What is Cramp Bark?

C. Martin

Cramp bark is a colloquial name for shrubs identified by the scientific name of Viburnum opulus. It is also known by a number of other common names, including Dog Rowan Tree, King's Crown, May Rose, Black Haw and Cranberry Tree. This shrub, which is native to the British Isles, and has been introduced into some parts of America and Canada, can grow quite large, sometimes up to 16 feet (five meters) tall and 16 feet (five meters) in width.

Cramp bark may be used to treat premature labor by stopping uterine contractions.
Cramp bark may be used to treat premature labor by stopping uterine contractions.

This shrub is a member of the family of plants called Caprifoliaceae, which includes honeysuckle shrubs, and like some species of honeysuckle it bears white flowers that can grow up to five inches (about 13 cm) in size. The flowers give rise to red berries that are edible if cooked. These berries contain large quantities of vitamin C, and are sometimes eaten in a similar way to cranberries.

Cramp bark can be used to treat uterine cramps or period pains.
Cramp bark can be used to treat uterine cramps or period pains.

Cramp bark tea has long been used to treat uterine cramps, or period pains. It contains a substance called scopoletin, which is a kind of muscle relaxant that tends to ease spasmodic muscle contractions. Cramp bark tincture has also been used to treat the premature onset of labor in pregnant women, when it may be successful in stopping uterine contractions that have commenced too early. Cramp bark herb extracts are sometimes marketed to pregnant women as an aid that may help to strengthen the uterine muscles in preparation for labor. As with any herbal supplements, pregnant women are usually advised to check with their physician prior to taking any supplement of this nature.

Diarrhea is one possible side effect of cramp bark.
Diarrhea is one possible side effect of cramp bark.

Cramp bark extract is usually prepared by stripping bark from the roots of the shrub rather than from the branches. The bark thus obtained may then be dried and powdered. Alternatively, the bark may be soaked in a fluid such as alcohol or another solute, to obtain a tincture containing the active substance.

Cramp bark may be used to relieve leg cramps.
Cramp bark may be used to relieve leg cramps.

Other cramp bark benefits may include relieving muscular pain such as cramps in the leg or neck, and lowering blood pressure. The effect on blood pressure is believed to be due to the relaxation of the muscular walls of the blood vessels. Cramp bark side effects may include stomach problems such as nausea, diarrhea, and vomiting. Skin rashes may also be experienced. Side effects are usually only seen if the cramp bark extract is taken in high dosages, however, and at low dosages many people report no adverse side effects.

Cramp bark may be helpful in lowering blood pressure.
Cramp bark may be helpful in lowering blood pressure.
Cramp bark may help treat neck pain.
Cramp bark may help treat neck pain.

You might also Like

Readers Also Love

Discussion Comments


@geekish - I would just check out the local specialty stores, for the sole reason you will probably find lots of other really neat items and teas.

I like you am always amazed when I have been eating or drinking something and I find out it has added benefits in addition to the fact it tastes good.


What a fantastic herbal tea that I had never heard of before! I actually wish they would name more herbs after the things they help like Chamomile Inflammation Relieving Tea, I guess then it would probably have to be government regulated and tested so that would make it much easier said than done!

Can you buy cramp bark herbal teas in a regular grocery store or do you need to find a specialty store for this one?


I like to drink the juice of cramp bark shrubs and make jam from the pulp. Before I do either of these, I have to crush them.

First, I freeze the berries. That way, when I thaw them out, they will be softer. Next, I put them in a big bucket, add water, and smash them all up with a heavy piece of wood.

When they are all mashed up, I pour them through a colander. This separates the pulp from the skin and seed. Then, I strain the pulp using a cheesecloth to separate the juice from the flesh.


Cramp bark grows in my neighbor’s yard. She calls it a black haw tree. It has beautiful clusters of star-shaped white flowers that make it look like a crepe myrtle tree from a distance.

The bright green leaves really make it stand out among the other trees with duller leaves. In the fall, its leaves turn a beautiful red color. The neighbor a few houses down from me has several black haw trees, and some of them turn orange and yellow in autumn. I don’t know what determines the color that they will turn.

This tree grows in a spot that is shady most of the day. It gets maybe a couple of hours of sunlight. The tree seems to appreciate the shade.


I grew up in a family of four sisters, and we were only a year apart. So, several of us shared menstruation woes in our teens.

Three of us found relief by using cramp bark. It didn’t help the fourth sister at all. She spent her menstrual days in misery, while we led normal lives during ours.

Our mom finally took her to a gynecologist to see what could be done. She discovered that she had polycystic ovaries. The cramp bark didn’t help, because she wasn’t having cramps at all.


Cramp bark was a popular menstrual pain remedy among my circle of friends in high school. One girl used it and told me about it, and then word got passed around until all of us were using it.

The label on the bottle said to start using it the day we first noticed spotting. That way, by the time the heavy flow hit, which would normally be the following day, we would have enough of it in our systems to combat the cramps. The label also said to only use it as needed after that.

One girl used it during the entire seven days her period lasted, and she suffered side effects. She had some pretty intense diarrhea and nausea.


@SZapper - I don't really get cramps, but I'm going to pass that information on to a few of my friends. I know they would prefer to take an herbal tincture instead of pain relievers.

I'm kind of surprised I've never heard of anyone eating cramp bark berries. It seems that most people know about the benefits of vitamin C, so I would think these berries would be extremely popular.


I tried cramp bark for my severe period cramps quite awhile ago. It actually did help me a little bit, and I didn't experience and unpleasant side effects.

However, keep in mind I have endometriosis, so my cramps were extremely severe. Just the fact that cramp bark helped me some makes me think it would be very effective for someone with normal cramps.

Post your comments
Forgot password?