Skip to Content

Lettuce Opium

Medically reviewed on Sep 13, 2018

Scientific Name(s):Lettuce opium is a product obtained from the milky white sap of Lactuca virosa L. (wild lettuce) and L. sativa var capitata L. (garden lettuce) but related species are sometimes used. Family: Asteraceae (daisies)

Common Name(s): Wild lettuce , German lactucarium , garden lettuce , lettuce opium , strong-scented lettuce , green endive , acrid lettuce , greater prickly lettuce


Lettuce opium has been used as a topical antiseptic, as folk medicine to ameliorate a variety of conditions, and as a narcotic substitute or enhancer. It is also a mild sedative and hypnotic. There is little evidence to support its use for any indication.


There is no recent clinical evidence to support specific dose recommendations.


Contraindications have not yet been identified.


Information regarding safety and efficacy in pregnancy and lactation is lacking.


None well documented.

Adverse Reactions

Lettuce opium contains sesquiterpene lactones; therefore, oral ingestion may be associated with allergic reactions.


Injection of wild lettuce opium and valerian root has been associated with transient fevers, chills, abdominal pain, flank and back pain, neck stiffness, headache, leucocytosis, and mild liver function abnormalities in 3 young adults.


Widely cultivated, lettuce flowers from July to September. This biennial herb grows to 1.8 m. The large leaves can attain lengths of 0.46 m. The stalks are rich in a milky-white sap that flows freely when the stems are broken.


Lettuce opium has been used in folk medicine for indications ranging from aiding circulation to treating swollen genitals. In Europe, it is used as a substitute for opium in cough mixtures. 1 In homeopathy, a tincture has been used for laryngitis, bronchitis, asthma, cough, and urinary tract infections. 2 The juice of the stem covering yields a medicinal extract known as thridace, the use and efficacy of which is widely disputed. 3

In Chinese medicine, lettuce preparations have been widely used. The dried juice has been recommended as a topical wound antiseptic, and the seeds have been used as a galactogogue (to increase the flow of milk in nursing mothers). It has been claimed that the flowers and seeds are effective in reducing fevers. 4 More recently, lettuce opium products have been marketed as legal highs or narcotic substitutes intended to be smoked alone or in combination with marijuana to enhance potency and flavor. 5 Its analgesic and sedative attributes seem more based on fiction than fact.


Some confusion exists regarding the nomenclature of the products derived from L. virosa and related plants. Flowering lettuce plants contain large amounts of a milky-white sap, which has a bitter taste and strong opiate-like odor. When the juice is collected and is exposed to air, it turns a brownish color. This substance is called lactucarium, a mixture of compounds to which the touted narcotic properties of the product have been ascribed. Lactucarium has been reported to contain approximately 0.2% lactucin, a sesquiterpinoid lactone. Additionally, the mixture contains a volatile oil, caoutchouc, mannitol, and lactucerol (taraxasterol) (approximately 50%). Lactucerin, also found in the latex, is the acetyl derivative of taraxasterol, a widely distributed triterpene. 4 , 6

Reports that lactucarium contains hyoscyamine have been refuted. 7 A report that L. virosa contains N-methyl-beta-phenylethylamine 8 also has been refuted. 5

Uses and Pharmacology

Hallucinogenic Effects

A variety of legal, alternate “hallucinogenic” products containing lettuce opium have been available on the market. Brand names of such products include Lettucine , Black Gold , Lettucene , Lettuce Hash , and Lopium . These products contain a lettuce derivative or lactucarium and are smoked in pipes or heated in small bowls, and the vapors are inhaled. These extracts are sometimes combined with damiana distillates, African yohimbe bark, or catnip distillates.

Animal data

Research reveals no animal data regarding the use of lettuce opium for hallucinogenic effects.

Clinical data

The hallucinogenic effect is usually mild and appears to be related to the degree of user expectation. There is no pharmacologic basis for the purported hallucinogenic effects of lettuce opium.

Other uses

Lettuce leaf cigarettes have been marketed as nicotine-free tobacco substitutes. Support for such alternatives has been variable because of slow acceptance of the unique flavor and the lack of a nicotine-induced kick.

Phytochemical and biological screening of several Lactuca species indicates that the genus has no antimicrobial activity, slight antitumor activity, and can produce gross CNS effects in mice. 9 , 10 However, the Lactuca species has resistance to viruses, bacteria, and fungi ( Bremia lactucae ). 11

While lactucin and lactucopicrin have been reported to have depressant and sedative activity on the CNS, these compounds are chemically unstable; commercial lactucarium contains little, if any, of these. 12 Latex of L. sativa has been shown to inhibit the growth of Candida albicans in vitro. 13 Extracts of L. sativa resulted in hypotension when administered to dogs. 5


There is no recent clinical evidence to support specific dose recommendations.


Information regarding safety and efficacy in pregnancy and lactation is lacking.


None well documented.

Adverse Reactions

No reports of clinically important adverse effects caused by smoking lettuce opium have been reported. However, a possible association exists between lettuce ingestion and a localized oral allergic reaction. 14


Three young adult drug users became ill with fevers, chills, abdominal pain, flank and back pain, neck stiffness, headache, leucocytosis, and mild liver function abnormalities after injecting wild lettuce opium and valerian root. However, all 3 patients recovered within 3 days. 15


1. Lewis WH. Medical Botany . New York, NY: J. Wiley and Sons; 1977.
2. Schauenberg P, Paris F. Guide to Medicinal Plants . New Canaan, CT: Keats Publishing; 1977.
3. Grieve MA. Modern Herbal . New York, NY: Dover Publications; 1971.
4. Brown JK, Malone MH. Legal highs-constituents, activity, toxicology and herbal folklore. Pacific Information Service on Street Drugs . 1977;5:36.
5. Huang ZJ, Kinghorn AD, Farnsworth NR. Studies on herbal remedies I: analysis of herbal smoking preparations alleged to contain lettuce ( Lactuca sativa L.) and other natural products. J Pharm Sci . 1982;71:270-271.
6. Bachelor FW, Ito S. A revision of the sterochemistry of lactucin. Can J Chem . 1973;51:3626.
7. Willaman JJ, Li HL. Lloydia . 1970;33:1.
8. Marquardt P, Classen HG, Schumacher KA. N-Methylphenethylamine, an indirect sympathicomimetic agent in vegetables. Arzneimittelforschung . 1976;26:2001-2003.
9. Bhakuni DS, Dhar ML, Dhar MM, Dhawan BN, Gupta B, Srimal RC. Screening of Indian plants for biological activity. Indian J Exp Biol . 1971;9:91-102.
10. Fong HH, Farnsworth NR, Henry LK, Svoboda GH, Yates MJ. Biological and phytochemical evaluation of plants. X. Test results from a third two-hundred accessions. Lloydia . 1972;35:35-48.
11. Chupeau MC, Maisonneuve B, Bellec Y, Chupeau Y. A Lactuca universal hybridizer, and its use in creation of fertile interspecific somatic hybrids. Mol Gen Genet . 1994;245:139-145.
12. Tyler VE. The New Honest Herbal . Philadelphia, PA: G.F. Stickley Co.; 1987.
13. Moulin-Traffort J, Giordani R, Regli P. Antifungal action of latex saps from Lactuca sativa L. and Asclepias curassavica L. Mycoses . 1990;33:383-392.
14. Bernton HS. Oral allergy after lettuce ingestion. JAMA . 1974;230:613.
15. Mullins ME, Horowitz BZ. The case of salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol . 1998;40:290-291.

Copyright © 2009 Wolters Kluwer Health

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.