hydroxymatairesinol

PhytochemicalLignan

What is it

7-Hydroxymatairesinol (HMR) is a plant lignan extracted from Norway spruce (Picea abies) knotwood. It is sold as HMRlignan and similar branded ingredients, often as a potassium acetate complex, marketed for menopausal and women's health support.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Hot flashes

Limited Evidence

Small randomized trials report reductions in hot flash frequency with HMR lignan. Effect sizes vary.

How it works

After ingestion, HMR is converted by gut bacteria to enterolactone, the same mammalian lignan produced from flaxseed and other plant lignans. Enterolactone has weak phytoestrogenic activity and is studied for hormonal and breast health. Clinical studies of HMR have looked at menopausal hot flashes and breast tissue, with mixed but generally favorable results.

Dosage

Studies have used 36 to 50 mg/day of HMR lignan complex, taken once or twice daily.

When and how to take it

Most studies use 1 or 2 daily doses, with or without food.

1 commercial form

Compare the main delivery options and what they’re best suited for.

HMRlignan-7-hydroxymatairesinol potassium acetate

Standardized branded extract from Norway spruce knotwood.

Converted by gut bacteria to enterolactone.

Safety

Generally well tolerated. Mild GI upset is the most common report. Long-term safety data extend to about 12 months in available studies.

Who should be cautious

Avoid in pregnancy and lactation due to phytoestrogen activity and lack of safety data. Use with care in hormone-sensitive cancers.

Interactions

May interact with hormone-modulating drugs including tamoxifen and aromatase inhibitors. Discuss with oncologist if relevant.

Food sources

Flaxseed (rich source of other plant lignans)

Amount
1 tbsp
%DV
—

Frequently asked questions

Is HMR lignan the same as flaxseed lignan?⌄

Both are converted to enterolactone in the gut, but HMR is a more direct precursor and may produce more consistent enterolactone levels.

Is HMR safe for breast cancer survivors?⌄

Discuss with your oncologist before use. Phytoestrogen activity and clinical implications are not fully settled.

References

hydroxymatairesinol on Wikidata — Wikidata link

hydroxymatairesinol on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on hydroxymatairesinol (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.