# Goji berry (Lycium barbarum) *Wolfberry; the Chinese *kou-chi* in Stuart’s spelling, its fruit *yang-ju*, its root bark *ti-ku-p’i*, its leaves *t’ien-ts’ai*; *Lycium barbarum* and *Lycium chinense*; German *Teufelszwirn* and *Bocksdorn*, the devil’s thread and the buck’s thorn* **Known today as.** The scarlet berry of *Lycium barbarum* and *Lycium chinense*, thin-leaved shrubs of the nightshade family with long, rod-like, hanging branches and small violet flowers from June to autumn: a common shrub of the northern and western provinces of China, and in Europe a Mediterranean plant much planted and long since run wild. Kind: Plant > **Caution.** A woman stabilised on warfarin drank three or four glasses a day of a concentrated tea of the fruit for four days and her clotting time rose; the two should not be combined. ## What was it used for? In Chinese medicine, by Stuart’s account of the *Pen-ts’ao*, the plant as a whole is tonic, cooling, and constructive, prolonging life, improving the complexion, and brightening the eye. The young shoots and leaves are recommended in all wasting diseases, and as a tea to quench thirst and relieve the symptoms of consumption; the root is given for the kidneys and the sexual organs and as a hemostatic for bleeding gums and wounds; the seeds likewise; and there are extracts, pills, and tinctures. The leaves, soft and thin, can be eaten; the berries are sweet with a rather rough taste. ## What does modern science say? A 2017 review counts more than two thousand years of Chinese use and lists what the berry holds: the *Lycium barbarum* polysaccharides that are its principal active fraction, betaine, phenolics, the carotenoids zeaxanthin and -carotene, a stable glucoside of ascorbic acid, -sitosterol, flavonoids, and the vitamins riboflavin, thiamine, and ascorbic acid; the anti-ageing effects reported for the polysaccharides, it concludes, rest on basic science and need further study. Two trials: in 34 healthy adults, two weeks of a standardised goji juice raised questionnaire ratings of energy, sleep, focus, and contentment while the measured weight, blood pressure, pulse, and visual acuity did not change; and in 150 people of 65 to 70, ninety days of a milk-based goji formulation raised plasma zeaxanthin by 26 percent and antioxidant capacity by 57 percent, and the macula stayed stable where the placebo group’s lost pigment and gained soft drusen, though the authors could find no relation between the two changes. ## Pharmacognosy and toxicology - **Lycium barbarum polysaccharides**: the primary active components of the berry, to which its reported anti-ageing effects are laid - **zeaxanthin**: the carotenoid of the berry, with -carotene; plasma zeaxanthin rose 26 percent in ninety days of a goji formulation - **betaine**: with phenolics, a cerebroside, -sitosterol, flavonoids, a stable glucoside of ascorbic acid, and the vitamins riboflavin, thiamine, and ascorbic acid **Mechanism.** The polysaccharides are reported, by the 2017 review, to act through antioxidant, immunoregulative, and anti-apoptotic activities and by reducing DNA damage, on evidence the authors call basic and in need of further study. The berry’s tea weakly inhibited the enzyme CYP2C9 that clears the active form of warfarin in the laboratory, too weakly, the case report judged, to explain the whole of the clotting change it saw. **Dose.** 120 millilitres a day of a standardised juice for fourteen days in the one general trial; 13.7 grams a day of a milk-based formulation for ninety days in the eye trial; three or four glasses a day of a concentrated tea in the warfarin case. **Standing.** A food with a long medicinal reputation and two small trials behind it, one of questionnaire ratings and one of the macula; the eye trial’s authors could not relate the change they measured to the zeaxanthin they also measured. ## What lore surrounds it? A plant of two names in two worlds: the devil’s thread of German hedges, where Thomé found it escaped from gardens, and the life-prolonging *kou-chi* of the Chinese books, whose fruit, Stuart says, the Chinese hold to brighten the eye. The one clinical trial of it on the eye, ninety days of goji in milk, is among the few in which an old claim and a modern measurement have met. ## What did the older authorities say? **Pliny.** The *lycium* of the ancients was not this plant but a medicament of eighteen remedies boiled from the bitter branches and roots of a thorn, three days in a copper vessel until it had the consistency of honey, the Indian sort the best: for the eyes, for itch-scabs, for the gums, for coughs, and for wounds. Linnaeus gave the old name to the genus of the goji. **The *Pen-ts’ao*, as G. A. Stuart reports it.** Porter Smith had mistaken the *kou-chi* for a barberry; Stuart sets it right as a solanaceous shrub. Its general action “is considered to be tonic, cooling, constructive, prolonging life, improving the complexion, and brightening the eye”; the shoots in wasting disease, the leaves as a tea, the root for the kidneys and for bleeding. **O. W. Thomé.** In the German flora the common *Teufelszwirn*, *Lycium barbarum*, is an unarmed or thorny shrub with thin, rod-like, overhanging branches, a light red to violet corolla, stamens standing out of it, and a scarlet berry, flowering from June into autumn to a height of about two and a half metres: a plant of the Mediterranean region, much planted and much run wild. ## Sources - Stuart, G. A. (1911). *Chinese Materia Medica: Vegetable Kingdom*, “Lycium chinense,” pp. 250–251. Internet Archive, b31350033. - Thomé, O. W. (1889). *Flora von Deutschland, österreich und der Schweiz*, Bd. 4, “Gattung 641: Lycium,” and Tafel 490. Internet Archive, profdrthomesflor41889thom. - Pliny the Elder. *The Natural History*, trans. John Bostock and H. T. Riley, vol. 5, Book 24, chs. 76–77, “Lycium: eighteen remedies.” Project Gutenberg, 60688. - Gao, Y., Wei, Y., Wang, Y., Gao, F., & Chen, Z. (2017). *Lycium barbarum*: a traditional Chinese herb and a promising anti-aging agent. *Aging and Disease* 8: 778–791. doi:10.14336/AD.2017.0725 - Amagase, H., & Nance, D. M. (2008). A randomized, double-blind, placebo-controlled, clinical study of the general effects of a standardized *Lycium barbarum* (goji) juice, GoChi. *Journal of Alternative and Complementary Medicine* 14: 403–412. doi:10.1089/acm.2008.0004 - Bucheli, P., et al. (2011). Goji berry effects on macular characteristics and plasma antioxidant levels. *Optometry and Vision Science* 88: 257–262. doi:10.1097/OPX.0b013e318205a18f - Lam, A. Y., Elmer, G. W., & Mohutsky, M. A. (2001). Possible interaction between warfarin and *Lycium barbarum* L. *Annals of Pharmacotherapy* 35: 1199–1201. doi:10.1345/aph.1Z442 --- *Goji berry.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-04. The Thinking Press. https://thethinkingpress.org/materia-medica/goji-berry Historical description, not medical advice.