Educational information, not medical advice — ask your doctor or midwife.
What is guelder rose?
Guelder rose is a shrub that grows wild across Europe, including Norway, Sweden and Finland. It is called krossved in Norwegian and Swedish, and koiranheisi in Finnish. Two parts are used: the bark and the bright red berries.
The dried bark is sold under the trade name "cramp bark". The berries are very tart. In the Nordic countries they are cooked into jam, juice and sauce.
Raw berries are harsh on the stomach. Eating a lot of them raw can cause vomiting and loose stools. Cooking makes them much easier to tolerate.
Here is the honest verdict on the evidence. Human trials are few, small and weak, and none show a clear benefit. Long use in folk medicine is not proof that it works, and it is not proof that it is safe.
How is it meant to work?
No one has shown how guelder rose works in people. The ideas below come from test-tube and animal studies only.
The bark's old reputation is as an antispasmodic (a muscle-relaxer). In test-tube work, bark extracts have relaxed strips of smooth muscle, including womb tissue. Whether this happens in a living person is not established.
The bark holds coumarins, a group of plant compounds related to some blood-thinning drugs. In lab studies, such compounds can slow clotting. This is a reason for caution, not a proven effect in people.
The berries are rich in anthocyanins, the red pigments. In test tubes these mop up free radicals (unstable molecules). An antioxidant result in a test tube does not mean a health benefit in your body.
Some lab work suggests berry juice may change how certain crystals form in urine. Researchers in Turkey have looked at this for kidney stones. The human data are early and thin.
What forms is it sold in?
Most products use either the dried bark or the fruit. Read the label to see which one you have.
Common forms: - Dried, cut bark for making a tea or decoction (a simmered brew) - Bark tincture, an alcohol extract in drops - Capsules or tablets of powdered bark - Bottled berry juice, often sweetened - Jam, cordial and sauce made from cooked berries - Frozen or dried whole berries
Food products made from cooked berries are the mildest form. Bark products are the ones linked with the cautions on this page. Strength is not standardised, so two bark tinctures can differ a lot.
Where does its reputation come from?
Guelder rose has a long place in Nordic and wider northern European folk use. The berries were picked after the first frosts, when they taste less bitter.
In Scandinavia and Finland the cooked fruit was eaten as a winter food and valued as a source of vitamin C. Folk healers also gave berry drinks for coughs and colds. The Finnish name koiranheisi, roughly "dog's viburnum", hints that the raw fruit was not thought of highly as food.
The bark had a separate reputation. Healers in northern and eastern Europe used it for cramping pain, including period pain. In the 1800s, doctors in North America took up the same idea and gave it the name cramp bark.
These records tell you what people did. They do not tell you whether it helped.
When to see a doctor
Stop using it and get medical advice if you notice any of these:
- Vomiting or diarrhoea that does not settle within a day - Blood in your vomit or stool - Unusual bruising, nosebleeds or bleeding gums - A rash, swelling of the lips or face, or trouble breathing - Dizziness or fainting
Go to an emergency department if a child has eaten a handful of raw berries and is vomiting repeatedly or seems drowsy.
See a doctor rather than self-treating if your period pain is severe, new or getting worse. The same goes for back or side pain that could be a kidney stone.
In the Nordic countries the cooked berries are an ordinary food, sold as jam and juice. In the EU and the UK, bark products are sold as food supplements, not as licensed medicines. In the United States it is a dietary supplement, and the FDA has not approved it to treat any condition.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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