Research
Flaxseed lignans for Menopause: Evidence, Interactions and Cautions
Flaxseed lignans is an ingredient used in menopause supplements marketed to women. Below is what it has actually been studied for, how strong that evidence is, the drug interactions and cautions on record, and the primary source our grade rests on — all drawn from the HerWellReport ingredient dataset.
Also sold as: Linum usitatissimum; linseed; secoisolariciresinol diglucoside; SDG lignans
What the evidence says about Flaxseed lignans
The largest trial is a phase III randomised double-blind placebo-controlled study (NCCTG N08C7) of 188 postmenopausal women given a bar containing 410 mg of flaxseed lignans or placebo for six weeks; a little over a third of women in both groups had a 50% fall in hot flush score, and the investigators concluded flaxseed is not effective for hot flushes. NCCIH describes the wider picture as conflicting, with one study suggesting effectiveness while placebo-controlled comparison showed no significant differences. Flaxseed is not mentioned anywhere in the Menopause Society's 2023 nonhormone therapy position statement, so it was not assessed.
The grade "limited for hot flushes; none for stress incontinence" means: limited — One or two small human trials, or trials for a closely related outcome. none — No human trial evidence we could find for this use. Grades are explained in full on our methodology page.
Read the primary source this grade rests on (opens in a new tab).
Flaxseed lignans drug interactions
- anticoagulant and antiplatelet drugs (NCCIH describes this as a theoretical concern rather than a confirmed interaction)
Who should be careful with Flaxseed lignans
- Do not eat raw or unripe flaxseed, which may contain toxic compounds
- take with plenty of water and expect bloating, wind or loose stools at higher doses
- may affect the result of a double contrast barium enema, so tell your radiology team
- discuss with your doctor if you have oestrogen receptor positive breast cancer
Read more on HerWellReport
This entry is generated from row "Flaxseed lignans" of the HerWellReport ingredient dataset (v2.1, updated 2026-09-23). The dataset is free to reuse under CC BY 4.0 — how to cite it. Ingredient evidence is not evidence for any finished product, and nothing here is medical advice.