used there to treat cholera. In Nepal, the seeds are used for palsy and rabies (Bremness 1995, 131*). In Iran, the seeds were still being used as a tonic in the twentieth century (Hooper 1937, 175*).

In Europe, poison nut seed was once seen as a remedy for the black death (Schneider 1974, 3:295*) and was long regarded as an “agent for strengthening the nerves” (Bremness 1995, 29*). The seeds are used in folk medicine to treat migraines, nervousness, and depression (Teuscher 1994, 835). Homeopathic preparations of poison nuts (Strychnos nux-vomica hom. HAB1, Nux vomica hom. PFX, Angustura spuria hom. HAB34) are used in accordance with the medical description to treat such ailments as ill moods, headaches, and nervous overstimulation (Teuscher 1994, 832). Nux-vomica D6 is said to be a good, dependable treatment for a hangover, even when accompanied by a severe headache (Olaf Rippe, pers. comm.). Combination preparations are also available (see Claviceps purpurea).



The bark, the roots, and especially the seeds contain the indole alkaloids strychnine and brucine, as well as colubrine, pseudostrychnine, vomicine, and strychnicine (Bisset and Choudhury 1974).

The seeds contain an average of 2 to 3% alkaloids but, less frequently, can contain as little as 0.25% or as much as 5.3%. The strychnine content lies between 1.1 and 1.5% but can sometimes reach 2.3%. Also present are 1.1 to 2.1% brucine as well as the secondary alkaloids (comprising a total of no more than 1%) 12-hydroxystrychnine, 15-hydroxystrychnine, α-colubrine, β-colubrine, icajine, 11-methoxyicajine, novacine, vomicine, pseudostrychnine, pseudobrucine, pseudo-α-colu-brine, pseudo-β-colubrine, N-methyl-sec-pseudo-β-colubrine, and isostrychnine (Teuscher 1994, 831).

The flesh and the shell of the fruit contain essentially the same alkaloids as the seeds. In addition, the alkaloid 4-hydroxystrychnine has been demonstrated to be present. The iridoids loganaine and secologanine have been detected as well (Bisset and Choudhury 1974).

The total alkaloid content of the leaves can range from 0.3 to 8.0% (Teuscher 1994, 829). The flowers also contain alkaloids. The bitter fruit pulp, which is sometimes characterized as edible, contains only 0.35% alkaloids.

The stem cortex contains up to 9.9% alkaloids, and the root cortex as much as 18%. The wood of the roots can contain as much as 1.8%, the bark of the branches up to 6.8%, the wood of the branches up to 1.4%, and the wood of the trunk only 0.3% alkaloids. Strychnine is always the primary alkaloid (Teuscher 1994, 829). The root cortex of a sample from Sri Lanka was found to contain a new alkaloid, which was named protostrychnine (Baser et al. 1979).



The effects of poison nuts are almost always the result of their strychnine content. With the exception of 12-hydroxystrychnine, none of the alkaloids exhibits any notable pharmacological activity. Strychnine and 12-hydroxystrychnine are specific antagonists of the neurotransmitter glycine and bind to the same receptors as glycine does. This results in a stimulation of the central nervous system. “The perception of sensory impressions is potentiated, differences in color and brightness are perceived better, the visual field becomes larger, and the sense of taste is improved” (Teuscher 1994, 835). Poison nuts have erotic/psychoactive effects similar to those produced by Pausinystalia yohimba, which is due primarily to the sharpening of sensory perception (vision, sense of smell, sense of taste). In addition, it is possible that men may experience “strong erections” (Roth et al. 1994, 684*).

Overdoses can result in ego dissolution associated with anxiety and severe spasms while remaining fully conscious and ultimately to death through respiratory paralysis. As little as 0.75 to 3 g can be lethal (Teuscher 1994, 836 f.).







“In extracts and in powder form, the crows’ eyes are occasionally used internally; but they always demand great care when they are used. Because of the narcotic properties, they must be stored using the necessary precautions.”






“The strychnos manikos, which some persons call persion [‘round fruit’], others thryon [a plant from the magical gardens of Colchis], anhydron [‘removed from water’], pentadryon [‘five clusters’], enoron, orthogyion. . . . The root, in the amount of 1 dram drunk in wine, has the power to create not unpleasant imaginary images, 2 drams drunk persists for up to three days, 4 drams drunk can even kill. The antidote for this is honey mead, amply drunk and vomited up again.”








In India and Southeast Asia, the powdered seeds of Syzygium cumini (L.) Skeels [syn. Myrtus cumini L., Eugenia cumini (L.) Druce, Eugenia jambolana Lam., Syzygium jambolana (Lam.) DC.] are used as an antidote for overdoses of poison nuts (Macmillan 1991, 417*). In Oceania, Piper methysticum appears to have been used with success as an antidote. In ancient times, mead was considered an antidote. There have been reports of using curare to treat strychnine poisoning (Roth et al. 1994, 684*).

Commercial Forms and Regulations


Poison nuts (which are almost never available through retail sources) require a physician’s prescription and can be obtained only from a pharmacy. The mother tincture as well as homeopathic dilutions up to and including D3 also require a prescription (Teuscher 1994, 838).



See also the entries for Strychnos spp., indole alkaloids, and strychnine.


Baser, Kemal H. C., Norman G. Bisset, and Peter J. Hylands. 1979. Protostrychnine, a new alkaloid from Strychnos nux-vomicaPhytochemistry 18:512–14.


Bisset, N. G., and A. K. Choudhury. 1974. Alkaloids and iridoids from Strychnos nux-vomica fruits. Phytochemistry 13:265–69.


Teuscher, Eberhard. 1994. Strychnos. In Hagers Handbuch der pharmazeutischen Praxis, 5th ed., 6:816–46. Berlin: Springer.


Strychnos spp.


Strychnos Species




Loganiaceae (Logania Family, Strychnos Family); Subfamily Strychneae

The genus Strychnos is represented in both the Old and the New World by some two hundred species (Neuwinger 1994, 517*). Generally speaking, it can be said that the Old World species contain alkaloids of the strychnine type, while New World species contain substances from the curarine group (Macmillan 1991, 432*). Several New World Strychnos species were or still are used to produce curare and similar arrow poisons (Bauer 1965). In addition, several species are used for ethno-medicinal purposes. Strychnos potatorum L. f. is used in Ayurvedic medicine to treat hallucinations. Many New World species contain indole alkaloids, primarily in their bark. Norharman (see harmaline and harmine) was found in an extract of Strychnos barnhartiana leaves (Quetin-Leclercq et al. 1990). The mysterious cabalongahas been interpreted as a species from the genus Strychnos (Strychnos cabalonga hort. Lind.). Many species contain strychnine, which is why they are used as aphrodisiacs and also are potential sources of the raw materials for psychoactive substances.

Strychnos icaja L. (= Strychnos ikaja) [syn. Strychnos dewevrei Gilg, Strychnos dundusanensis De Wildeman, Strychnos kipapa Gilg, Strychnos mildbraedii Gilg, Strychnos pusilliflora S. Moore,


Strychnos venulosa Hutchinson et M.B. Moss]—ikaja, bondes root


Known variously as bondombundumbondo, or icaja (Fang), this plant is a 20- to 100-meter-long vine that can climb as high as 40 meters. Of all the African Strychnos species used to make hunting poison, this is the most important (Neuwinger 1994, 519*). In central Africa, it was used to make arrow poisons (Macmillan 1991, 432*). The red root cortex was boiled to obtain the poison. The plant is considered sacred because it was used in trials by ordeal. An accused person was given the plant to eat. If he survived he was considered innocent. In the Congo, “the macerate of the root is used in palm wine for very painful gastrointestinal complaints and broken bones. In low dosages, it is said to have diuretic and inebriating effects” (Neuwinger 1994, 521*). In Zaire, ashes of the root are used to treat insanity. The plant contains primarily strychnine as well as the related alkaloids icajine, vomicine, and novacine (Neuwinger 1994, 521 ff.*; Ohiri et al. 1983, 177). The missionary Alexander Le Roy (1854–1938) reported the following about this species:


Bwiti, which is the great fetish of the land, has its initiates in the area of Sette Cama [central Africa] and in other places. To be accepted into the secret society, the aspirant must first chew certain roots and drink a decoction of the bark of a tree which is known to botanists as Strychnos icaja. It does not take long for him to fall into a deep sleep and completely lose consciousness. Then a vine [Ipomoea spp.] is tied around his neck. Three days later, when he begins to recover, a magician will ask him to look into a piece of glass that is attached to the belly of Bwiti. He will see certain figures therein, about which he must report. If he says the correct things, he will be accepted; if not, this is taken as a sign that the fetish does not wish to reveal itself to him. (Le Roy 1922, 222)


“The rhinoceros bird is said to have such an immunity to strychnos seeds that they are his favorite food. . . . The poisonous seeds of Strychnos cabalonga are supposedly also eaten by several mammals, such as Dasyprocta agouti.”




This report is illuminating for a number of reasons. First, it provides evidence that the Bwiti cult was found in central Africa as well as West Africa; second, the Bwiti cult, which is now a syncretic, neomessianic movement, is characterized as a pure, typically African fetish cult (cf. Thiel et al. 1986); third, it establishes the use of Strychnos icaja as a psychoactive substance; and fourth, it supports the theory that Strychnos icaja is used as an iboga substitute (cf. Tabernanthe iboga). Of further interest is the description of how the aspirant is bound with a vine, another plant that can be included in the circle of psychoactive plants.

Strychnos ignatii Bergius [syn. Ignatia amara L. f., Ignatia philippinensis Blume, Ignatiana phillippinica Lour., Strychnos balansae A.W. Hill, Strychnos beccarii Gilg, Strychnos blay-hitamDragendorff, Strychnos cuspidataA.W. Hill, Strychnos hainanensis Merr. et Chun., Strychnos krabiensis A.W. Hill, Strychnos lanceolaris Miq., Strychnos ovalifolia Wall. ex G. Don, Strychnos philippensis Blanco, Strychnos pseudo-tieuté A.W. Hill, Strychnos tieuté Lesch]—Ignatius bean


This creeping climber, which is also known as bitter fever nut and Saint-Ignatius’s-bean, originated on the Sunda Islands and in the Philippines but is now found throughout Southeast Asia. In Malaysia, the Ignatius bean is regarded as upas radja, “royal poison,” and was used both as an arrow poison and to commit murder (Lewin 1920, 556*). Reports of the plant’s psychoactive properties had already appeared by the early modern period: “The Ignatius bean has a very energetic action upon the nervous system . . . acting in the very same manner as the poison nut [Strchynos nux-vomica]” (Meissner in Schneider 1974, 3:297*).

Today, the Ignatius bean is used by the pharmaceutical industry as a source of strychnine. It is used in folk medicine as an aphrodisiac and tonic. It also has acquired a certain significance in homeopathy (Strychnos ignatii hom. HAB1). Ignatius beans require a prescription and may be obtained only from a pharmacy. Homeopathic preparations (mother tincture up to and including D3) also require a prescription.

The seeds (faba febrifuga, faba indica, faba sancti ignatii, fabae St. Ignatii, semen ignatii, ignatii semen, Ignatius beans) contain 2.5 to 4% alkaloids (sometimes as much as 5.6%), of which some 45 to 60% is strychnine. Brucine, caffeic acid, and chlorogenic acid are also present. The therapeutic single dosage is given as 0.1 g and the total daily dosage as 0.3 g (Roth et al. 1994, 682*).

An aphrodisiac with psychoactive effects (single dosage) consists of 12.5 mg of yohimbé extract (Pausinystalia yohimba), 12.5 mg of Ignatius bean extract, 0.3 mg of atropine methonitrate, and 3.3 mg of ephedrine HCL (formerly registered as the medicine Tonaton®, to treat hypotonia of the bladder).

Strychnos usambarensis Gilg [syn. Strychnos cooperi Hutchinson et M.B. Moss, Strychnos distichophylla Gilg, Strychnos micans S. Moore]—little monkey orange, umuhoko


This species is one of the three most common members of the genus Strychnos in Africa. A tree form that can grow from 3 to 15 meters in height is found throughout eastern and southern Africa. A climbing bush form that can attain a length of over 70 meters (!) occurs in Zaire, the Congo, and West Africa. The Banyambo hunters of Rwanda use the roots and leaves of the tree form to make an arrow poison with curare-like effects (due to the presence of the alkaloids curarine, calebasin, dihydrotoxiferin, and afrocurarine). The leaves have been found to contain sixteen indole alkaloids of the usambarane type. Considerable amounts of harmane have been found in the stem bark of both forms (Quetin-Leclercq et al. 1991). It is possible that the bark of this Strychnos species may have psychoactive uses (cf. ayahuasca analogs).


The Ignatius bean (Strychnos ignatii) contains the potent substance strychnine. (Photograph: Karl-Christian Lyncker)



Botanical illustration of Strychnos ignatii. (From Köhler’s Medizinalpflanzen, 1887/89)




See also the entries for Strychnos nux-vomica and strychnine.


Bauer, Wilhelm P. 1965. Der Curare-Giftkreis im Lichte neuer chemischer Untersuchungen. Baessler-Archiv, n.f., 13:207–53.


Le Roy, Alexander. 1922. The religion of the primitives. New York: Macmillan.


Ohiri, F. C., R. Verpoorte, and A. Baerheim Svendsen. 1983. The African Strychnos species and their alkaloids: A review. Journal of Ethnopharmacology 9:167–223.


Quetin-Leclercq, Joëlle, Luc Angenot, and Norman G. Bisset. 1990. South American Strychnos species: Ethnobotany (except curare) and alkaloid screening. Journal of Ethnopharmacology 28:1–52.


Quetin-Leclercq, Joëlle, Monique Tits, Luc Angenot, and Norman G. Bisset. 1991. Alkaloids of Strychnos usambarensis stem bark. Planta Medica 57:501.


Richard, C., C. Delaude, L. Le Men-Olivier, J. Lévy, and J. Le Men. 1976. Alcaloides du Strychnos variabilisPhytochemistry 15:1805–6.


Thiel, Josef F., Jürgen Frembgen, et al. 1986. Was sind Fetische? Frankfurt/M.: Museum für Völkerkunde. (Exhibit catalogue.)