Classic Western antispasmodic with centuries of use for dysmenorrhea and smooth muscle cramps. The clinical trials that exist — and they're good ones — tested a completely different preparation for kidney stones. The gap between traditional and clinical evidence is unusually wide here.
Traditions: Western herbalism, Eastern European folk medicine, Turkish folk medicine
Formally recognized antispasmodic, sedative, and astringent. Indicated for dysmenorrhea, threatened miscarriage, and nervous conditions. Bark decoction and tincture as primary forms.
Leading antispasmodic for conditions characterized by smooth muscle spasm. Felter and Lloyd documented it extensively for uterine cramps, afterpains, and dysmenorrhea. Part used: dried stem bark.
Fruit (berries/juice), not bark, used as taş düşürücü — 'stone-dropping.' Regional specialty of Central Anatolia, also used for hypertension, diabetes, and UTIs. The only V. opulus tradition with published RCT data.
Deeply embedded in Slavic folk culture (Poland, Russia, Ukraine). Bark and fruit used for menstrual irregularities, uterine spasms, and cardiovascular conditions.
Two published human trials — both solid — but both tested fruit extract (gilaburu) for kidney stones, not bark for cramps. No RCTs exist for dysmenorrhea or muscle spasm, the primary Western indication. Preclinical mechanism is well-established; clinical gap for traditional use is real.
86 participants with distal ureteral stones ≤10mm. V. opulus fruit extract non-inferior to tamsulosin for overall expulsion. Fewer patients needed extra analgesics (37.2% vs 65.1%, P=.017) and emergency visits (11.6% vs 34.8%, P=.02). Faster expulsion for 5–10mm stones: 7.1 vs 11.8 days (P=.005).
103 participants. Stone expulsion 82% vs 66% with diclofenac alone (P=.026) — 16 percentage point improvement. Average expulsion 5 days faster. 24.5% vs 44% needed additional analgesics (P=.042).
Water extract in mice: 56.6% inhibition of acetic acid-induced pain at 100 mg/kg; 63.2% inhibition at 200 mg/kg. Comparable to morphine at 90 minutes. No significant anti-inflammatory effect in carrageenan model.
Isolated scopoletin as primary antispasmodic compound from bark. Established direct uterine smooth muscle relaxant activity — the mechanistic foundation for the traditional dysmenorrhea indication.
Taste: Bitter and notably astringent. Tannins persist on the palate. Easier to take in a small amount of water or juice than straight.
1:5 in 45% ethanol. Most common commercial form. Higher doses used by German phytotherapy tradition at acute onset of cramping. The 45% ethanol ratio optimizes extraction of coumarins and phenolics.
Simmer bark 10–15 minutes, strain. Bark (cortex) only — not leaves or fruit. Traditional preparation. Full phytochemical profile including volatile constituents that may differ from tincture.
This is the gilaburu (fruit) preparation used in Turkish clinical trials for ureteral stones. Not bark extract. Bark capsules exist commercially but have no clinical validation.
The clinical evidence for cramp bark presents an unusual split: the best human data supports an indication from a different tradition, using a different plant part, for a completely different condition.
What the clinical trials actually show — kidney stones, fruit extract:
An RCT from 2021 (n=86) compared V. opulus fruit extract against tamsulosin (the standard medication) for small distal ureteral stones. The fruit extract matched tamsulosin for overall stone expulsion, and significantly outperformed it on pain: 37.2% vs 65.1% needed additional analgesics (P=.017), and 11.6% vs 34.8% needed emergency visits (P=.02). For medium-sized stones (5–10mm), expulsion was 4 days faster on average [1].
A 2019 retrospective study (n=103) found the fruit extract improved expulsion rates from 66% to 82% compared to diclofenac alone — a 16 percentage point improvement — with passage about 5 days faster [2].
These are credible results. They just don’t tell you anything about the Western herbalism use case.
What the clinical trials do not show — dysmenorrhea and cramps:
No RCTs have been published for cramp bark’s primary traditional indication. A registered trial (NCT02467543) tested a homeopathic 3X dilution (1:1000) — not a botanical extract — and has not produced a peer-reviewed publication. The clinical evidence gap for dysmenorrhea is real.
Why the traditional mechanism is still credible:
The honest position: For kidney stones (gilaburu, fruit, Turkish tradition) — there’s solid human data. For dysmenorrhea and muscle cramps (bark, Western tradition) — you’re working from centuries of convergent clinical use plus preclinical mechanism. That’s a legitimate evidence basis in herbal medicine, but it’s different from an RCT, and worth being clear about.
Critical distinction: The clinical trials used fruit for kidney stones. Western herbalism uses bark for cramps. Different plant parts, different phytochemical profiles, different indications, different evidence bases. A gilaburu capsule is not cramp bark tincture.
Cramp bark earned its common name directly from clinical practice. 19th-century North American Eclectic physicians — particularly Felter and Lloyd — documented it as one of their premier antispasmodics for uterine cramping, afterpains, and dysmenorrhea [6]. The British Herbal Pharmacopoeia (1983) formally recognized the same indications with a quality monograph establishing official standards [7].
The consistent message across all Western traditions: smooth muscle in spasm. Tight, cramping, constricting pain — uterine, intestinal, or otherwise. Not diffuse inflammatory aching. Not nerve pain. Smooth muscle that is seizing.
German phytotherapy (Weiss tradition) prescribed it at acute-onset doses specifically for dysmenorrhea: 4–8 mL tincture, three to four times daily, starting with cramp onset [6]. Higher than the standard AHP dose — consistent with acute symptom management rather than tonic use.
Eastern Europe — kalina: Known as “kalina” across Slavic traditions, V. opulus appears in Polish and Ukrainian folk songs, wedding customs, and medicine simultaneously. Bark and fruit were both used for menstrual irregularities, uterine spasms, and cardiovascular conditions. The word “kalina” carries cultural weight well beyond its medicinal use.
Turkey — gilaburu, a separate story: In Kayseri and Central Anatolia, the fruit became the stone medicine — taş düşürücü (“stone-dropping”). Gilaburu juice is sold commercially throughout Turkey today. This tradition produced the actual human clinical data. The two evidence streams — Western bark for cramps, Turkish fruit for stones — are distinct and should be treated as such.
Decide what you’re treating before choosing a preparation:
For dysmenorrhea and muscle cramps → bark preparations (Western tradition)
Tincture (1:5, 40–50% ethanol) is the most practical form. Start with 5–7 mL in a small amount of water, three times daily:
Decoction: simmer 2–3 g dried bark in 250 mL water for 10–15 minutes, strain, drink three cups daily. More work, but traditional.
For kidney stones (with small, distal ureteral stones confirmed by imaging) → fruit extract (gilaburu tradition)
The clinical trials used 1000 mg oral fruit extract three times daily. Use alongside conventional monitoring — not as a replacement for urological care.
| Preparation | Dose | Frequency |
|---|---|---|
| Tincture (1:5) — standard | 5–10 mL | 3× daily |
| Tincture — acute dysmenorrhea (Weiss) | 4–8 mL | 3–4× daily |
| Decoction | 2–4 g bark | 3× daily |
| Fluid extract (1:1) | 2–4 mL | 3× daily |
| Fruit extract (stones only) | 1000 mg | 3× daily |
Smooth muscle relaxants act faster than adaptogens or tonics. If a liquid preparation is going to help with cramping, you should notice something within 20–60 minutes. If you take full doses across 2–3 cycles of menstrual pain and notice nothing, this may not be the right herb for your cramp pattern. Some cramping is more inflammatory than spasmodic — cramp bark addresses spasm specifically.
For dysmenorrhea:
Signs it’s working:
Signs this isn’t the right herb:
For kidney stones: Self-reported stone passage is unreliable — stones can pass silently or fragment. Use imaging for confirmation and work with your urologist if following the gilaburu protocol.
Cramp bark decoction is bitter and noticeably astringent. The tannins stick to your mouth in a way that’s unmistakable. Not the most unpleasant bark preparation you’ll encounter, but not something you’d drink for pleasure.
Tincture is easier — a measured dose in a small amount of juice or water goes down quickly. The bitterness is still there, but brief.
The taste is not beside the point: the same tannins and phenolics contributing to astringency are part of the phytochemical profile. Bark capsules may miss some constituents that only extract into water or ethanol when made traditionally.
Cramp bark has a significant quality problem: no standardized extract definition exists for bark preparations.
Scopoletin and viopudial — the primary active compounds from bark — are not standardized in commercial products. Two bottles labeled “cramp bark extract” may have entirely different amounts of the compounds with demonstrated activity. The American Herbal Pharmacopoeia (2000) provides botanical identity and authentication standards (TLC/HPLC to verify you’re getting V. opulus), but therapeutic compound standardization is not commercially routine [6].
What to look for:
Avoid: Unspecified “cramp bark extract” capsules from unknown suppliers with no extraction ratio or quality documentation. The mg dose on the label is meaningless without knowing what was actually extracted.
For kidney stones specifically: Look for fruit extract labeled as “gilaburu extract” or V. opulus fruit — this is what the clinical trials used, and it has different phytochemistry from bark.
Cramp bark is among the most consistently used antispasmodic herbs in Western herbalism, recommended across British, North American, German, and Eastern European traditions for essentially the same indication — tight, spasmodic, smooth muscle cramping — for several hundred years. That’s a meaningful signal.
The evidence situation is honest: the mechanism is preclinically solid (scopoletin and viopudial are real compounds with real smooth muscle relaxant activity), but no one has run an RCT for the Western use case. The human data that exists — and it’s good data — tests a different preparation for a different indication entirely.
For dysmenorrhea and smooth muscle spasm: this is a reasonable first-line herb alongside or instead of NSAIDs, with the understanding that you’re working from traditional evidence and mechanistic plausibility, not clinical trials. The n=1 experiment is the actual test.
For small distal ureteral kidney stones: the gilaburu fruit extract data is credible, and it’s worth discussing with a urologist as part of medical expulsive therapy.
Use bark tincture for cramps. Use fruit extract for stones. Don’t confuse the two traditions or their evidence bases.
Duration: For dysmenorrhea: start 1–2 days before expected period onset; continue through heaviest 2–3 days. Acute muscle spasm: use at first onset. Expect effects within 20–60 minutes of liquid preparations if they're going to work.
What to notice:
Start with tincture at 5–7 mL three times daily. The traditional indication is specific: smooth muscle in spasm — tight, constricting cramping rather than diffuse inflammatory aching. It's not a general painkiller. The mechanism (scopoletin relaxing smooth muscle) is preclinically solid; whether it translates to your individual cramp pattern is something only direct experience can determine. For kidney stones: use fruit extract (gilaburu), not bark. The clinical data applies to fruit preparations only.
Generally considered: caution
Contraindications:
Pregnancy/Nursing: Avoid in pregnancy without professional supervision. BHP 1983 listed threatened miscarriage as an indication, but this required trained clinical oversight. No lactation safety data.
Generally well-tolerated at standard doses based on traditional use and limited clinical data. No hepatotoxicity signals in published literature — no case reports, no pyrrolizidine alkaloids in phytochemical profile. Clinical trials (n=189 total) reported no serious adverse events at 1000 mg 3× daily for up to 4 weeks. GI upset possible at high doses. No long-term controlled safety studies exist. Absence of standardization means potency varies significantly between commercial products.