Flax / Linseed
Linum usitatissimum
Other names: Flax / Linseed, Flax (Linseed), Flax / linseed
Edible plantPhoto credit: Köhler's Medizinal-Pflanzen (Plate 16); via Biodiversity Heritage Library
Safety information
Safety information
Toxicity: Abdominal bloating common; rare, sometimes severe allergic reactions. Large amounts of raw/unripe seed contain cyanogenic glycosides - normal culinary/therapeutic amounts of mature seed considered safe; very large raw intakes not advised. | Mild — immature seeds may be toxic; oil goes rancid easily. | Low at food amounts. (General knowledge: flaxseed contains cyanogenic glycosides; large raw amounts with low fluid can cause issues — moderation advised.)
Contraindications: Must NOT be used with swallowing difficulty/oesophageal narrowing (choking/obstruction risk). Constipation contraindications: undiagnosed rectal bleeding, bowel obstruction/stenosis, ileus, megacolon, sudden persistent change in bowel habit. Restricted to >12 (EMA). Take with plenty of fluid. | Take whole seed with plenty of water; do not use immature seed. | (General knowledge) bowel obstruction; take with adequate fluid; caution with large amounts in pregnancy.
Interactions: Mucilage may delay absorption of concurrently taken oral drugs - separate dosing by ~30-60 min; theoretical additive effect with antidiabetic/lipid drugs. | None specifically noted. | (General knowledge) mucilage may slow absorption of co-taken oral drugs; mild estrogenic lignans.
Pregnancy & breastfeeding: Not specifically addressed; lignans have weak phytoestrogen activity. | (General knowledge) caution with large amounts.
Evidence level
Supported by clinical trials in humans.
Preparations
oil · seed
Part used: seed
Traditional use: Traditionally taken as a source of omega-3 essential fatty acids.
How to prepare (traditional): Oil pressed from the seed; convenient but goes rancid easily, so it should be stored carefully.
Dosage note (descriptive only): The book suggests 1–2 tsp daily as a nutritional supplement.
other · seed
Part used: seed
Traditional use: Traditionally taken as a bulk laxative and to support estrogen balance at menopause.
How to prepare (traditional): Cracked or ground seed taken with water (whole seeds support elimination; cracked/ground needed for other benefits).
Dosage note (descriptive only): The book suggests 1–2 tbsp daily with water to help relieve menopausal symptoms; bulk-laxative use requires about 5 times the seed volume of water.
poultice · seed
Part used: seed
Traditional use: Traditionally applied as a poultice to boils and carbuncles to soften skin and draw out matter.
How to prepare (traditional): Flour (ground seed) mixed with water and used as a poultice; also used in baking as a phytoestrogenic food.
Associated conditions
Edibility
Edible parts: seeds (ground for best digestibility) and oil, in foods | seeds and oil are common foods (baking, smoothies); store ground seed/oil refrigerated | Seed, whole/ground; a common food.
Toxic lookalike warning
Commercial seed is unmistakable; no significant toxic lookalike for sold product.
Nutritional notes
Functional food - alpha-linolenic acid (omega-3), lignans (phytoestrogens), soluble + insoluble fiber, protein. | Rich in omega-3, fibre, protein, lignans; functional food. | Rich in alpha-linolenic acid (omega-3), fiber, lignans (functional food).
Healing traditions
Sources (3)
- Lamberti 1991 + Kananeli 1940, in Mindadze, Masalebi 2020, N1
- EMA/HMPC Lini semen monograph & public summary
- Encyclopedia of Herbal Medicine (book, p.109) — Andrew Chevallier, English, 2016