Cramp Bark Drug Interactions, Uses, Side Effects & More

Interaction report

Drugs that interact with Cramp Bark

0 medications have a known interaction with Cramp Bark, graded by severity. Select any drug for the full evidence-based detail.

We don’t currently list any known drug interactions for Cramp Bark. This doesn’t guarantee none exist — always confirm with your pharmacist before combining supplements with your medications.

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Cramp Bark combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Monograph

Cramp Bark: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed June 2026 ·

The bottom line

Cramp Bark is the dried bark of Viburnum opulus, traditionally used to ease muscle and menstrual cramps. Modern, high-quality human studies are very limited, so its effectiveness is not well proven. If you want to try it, talk with your pharmacist or doctor first, and avoid it during pregnancy because safety is unclear.

Scientific name: Viburnum opulus
Family: Adoxaceae
Part used: Dried bark
Common forms: Tea (decoction), tincture, liquid extract, capsules

People commonly use it for

Menstrual cramps
Muscle spasms
General cramping pain
Stomach or digestive cramps
Easing tension

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally used in traditional medicine, but human safety data are limited.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Cramp Bark comes from the bark of Viburnum opulus, a shrub also known as the guelder rose. It grows in parts of Europe, Asia, and North America. People have used the bark in traditional herbal medicine for a very long time.

As its name suggests, Cramp Bark has mostly been used to try to ease different kinds of cramping, such as menstrual cramps and muscle spasms. It is usually taken as a tea made from the dried bark, or as a tincture or liquid extract. You may also find it in capsules and in herbal blends.

How it works

Cramp Bark contains a mix of natural compounds, including substances such as tannins, scopoletin (a coumarin), and other plant chemicals. Laboratory studies suggest some of these may have a relaxing effect on smooth muscle, which is the type of muscle found in the uterus and the walls of blood vessels and the gut.

This proposed muscle-relaxing or antispasmodic action is the main reason it has been used for cramps. However, these ideas are based largely on test-tube and animal research, and we do not have strong proof that the same effects happen in people at the amounts found in supplements.

Effectiveness

Does Cramp Bark work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 5 uses evaluated

5 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Cramp Bark, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 5 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Diabetes