What Is Cramp Bark (Viburnum)?

Cramp bark is an ornamental plant also known asViburnum opulus. An extract made from its bark and roots is used by some to treat different types of cramps and a variety of other conditions, such as ulcers and kidney stones. However, scientific evidence about such benefits is lacking.

Cramp bark has a long history of being used as an herbal medicine, primarily by Native Americans. The berries of the viburnum plant were sometimes consumed as food, and other parts of the plant were smoked as an alternative to tobacco.

What Is Cramp Bark Used For?

Research has shown that viburnum bark contains several compounds found to enhance health, including ellagic acid, a chemical with antioxidant benefits.

The chemical constituents esculetin and viopudial are known to be antispasmodic. Because of this, alternative medicine practitioners use viburnum bark to treat conditions involving spasms and muscular cramping including:

• Low back pain 
• Menstrual cramps
• Restless legs syndrome
• Tension headaches
• Stomach pain
• Asthma

Cramp bark is also believed to have anti-inflammatory and calming properties, so it is sometimes used to treat:

• General inflammation
• Chronic pain
• High blood pressure

In addition, viburnum bark is said to reduce fluid retention, as it is a mild diuretic.

However, there isn't a lot of scientific research to support these uses, so it is too soon to recommend viburnum as a treatment for any health concern. Research involving cramp bark has been limited so far and has focused on just a few conditions.

Muscle Cramps

Viburnum bark has historically been used in traditional medicine to relieve cramps, which is where it gets the common name cramp bark.

In the 1960s and 1970s, a handful of research studies analyzed the chemical profiles of viburnum bark and found certain compounds present in it may help suppress muscle spasms and reduce muscle tension. In particular, cramp bark's scopoletin has antispasmodic properties that relax smooth muscle tissue.

Despite this and its common use for conditions involving muscle spasms and muscle tension, there is a lack of more recent research on viburnum bark's effectiveness in treating such conditions.

More research and human trials are needed before recommending cramp bark as a muscle relaxer.

Kidney Stones

Limited research has been conducted on the use of cramp bark as a treatment for a condition called hypocitraturia—a known risk factor for the development of kidney stones.

A 2014 study evaluated cramp bark’s potential for treating mild-to-moderate degree hypocitraturic stone patients and found it has similar citrate, potassium, and calcium levels as lemon juice—an alternative treatment for the condition.

While more research is needed, the study authors concluded that cramp bark could be used as an alternative to pharmaceutical treatment of hypocitraturia.

In addition to potentially preventing kidney stones, cramp bark may also be useful in helping to pass kidney stones due to its antispasmodic effect on the smooth muscle of the kidney

A small human study published in 2019 found cramp bark effective for facilitating the passage of kidney stones smaller than 10 millimeters (mm) and recommended its use as an alternative herbal treatment in combination with diclofenac sodium.

However, more rigorous studies are needed before recommending its use for the passage of kidney stones.

Ulcers

Viburnum is rich in antioxidants Vitamins C and E, carotenoids, chlorophylls, polyphenols, and proanthocyanidins that may be beneficial to the gastrointestinal tract lining and help prevent ulcers.

A 2006 study on rats published in the Journal of Physiology and Pharmacology determined that antioxidants found in viburnum fruit may help protect against the gastrointestinal damage associated with ulcer development.

According to the study authors, the herb appears to activate mucosal defense mechanisms to help prevent damage in the stomach and intestines. However, the research is limited to laboratory studies and it is unclear if these benefits translate to humans.

Possible Side Effects

There is currently a lack of clinical trials testing viburnum's safety or health effects, so it's unknown whether cramp bark supplements are safe for long-term use.

Cramp bark contains oxalates, which should be taken into consideration in persons with a history of oxalate stone formation (even though the herb may be useful in passing other types of kidney stones). Note, however, that there has been no documentation of this—it's simply theoretical.

The safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

It's also important to note that self-treating a condition and avoiding or delaying standard care may have serious consequences. If you're considering using this remedy for any health purpose, make sure to consult your healthcare provider first.

Selection, Preparation, and Storage

Viburnum is sold in supplement form in many natural-foods stores, drugstores, and shops specializing in dietary supplements. Additionally, viburnum supplements are widely available for purchase online.

There is not enough research about cramp bark to determine a standard dose; recommendations on product labels may vary.

Keep in mind that dietary supplements are largely unregulated by the U.S. Food and Drug Administration (FDA) and are not tested for safety as a matter of course. In some cases, a product may provide ingredients not listed on its label. It may also deliver doses that differ from the specified amount for each herb it contains.

Look for products that have been certified by ConsumerLabs, U.S. Pharmacopeia, or NSF International. Such a "stamp of approval" doesn't guarantee that a product is safe or effective, but it can reassure you that it has been evaluated for quality.

It may be helpful to work with a practitioner knowledgeable in the use of herbal medicines to guide your supplement selection, along with appropriate dosing. Seek out a licensed naturopathic doctor or registered herbalist.

Common Questions

What does cramp bark taste like?
Most describe the taste of cramp bark as bitter. Some also say that it has a strong odor.

What are some other natural remedies for pain?
For help in relieving low back pain, consider the use of capsaicin cream, white willow bark, and/or devil's claw. To soothe menstrual cramps, remedies like raspberry leaf tea and ginger may be beneficial. In addition, many mind-body therapies may help curb chronic pain. Examples include guided imagery, massage, acupuncture, and yoga.