# Cramp Bark (Viburnum opulus)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/cramp-bark
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-20
**Evidence Score:** 2 / 10
**Category:** European
**Also Known As:** Viburnum opulus, European Cranberrybush, Guelder Rose, Water Elder, Snowball Tree, High Cranberry, Rose Elder, Whitten Tree

## Overview

Cramp bark (Viburnum opulus) contains the antispasmodic compounds scopoletin and viopudial, which relax smooth and skeletal muscle tissue by inhibiting calcium-mediated muscle contractions. It has been used in European herbal medicine for centuries primarily to relieve uterine and menstrual cramping, though modern clinical trial evidence remains limited.

## Health Benefits

• Traditional antispasmodic for menstrual cramps and muscle spasms - evidence based on historical use only, no clinical trials identified
• Potential [antioxidant activity](/ingredients/condition/antioxidant) - preliminary evidence from in vitro assays (ORAC, FRAP, ABTS) showing radical scavenging capacity
• Traditional use for uterine pain relief - supported by 200+ years of European herbalism but lacks clinical validation
• May help with [muscle relaxation](/ingredients/condition/sleep) - patent data suggests verbenalin content (~7.7% in extracts) as active marker but no human studies
• Traditional remedy for colic and nervous conditions - historical use documented in Native American and European herbalism without clinical evidence

## Mechanism of Action

Scopoletin, a coumarin glycoside in cramp bark, acts as a smooth muscle relaxant by blocking voltage-gated calcium channels, reducing intracellular calcium availability needed for muscle contraction. Viopudial, a bitter iridoid, has demonstrated spasmolytic activity by modulating autonomic nerve signaling at smooth muscle tissue. Additionally, flavonoids such as amentoflavone may contribute antioxidant activity by scavenging [reactive oxygen species](/ingredients/condition/antioxidant) via hydrogen atom transfer and single electron transfer mechanisms, as measured in ORAC, FRAP, and ABTS in vitro assays.

## Clinical Summary

No peer-reviewed randomized controlled trials specifically evaluating cramp bark in human subjects for menstrual pain or muscle spasm relief have been identified in the published literature. Evidence for its antispasmodic effects derives primarily from in vitro studies demonstrating calcium channel antagonism by scopoletin and spasmolytic activity of viopudial in isolated tissue preparations. Its [antioxidant](/ingredients/condition/antioxidant) capacity has been quantified in cell-free assays, but these findings have not been translated into clinical outcomes data. The overall evidence base remains at a traditional-use and preclinical level, warranting caution before drawing firm efficacy conclusions.

## Nutritional Profile

Cramp Bark (Viburnum opulus) is a medicinal bark rather than a nutritional food source; macronutrient content (protein, fat, carbohydrate) is negligible in therapeutic preparations. Bioactive compounds drive its pharmacological interest: Scopoletin (coumarin glycoside) is the primary active constituent, reported at approximately 0.1–0.5% dry weight in bark extracts, acting as a smooth muscle relaxant. Viopudial (an iridoid) is present at trace levels and contributes to antispasmodic activity. Isovaleric acid and its esters (including borneol isovalerate) are volatile constituents identified in bark, contributing to muscle-relaxing properties. Chlorogenic acid and other hydroxycinnamic acid derivatives provide phenolic [antioxidant activity](/ingredients/condition/antioxidant), with total phenolic content reported at 15–40 mg GAE/g dry extract in preliminary assays. Tannins (hydrolyzable type) are present at approximately 2–4% dry weight, contributing astringent properties. Flavonoids including amentoflavone and kaempferol glycosides have been identified at low concentrations (<1% dry weight). Saponins are present in minor quantities. Vitamin C has been detected in the fruit (not bark) at approximately 50–80 mg/100g fresh weight. Mineral content of bark includes modest potassium, calcium, and magnesium, but concentrations are insufficient to contribute meaningfully to dietary intake. Bioavailability data is largely absent from clinical literature; scopoletin bioavailability is inferred from related coumarin pharmacokinetic studies suggesting reasonable oral absorption, but bark-specific human pharmacokinetic studies have not been published.

## Dosage & Preparation

No clinically studied dosage ranges available due to absence of human trials. Commercial preparations include alcohol-free liquid extracts (1:3 w/v dry bark in glycerin-water) and bark powders, but standardization is limited. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Cramp bark is generally considered well tolerated at typical herbal doses (300–500 mg dried bark extract, 2–3 times daily), with mild nausea and gastrointestinal upset reported at higher doses. Due to its uterine-relaxing spasmolytic activity, it is contraindicated in early pregnancy despite traditional use for threatened miscarriage, as the safety profile in pregnant women has not been established by clinical research. Its coumarin content (scopoletin) raises a theoretical interaction concern with anticoagulant medications such as warfarin, as coumarins can potentiate blood-thinning effects, though direct pharmacokinetic interaction studies are lacking. Individuals with aspirin sensitivity or salicylate intolerance should use caution, as Viburnum opulus bark contains salicin-related compounds.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses on cramp bark were identified in the research. Available studies (PMC6684545, PMC7694363) focus only on phytochemical composition and in vitro [antioxidant](/ingredients/condition/antioxidant) assays rather than human outcomes.

## Historical & Cultural Context

Cramp bark has been used in European traditional medicine for over 200 years as documented in the British Herbal Pharmacopoeia, primarily as an antispasmodic for menstrual cramps and muscle spasms. Native American and early European herbalists employed bark decoctions and tinctures for cramps, colic, and nervous conditions.

## Synergistic Combinations

Valerian, Passionflower, Magnesium, Black Cohosh, Ginger

## Frequently Asked Questions

### What is cramp bark used for?

Cramp bark is primarily used in European herbal medicine to relieve uterine cramping associated with menstruation and to reduce skeletal and smooth muscle spasms. Its active compounds scopoletin and viopudial exert spasmolytic effects by blocking calcium-mediated muscle contractions, though this is supported by traditional use and in vitro data rather than human clinical trials.

### How does cramp bark work for menstrual cramps?

Cramp bark's coumarin compound scopoletin inhibits voltage-gated calcium channels in uterine smooth muscle cells, reducing the intracellular calcium influx required to sustain muscle contractions, thereby alleviating cramping. The iridoid viopudial complements this by modulating autonomic nerve signaling at the smooth muscle level. These mechanisms are established in isolated tissue and animal models but have not been confirmed in human clinical trials.

### What is the recommended dosage of cramp bark?

Traditional herbal guidelines typically suggest 300–500 mg of dried cramp bark extract taken 2–3 times daily, or 2–4 mL of a 1:5 tincture up to three times daily. Standardized extracts are not commercially established because no clinical trials have defined a validated therapeutic dose. Practitioners generally recommend starting at the lower end and titrating based on individual response.

### Is cramp bark safe during pregnancy?

Despite its historical use to manage threatened miscarriage, cramp bark is not considered safe to use during pregnancy without medical supervision because its uterine spasmolytic activity has not been evaluated in controlled human pregnancy studies. The same smooth muscle relaxing mechanism that relieves menstrual cramps could theoretically affect uterine tone at critical stages of pregnancy. Pregnant women should consult a qualified healthcare provider before using any Viburnum opulus preparation.

### Does cramp bark interact with any medications?

Cramp bark contains scopoletin, a coumarin compound, which raises a theoretical pharmacodynamic interaction risk with anticoagulant drugs such as warfarin or heparin by potentially enhancing blood-thinning effects, though direct human pharmacokinetic studies have not confirmed this interaction. Its salicin-related constituents may also amplify the effects of aspirin or non-steroidal anti-inflammatory drugs (NSAIDs). Patients taking blood thinners, antihypertensives, or sedative medications should consult a physician before use due to additive effect risks.

### What is the difference between cramp bark and black haw for menstrual support?

Both cramp bark (Viburnum opulus) and black haw (Viburnum prunifolium) are traditional antispasmodics used for menstrual discomfort, but they are distinct species with slightly different traditional applications. Cramp bark is primarily associated with European herbalism and general muscle spasms, while black haw has stronger historical use specifically for uterine and ovarian pain in North American traditions. Neither has robust clinical evidence comparing their relative effectiveness, so choice often depends on availability and individual practitioner preference.

### Who should avoid cramp bark supplementation?

Individuals taking blood thinners or anticoagulant medications should consult a healthcare provider before using cramp bark, as some Viburnum species may have mild anticoagulant properties. People with a history of kidney stones should also exercise caution, as cramp bark contains compounds that may affect mineral metabolism. Those allergic to plants in the Adoxaceae family should avoid this ingredient.

### How strong is the scientific evidence supporting cramp bark's effectiveness?

The evidence for cramp bark is primarily historical and based on 200+ years of European traditional use rather than modern clinical trials—no randomized controlled studies have validated its antispasmodic effects in humans. While preliminary in vitro research suggests antioxidant activity through radical scavenging, this does not demonstrate clinical benefit for menstrual cramps or muscle spasms. Current use relies on traditional knowledge and anecdotal reports, making it important to manage expectations about efficacy.

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