Black haw
Black haw


Black haw (Viburnum prunifolium) is a shrub native to the woodlands of southern North America. Its root bark has been traditionally used as medicine.

Black haw contains a chemical that might relax the uterus.

People use black haw for menstrual cramps, asthma, diarrhea, labor pain, and many other conditions, but there is no good scientific evidence to support these uses.
When taken by mouth: Black haw stem bark is commonly consumed in foods. Black haw root bark is possibly safe when taken as a medicine.

Special Precautions & Warnings:

Pregnancy: It is possibly unsafe to use black haw when pregnant. It might affect the uterus.

Breast-feeding: There isn't enough reliable information to know if black haw is safe to use when breast-feeding. Stay on the safe side and avoid use.

Aspirin allergy: Black haw contains chemicals called salicylates. These salicylates could trigger an allergic reaction in people with asthma or aspirin allergies.

Kidney stones: Because black haw contains oxalic acid. It might increase stone formation in people with a history of kidney stones.


There is interest in using black haw for a number of purposes, but there isn't enough reliable information to say whether it might be helpful.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
Insufficient evidence Effectiveness definitions

Dosing & administration

Traditionally, black haw has been prepared as a tea or in tinctures. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.

Interactions with pharmaceuticals

It is not known if Black Haw interacts with any medicines. Before taking Black Haw, talk with your healthcare professional if you take any medications.

Interactions with herbs & supplements

Calcium: Black haw contains oxalic acid (oxalate), which can decrease the amount of calcium the body absorbs from supplements.
Iron: Black haw contains oxalic acid (oxalate), which can decrease the amount of iron the body absorbs from supplements.
Zinc: Black haw contains oxalic acid (oxalate), which can decrease the amount of zinc the body absorbs from supplements.

Interactions with foods

Black haw contains oxalic acid (oxalate), which can decrease the amount of calcium, iron, and zinc the body absorbs from foods. has licensed monographs from TRC Healthcare.
This monograph was last reviewed on 26/08/2023 10:00:00 and last updated on 31/10/2020 02:14:59. Monographs are reviewed and/or updated multiple times per month and at least once per year.
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