# Linseed (Linum usitatissimum) *Flaxseed; the seed of flax, *Linum usitatissimum* of Linnaeus; the Greek *linon* of Dioscorides; in pharmacy *Lini semen** **Known today as.** The seed of *Linum usitatissimum*, flax, “a graceful little plant with turquoise blue blossoms,” an erect annual one to two feet high with narrow alternate leaves. Each globular capsule holds ten brown, flat, glossy seeds, odourless until powdered, with a mucilaginous taste. The seed coat is rich in mucilage and the seed in a fixed oil, pressed out cold; what remains is oil-cake, and ground, linseed meal. Kind: Plant > **Caution.** Linseed swells: taken without enough fluid it can block the throat or gullet and cause choking, or obstruct the bowel, and chest pain, vomiting, or difficulty swallowing or breathing after taking it need medical help at once. It is not for people with difficulty swallowing or throat problems, narrowings or blockage of the gut, or a sudden change in bowel habit lasting more than two weeks, nor for children under twelve. It can delay the absorption of other medicines, so is taken half an hour to an hour apart from them, and with opioids or loperamide only under medical supervision. Because long-term use may have an oestrogenic effect, it is not recommended for women with hormone-dependent tumours. ## What was it used for? A poultice, a cough medicine, and a laxative. Grieve calls crushed linseed or linseed meal “a very useful poultice, either alone or with mustard,” that “allays irritation and pain and promotes suppuration” in ulcers and inflammation and boils; linseed tea, with honey and lemon, “most valuable” for colds, coughs, and irritation of the urinary organs; and the oil, as a laxative, for gravel and stone. Mixed with lime water as Carron oil, it was laid on burns and scalds. ## What does modern science say? The European Medicines Agency’s herbal committee accepts linseed on clinical evidence, as ‘well-established use,’ for habitual constipation and where an easy passage of soft stool is wanted, and as a traditional demulcent for mild stomach and gut discomfort (monograph of 2015). Its assessment report finds the seed about a quarter bulk material, mucilage and fibre, with 30 to 45 per cent fatty oil, 20 to 27 per cent protein, lignan precursors, and 0.1 to 1.5 per cent cyanogenic glycosides. A 2024 meta-analysis of 54 trials found flaxseed supplements lowered the inflammatory markers C-reactive protein and interleukin-6. ## Pharmacognosy and toxicology - **mucilage**: with fibre, about a quarter of the seed, in the seed coat - **fatty oil**: 30 to 45 per cent - **cyanogenic glycosides**: 0.1 to 1.5 per cent - **lignan**: precursors **Mechanism.** It swells: taken without enough fluid it can block the throat, gullet, or bowel, and it can delay the absorption of other medicines. **Standing.** European Union herbal monograph (2015): well-established use for habitual constipation, and traditional use as a demulcent for mild stomach and gut discomfort. ## What lore surrounds it? Flax seeds and woven linen, Grieve writes, have been found in Egyptian tombs, and the plant is so old in cultivation that its origin cannot be traced. The fine linen of the Bible was spun from it, it was the crop the plague of hail struck in Exodus, and Rahab hid the spies under flax on her roof; Folkard reports that the research of his day took the flax of the ancients to be the narrow-leaved species. In the Middle Ages its flowers were believed to protect against sorcery; the Bohemians held that seven-year-old children who danced among flax would become beautiful; and in Teutonic myth the goddess Hulda first taught mortals to grow it, spin it, and weave it, while Folkard gives the blue flower to Bertha, “whose blue eyes shine in its calyx.” ## What did the older authorities say? **Dioscorides.** The seed boiled with honey, oil, and a little water, he says, has the same strength as fenugreek, “dispersing and softening all inflammation inwardly and outwardly,” and applied raw with saltpetre and figs it takes away sunburn. **Pliny, as Grieve quotes him.** “What department is there to be found of active life in which flax is not employed?” He marvelled that a plant brought Egypt close to Italy under sail, and called it audacity “to sow a thing in the ground for the purpose of catching the winds and tempests.” He also held, Grieve says, that flax scorched the ground. ## Sources - Grieve, M. *A Modern Herbal*, “Flax.” As published on botanical.com. - Dioscorides. *De materia medica*, 2-125, in the modern English version of T. A. Osbaldeston and R. P. A. Wood (Johannesburg: Ibidis, 2000), after Goodyer’s translation of 1655. Internet Archive. - Folkard, R. (1884). *Plant Lore, Legends, and Lyrics*, “Flax.” Project Gutenberg, 44638. - European Medicines Agency, Committee on Herbal Medicinal Products. *European Union herbal monograph on Lini semen (Linseed)*. EMA/HMPC/377675/2014, 10 March 2015. - European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Lini semen*. EMA/HMPC/377674/2014, 10 March 2015. - Musazadeh V, et al. (2024). Effects of flaxseed supplementation on inflammatory biomarkers: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials. *Prostaglandins & other lipid mediators*. PMID 38971216. - European Medicines Agency, Committee on Herbal Medicinal Products. *European Union herbal monograph on Lini semen (Linseed)*. EMA/HMPC/377675/2014, 10 March 2015. - European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Lini semen*. EMA/HMPC/377674/2014, 10 March 2015. - Musazadeh V, et al. (2024). Effects of flaxseed supplementation on inflammatory biomarkers: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials. *Prostaglandins & other lipid mediators*. PMID 38971216. --- *Linseed.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-16. The Thinking Press. https://thethinkingpress.org/materia-medica/linseed Historical description, not medical advice.