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Limited evidenceWomen's health

Black Haw

A uterine antispasmodic whose entire human record consists of 19th-century clinical reports. Nothing resembling a controlled trial has been published in the modern era.

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What the science says

  • Uterine cramping Limited evidence

    The published human accounts of Viburnum prunifolium for uterine pain and threatened miscarriage are case reports from the 1880s and 1890s. No randomized or placebo-controlled trial exists.

  • Plausible mechanism Limited evidence

    A pharmacology review of botanicals for women's health lists black haw among traditional uterine relaxants and notes that its activity has been characterized only in preclinical work, with no clinical efficacy data.

Dosage & safety

Studied doseNo studied dose. Traditional preparations use 1-2 g of dried root bark as a decoction, or 5 ml of tincture, up to three times daily.
SafetyContains salicin and oxalates; avoid with aspirin allergy and use caution with a history of kidney stones or anticoagulant use. Historically taken in pregnancy, but with no modern safety data it should be avoided there.

How to take it

TimingDuring painful days, up to three times daily.
With food?With food to reduce stomach irritation.
Worth knowingIt is high in oxalates, so give it a miss if you have had calcium oxalate kidney stones.

Interactions

With medications

  • warfarin, DOACs and antiplatelet drugs

    Black haw contains salicin, which may add to bleeding risk. do not combine without medical supervision

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does black haw work for menstrual cramps?

The evidence for black haw is limited to case reports from the 1880s and 1890s; no randomized or placebo-controlled trial exists. Its uterine-relaxing activity has only been characterised in preclinical work.

How much black haw should I take?

Black haw has no studied dose. Traditional preparations use 1-2 g of dried root bark as a decoction, or 5 ml of tincture, up to three times daily with food.

Is black haw safe in pregnancy?

Black haw was historically taken in pregnancy, but with no modern safety data it should be avoided there. It also contains salicin and oxalates, so avoid it with aspirin allergy or a history of calcium oxalate kidney stones.

Can I take black haw with blood thinners?

Do not combine black haw with warfarin, DOACs or antiplatelet drugs without medical supervision, because its salicin may add to bleeding risk.

Scientific references

Related in Women's health

Herbal medicines: what the evidence says (335)