Supplement analysis backed by scientific evidence · PT

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Moderate evidenceGut health

Ground Flaxseed

A food, not really a supplement: ground flaxseed supplies viscous fiber, ALA and lignans. Randomized trials support modest benefits for constipation, blood pressure and blood lipids.

Evidence last reviewed: August 2026

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What the science says

  • Constipation Moderate evidence

    A randomized trial in a Chinese population found flaxseed supplementation improved functional constipation and quality of life, and smaller randomized trials in constipated patients with type 2 diabetes reported similar results, with flaxseed performing comparably to psyllium.

  • Blood pressure Moderate evidence

    A meta-analysis of randomized controlled trials found flaxseed lowered blood pressure in hypertensive subjects by a few mmHg, an effect that is real but small.

  • Blood lipids Moderate evidence

    A dose-response meta-analysis of randomized trials in people with dyslipidemia-related conditions found small reductions in LDL and total cholesterol, with whole ground seed performing better than flaxseed oil for lipids.

Dosage & safety

Studied doseStudies commonly used 10–30 g per day of ground seed (about 1–3 tablespoons), taken with plenty of water. Whole seeds pass through largely intact — grind them, and store the meal in the fridge.
SafetyGas and bloating are common when starting. Take with fluid; very high intakes can worsen obstruction in people with strictures. The lignans are weakly estrogenic — discuss with a doctor if you have hormone-sensitive cancer. Flaxseed may add to the effect of blood-pressure and blood-thinning medication, and can slow absorption of drugs taken at the same time.

Scientific references

Where to buy

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