Omnia SanaCommon names in 24 European languages →
The complete database record: 4 documented constituents, 4 pharmacological actions, 8 traditional / indicated uses, with 21 cited sources.
Botanical Description
Erect annual herb, slender and often branched near the top, growing 30-80 (up to 100) cm tall from a fine taproot. Leaves are alternate, sessile, narrowly lanceolate to linear, blue-green and entire-margined. Flowers are pale blue (occasionally white or pink), five-petalled and borne on slender stalks in loose terminal cymes. The fruit is a small globular capsule ('boll') that splits into ten compartments, each containing one flattened, glossy, red-brown seed.[5]
Habitat & Distribution
Native to the Mediterranean region and the Fertile Crescent, cultivated since prehistory for fibre and oil and now grown worldwide in temperate regions with well-drained, fertile soils and a cool, moist growing season; occasionally found as a naturalised escape on waste and cultivated ground.[5]
Harvesting
Grown as an annual crop, seed is harvested once the capsules ('bolls') have dried and turned brown, typically in late summer, by cutting or combining the whole plant and threshing out the seed. Whole seed stores well; it should only be ground shortly before use, since the oil in ground seed oxidises and turns rancid quickly.[2]
Key Constituents
Flax is the richest dietary source of SDG-type lignans, converted by gut bacteria to the mammalian lignans enterodiol and enterolactone; studied for antioxidant and hormone-modulating activity.
The dominant fatty acid of the seed oil (~50-55% of total oil), a plant-based omega-3 studied for cardiovascular and anti-inflammatory effects.
Concentrated in the seed coat; gives flaxseed its demulcent, laxative, bulk-forming action.
Present at low levels; cooking/roasting reduces them to negligible amounts in normal food use - a theoretical concern only at high raw intakes.
Pharmacological Actions
Traditional & Indicated Uses
inferred from anti-inflammatory action
inferred from digestive action
inferred from anticancer action
more plants for cancer (anticancer research) →detailed sources →
more plants for cardiovascular / heart health →detailed sources →
inferred from digestive action
inferred from anti-inflammatory action
inferred from anti-inflammatory action
Traditional Use & History
Flaxseed has a long history of traditional use as a bulk-forming laxative and demulcent for constipation and irritated gut mucosa, and as a poultice for boils and inflamed skin. Modern interest centres on its lignan (secoisolariciresinol diglucoside) and alpha-linolenic acid content, studied for cardiovascular, metabolic and hormone-related outcomes.[2, 4, 5]
Preparations
Whole seed freshly ground (milled) and taken with plenty of liquid, or stirred into food; grinding is needed to make the oil and lignans bioavailable, as whole seeds largely pass through the gut undigested.
Cold-pressed oil taken as a concentrated source of alpha-linolenic acid (omega-3); lacks the fibre and lignan content of the whole ground seed.
Dosage
Traditional guidance and Duke (2002) suggest 1-2 tablespoons of ground seed with ample water, once or twice daily. Educational reference only, not a prescription.
A randomised placebo-controlled trial titrated flax oil capsules (550 mg alpha-linolenic acid per 1 g of oil) to 12 capsules per day, i.e. up to roughly 12 g of oil daily, over 16 weeks - broadly matching the 1-2 tablespoons (about 10-15 mL) daily often cited for omega-3 intake. That trial was in children and adolescents with bipolar disorder and its primary outcomes were null; it is cited here only as a source for an administered human dose of the oil, not as evidence of benefit. Note the EU herbal monograph on Lini semen covers the SEED, not the oil. Educational reference only, not a prescription.
Safety, Cautions & Contraindications
Flaxseeds are safe for most people at recommended food amounts (1–2 tablespoons ground/day). They must be ground or milled to be bioavailable - whole seeds largely pass through the gut undigested. High fibre content may cause bloating, flatulence, and loose stools, especially if fibre intake is increased rapidly without adequate hydration. Flaxseeds contain cyanogenic glycosides (linamarin, linustatin); cooking or roasting reduces these to negligible levels in normal food amounts. Raw seeds in very large quantities are a theoretical concern, but typical use is safe (EFSA, 2017).
Medication interactions: Flaxseed may reduce absorption of oral medications if taken simultaneously - space flaxseed supplementation 1–2 hours from medications. Omega-3 ALA and lignans may mildly enhance anticoagulant/antiplatelet effects; use caution with blood thinners. Some sources suggest caution with hormone-sensitive conditions due to phytoestrogen (lignan) content, though dietary amounts are unlikely to pose risk (Adolphe et al., 2010).
Pregnancy: Food amounts are generally considered safe; high-dose supplements should be discussed with a clinician due to limited safety data.
Duke (2002) rates flaxseed as +++ with clinical evidence (score 2) for antiatherogenic, hypocholesterolemic, laxative, lipolytic (fat-dissolving), and demulcent activities. Flaxseed's omega-3 fatty acids (ALA) and lignans are associated with reduced cardiovascular risk. Commission E approves flaxseed as a laxative and for mucilaginous protection of inflamed gastrointestinal mucosa. Dose: 1–2 tablespoons ground seed with ample water, twice daily. Whole seeds should be chewed or ground for full medicinal effect. Cyanogenic glycosides are present but at safe levels in normal dietary amounts (Duke, 2002).
Harvest Readiness
[12]
External Identifiers
References & Sources
- Picur, B., Cebrat, M., Zabrocki, J. and Siemion, I.Z (2006) 'Cyclopeptides of Linum usitatissimum', Journal of Peptide Science, 12(9), pp. 569-574. doi:10.1002/psc.779 Preclinical
https://doi.org/10.1002/psc.779 - Basch, E., Bent, S., Collins, J., Dacey, C., Hammerness, P., Harrison, M., Smith, M., Szapary, P., Ulbricht, C., Vora, M. and Weissner, W (2007) 'Flax and flaxseed oil (Linum usitatissimum): a review by the Natural Standard Research Collaboration', Journal of the Society for Integrative Oncology, 5(3), pp. 92-105. doi:10.2310/7200.2007.005 Meta-analysis / review
https://doi.org/10.2310/7200.2007.005 - Chhillar, H., Chopra, P. and Ashfaq, M.A (2020) 'Lignans from linseed (Linum usitatissimum L.) and its allied species: retrospect, introspect and prospect', Critical Reviews in Food Science and Nutrition, 61(16), pp. 2719-2741. doi:10.1080/10408398.2020.1784840 Meta-analysis / review
https://doi.org/10.1080/10408398.2020.1784840 - Ansari, R., Zarshenas, M.M. and Dadbakhsh, A.H (2019) 'A review on pharmacological and clinical aspects of Linum usitatissimum L', Current Drug Discovery Technologies, 16(2), pp. 148-158. doi:10.2174/1570163815666180521101136 Meta-analysis / review
https://doi.org/10.2174/1570163815666180521101136 - Akter, Y., Junaid, M., Afrose, S.S., Nahrin, A., Alam, M.S., Sharmin, T., Akter, R. and Hosen, S.M.Z (2021) 'A comprehensive review on Linum usitatissimum medicinal plant: its phytochemistry, pharmacology, and ethnomedicinal uses', Mini Reviews in Medicinal Chemistry, 21(18), pp. 2801-2834. doi:10.2174/1389557521666210203153436 Meta-analysis / review
https://doi.org/10.2174/1389557521666210203153436 - Musazadeh, V., Abolghasemian, M., Kavyani, Z., Moridpour, A.H., Nazari, A. and Faghfouri, A.H (2024) 'The effects of flaxseed (Linum usitatissimum) supplementation on anthropometric indices: an updated systematic review and meta-analysis of randomized clinical trials', Complementary Therapies in Medicine, 84, pp. 103066. doi:10.1016/j.ctim.2024.103066 Meta-analysis / review
https://doi.org/10.1016/j.ctim.2024.103066 - Mueed, A., Shibli, S., Jahangir, M., Jabbar, S. and Deng, Z (2022) 'A comprehensive review of flaxseed (Linum usitatissimum L.): health-affecting compounds, mechanism of toxicity, detoxification, anticancer and potential risk', Critical Reviews in Food Science and Nutrition, 63(32), pp. 11081-11104. doi:10.1080/10408398.2022.2092718 Meta-analysis / review
https://doi.org/10.1080/10408398.2022.2092718 - Kaithwas, G., Mukherjee, A., Chaurasia, A.K. and Majumdar, D.K (2011) 'Anti-inflammatory, analgesic and antipyretic activities of Linum usitatissimum L. (flaxseed/linseed) fixed oil', Indian Journal of Experimental Biology, 49(12), pp. 932-938. Preclinical
https://scholar.google.com/scholar?q=Anti-inflammatory%2C%20analgesic%20and%20antipyretic%20activities%20of%20Linum%20usitatissimum%20L.%20%28flaxseed/linseed%29%20fixed%20oil - Rafieian-Kopaei, M., Shakiba, A., Sedighi, M. and Bahmani, M (2017) 'The analgesic and anti-inflammatory activity of Linum usitatissimum in Balb/c mice', Journal of Evidence-Based Complementary & Alternative Medicine, 22(4), pp. 892-896. doi:10.1177/2156587217717416 Preclinical
https://doi.org/10.1177/2156587217717416 - Sirotkin, A.V (2023) 'Influence of flaxseed (Linum usitatissimum) on female reproduction', Planta Medica, 89(6), pp. 608-615. doi:10.1055/a-2013-2966 Meta-analysis / review
https://doi.org/10.1055/a-2013-2966 - Thompson, L.U., Chen, J.M., Li, T., Strasser-Weippl, K. and Goss, P.E (2006) 'Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer', 11(10), pp. 3828--3835. doi:10.1158/1078-0432.CCR-04-2326 Randomized trial
https://doi.org/10.1158/1078-0432.CCR-04-2326 - Plants For A Future 'Linum usitatissimum (Flax, Linseed)'. Available at: https://pfaf.org/user/Plant.aspx?LatinName=Linum+usitatissimum Traditional / reference
https://pfaf.org/user/Plant.aspx?LatinName=Linum+usitatissimum - Adolphe, J.L., Whiting, S.J., Juurlink, B.H.J., Thorpe, L.U. and Alcorn, J (2010) 'Health effects with consumption of the flax lignan secoisolariciresinol diglucoside', 103(7), pp. 929--938. doi:10.1017/S0007114509992753 Clinical study
https://doi.org/10.1017/S0007114509992753 - Caligiuri, S.P.B., Edel, A.L., Aliani, M. and Pierce, G.N (2014) 'Flaxseed for hypertension: implications for improved cardiovascular risk', 16(12), pp. 499. doi:10.1007/s11906-014-0499-8 Randomized trial
https://doi.org/10.1007/s11906-014-0499-8 - European Food Safety Authority (2017) 'Safety of cyanogenic glycosides from flaxseed consumed as part of a usual diet', 15(11). doi:10.2903/j.efsa.2017.5026 Preclinical
https://doi.org/10.2903/j.efsa.2017.5026 - Harris, W.S (2012) 'Stearidonic acid as a surrogate for eicosapentaenoic acid in cardiovascular risk reduction: update and recommendation', 70(10), pp. 565--574. Traditional / reference
https://scholar.google.com/scholar?q=Stearidonic%20acid%20as%20a%20surrogate%20for%20eicosapentaenoic%20acid%20in%20cardiovascular%20risk%20reduction%3A%20update%20and%20recommendation - Latvijas valsts mežzinātnes institūts (n.d.) 'Linsēkla Latvijā'. Available at: https://www.silava.lv Traditional / reference
https://www.silava.lv - Pan, A., Sun, J., Chen, Y. et al (2009) 'Effects of a flaxseed-derived lignan supplement in type 2 diabetic patients: a randomized, double-blind, cross-over trial', 4(11). doi:10.1371/journal.pone.0007654 Randomized trial
https://doi.org/10.1371/journal.pone.0007654 - Royal Botanic Gardens, Kew (n.d.) 'Linum usitatissimum L'. Available at: https://powo.science.kew.org/taxon/urn:lsid:http://ipni.org:names:381313-1 Traditional / reference
https://powo.science.kew.org/taxon/urn:lsid:http://ipni.org:names:381313-1 - Gracious, B.L., Chirieac, M.C., Costescu, S., Finucane, T.L., Youngstrom, E.A. and Hibbeln, J.R (2010) 'Randomized, placebo-controlled trial of flax oil in pediatric bipolar disorder', Bipolar Disorders, 12(2), pp. 142-154. doi:10.1111/j.1399-5618.2010.00799.x Randomized trial
https://doi.org/10.1111/j.1399-5618.2010.00799.x - Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
Selected studies & references
All 19 studies in the Knowledge Finder →
This profile is assembled automatically from the Omnia Sana plant database, which we curate by hand. How this site is built.