Black haw (Viburnum prunifolium ), is a shrub or small tree with serrated oval leaves. Its white flowers and dark berries occur in clusters. The stem bark of black haw is approved for use in foods in the United States. It is native to the woodlands of temperate and subtropical parts of North America, Europe, and Asia. Its other names are stag-bush and American sloe. Black haw belongs to the same genus as the guelder rose Viburnum opulus which is also known as cramp bark . The two are sometimes used interchangeably and have similar properties, but black haw is more specific in its effects on the uterus. The actions of black haw are described as antispasmodic, sedative, astringent, muscle relaxant, cardiotonic, uterine relaxant, and anti-inflammatory.
Black haw has been used traditionally for problems related to the female reproductive tract. It acts as a general antispasmodic that may relax skeletal muscle as well, but is particularly effective on the uterus. As such, it is a potential agent to be included in the treatment of threatened miscarriage, menstrual cramps, false labor, and the afterpains of childbirth . The antispasmodic properties of black haw are also reportedly useful for colic , bladder spasms, cramping pain in the bile ducts, diarrhea , and heavy bleeding during menopause . Black haw may also have some ability to lower high blood pressure.
The most common use of black haw is as an antispasmodic for menstrual pain. To relax the uterus and relieve menstrual cramping, the most commonly recommended dose is 5 mL (1tsp) of the tincture in water, taken three to five times daily as needed. Tinctures of black haw are generally prepared by placing an ounce of fresh herb in an ounce of 50% alcohol, and steeping the mixture for six weeks. Alcohol may extract certain chemical components of the herb more or less strongly than water does, so tinctures may exert different levels of activity than teas (generally the least strong preparations) or infusions. Tinctures and other preparations of black haw are commercially available from some herbalists or health food stores.
Black haw is sometimes used to prevent chronic miscarriage. It has been similarly utilized for the condition of irritable uterus occurring in late pregnancy . The reported nervine (nerve-calming) effect of black haw may be useful in addition to its spasmolytic properties. One recommended dose for these indications is 1–2 cups of tea per day as soon as pregnancy is diagnosed. Alternatively, the patient may take 0.5 cup per day of an infusion of black haw. A tea can be prepared with 1 tsp of dried herb in 1 cup of boiling water, steeped for up to 20 minutes. An infusion is prepared by putting 1 oz of black haw in a pint jar, filling the jar with boiling water, and steeping for eight hours. This preparation is thought to act as a uterine relaxant but will not prevent a miscarriage due to abnormalities in the fetus or placenta. Women should consult a health care practitioner knowledgeable about herbal use in pregnancy before using black haw or any other herbal remedy when pregnant.
For afterpains following childbirth, 1 oz of black haw or cramp bark can be combined with 0.5 oz of blue cohosh root and 0.25 oz of dried hops flowers. The mixture of herbs is steeped in a quart of boiling water for eight hours to make an infusion for the relief of uterine pain. This combination is also said to aid milk production and encourage sleep. Small amounts of the infusion are taken as needed.
One of the historical uses of black haw was for the relief of asthma . Evidence from contemporary clinical studies does not support this use, although black haw's activity as a smooth muscle relaxant could theoretically relieve bronchoconstriction. On the other hand, some components of black haw, particularly the salicylates, have the potential to trigger an asthmatic reaction in sensitive individuals. Asthma is a serious condition that should be monitored and managed by a health care provider. Conventional medications are available that are generally safe and proven effective to control asthma.
The bark of the branches and roots of the plant contain the pharmacologically active ingredients of black haw. These components include salicyclic acid, salicin, oxalic acid, tannins, and scopoletin. The latter ingredient is probably the uterine relaxant. The salicylate constituents would contribute to black haw's anti-inflammatory effects. The root bark should be harvested only in the fall. Bark from the branches may be used either in spring or fall.
Fresh plant material from the shrub may be grown or purchased to make teas, tinctures, or infusions. Some of these remedies are described above. These preparations may also be commercially available from professional herbalists or specialty stores.
People who are allergic to aspirin could theoretically have a reaction to black haw, as one of its components is a salicylate (compound related to aspirin). Bleeding time may also be prolonged as a result in patients who take high chronic doses of black haw. Patients with a history of kidney stones should not use this herb, as the oxalic acid it contains could increase the risk of a recurrence of the disorder.
Some sources say that black haw should not be used in pregnancy. Women should consult a health care practitioner experienced in the use of natural remedies for advice on the use of black haw for the prevention of miscarriage or other possible indications for pregnancy.
This species of Viburnum has not been well-studied in regard to its efficacy, side effects, or safety, although it has centuries of traditional use in humans.
There are no identified interactions of black haw with foods, other herbs, or standard medications.
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Jellin, J.M., F. Batz, and K. Hitchens. Pharmacist's Letter/Prescriber's Letter Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Faculty, 1999.
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Weed, Susun. Wise Woman Herbal for the Childbearing Year. Woodstock, NY: Ash Tree Publishing, 1986.