Butterbur (Petasites hybridus) is a shrub native to Europe and temperate parts of Asia. Extracts from the leaves and roots of the butterbur plant have been used as medicine for many centuries. For the health benefits of butterbur, the plant was also introduced to North America. Today, you can find it in many parts of the US along rivers, streams and in marshy areas.

In the Middle Ages, the plant was used to help with the plague and fever. Traditional uses also included wounds, snakebites, coughs, and asthma. But Butterbur extracts were also used for allergies, upset stomachs, urinary tract pain, and muscle spasms.

Nowadays, the plant is best known as a treatment for hay fever (allergic rhinitis) and to prevent migraines. Butterbur extract is mostly available in capsule form.

You can also find the medicinal plants in some gardens where their large leaves create a dense ground cover.

Petasites japonicusis is called bog rhubarb, fuki, or giant butterbur for its enormous leaves. It has been used in cooking and traditional Chinese medicine.

For its clusters of white blooms, Petasites albus is known as white butterbur. 

Petasites fragrans has tiny fragrant mauve-pink flowers that start blooming in winter and provide insects with nectar. However, like all Petasites, the plants spread quickly by their underground stems and are difficult to contain.

Butterbur plants are flowering perennials. Their flowers appear in early spring before the leaves and can often last into May. They form large, heart-shaped leaves that are smooth on the surface but hairy below.

P. hybridus can grow up to 90-120 cm tall stems that carry leaves that are up to 60 cm in diameter. The flowers are pink to purple and clustered in dense spikes. Male and female flowers are found on separate plants.

The plants readily propagate by creeping underground stems called rhizomes. 

The common name butterbur is supposed to come from the past use of the large leaves. They were used to wrap butter for storage.

The scientific name Petasites is thought to come from the Greek word petasos. It means a broad-brimmed hat and refers to the size and shape of the leaves. 

Butterbur as a medicinal plant

Butterbur’s health benefits have been known for hundreds of years. Butterbur root extracts and extracts from its leaves have relieving effects on muscle spasms and pain. This explains the plant’s long-standing usage for respiratory conditions, headaches, and cramps in the urinary and digestive tract.

Current research suggests that butterbur is effective in the treatment of migraines and might help with allergic rhinitis.

Two RCT clinical trials tested the efficacy of the standardized butterbur extract (Petadolex) as a treatment for migraines. They found that it significantly reduced the number of migraine attacks compared to a placebo.

The studies reported only a few side effects of butterbur. The most common Petadolex butterbur side effects involved GI complaints, such as burping.

However, the plant naturally contains chemicals called pyrrolizidine alkaloids or PAs. PAs are harmful to humans and animals and can damage the liver. Therefore, you should never use fresh or dried plants yourself.

The extract used in butterbur products must be processed and purified to remove all traces of PAs. When using butterbur for migraines or other conditions, it is very important to verify that the butterbur extract is PA-free. Only butterbur products certified as PA-free should be considered for use.

Butterbur, as well as magnesium citrate, riboflavin, and coenzyme Q10, are recommended by the Canadian Headache Society for migraine prevention. They point out that these products are well tolerated, but also that only PA-free butterbur products should be used. 

Several studies have safely used Petadolex, a PA-free butterbur product for migraine, for up to 16 weeks. These include a few studies of children and adolescents. The typical butterbur dosage for migraines used in the studies was 100-150 mg per day taken in 2-3 separate doses.

Benefits of butterbur supplements include:

• anti-inflammatory (helps with inflammations)
• antispasmodic (relieves spasms)
• vasorelaxant (relaxes blood vessels) effects.

Current uses of butterbur extract include hay fever, urinary tract symptoms, painful menstruation, and respiratory and digestive conditions. Most butterbur products are available in softgel form.

The Canadian Headache Society recommends butterbur for migraine prevention.

How much butterbur for migraine prevention?

In their guideline, the Canadian Headache Society recommends taking 75 mg of butterbur twice daily. They also recommend butterbur products with standardized extracts that contain a minimum of 15% of petasins, the active compounds.

It is known that inflammation and ion channels are involved in the formation of migraine attacks. However, the exact mode of action of the petasins is not known yet.

What makes Butterbur different?

Its preventative use is undoubtedly one of the main butterbur benefits and side effects are usually uncommon and mild.

However, since the plant also contains certain harmful compounds, you should only use products certified as PA-free.

Cautions and drug interactions

PA-free butterbur is generally well tolerated. However, some people might experience some mild side effects. These include belching, upset stomach, diarrhea, headache, fatigue, and itchy eyes. 

Butterbur can cause allergic reactions if you are sensitive to plants of the daisy family, such as ragweed, chrysanthemums, or marigolds. In this case, discontinue use.

Butterbur products should not be used during pregnancy or while breastfeeding as there are no safety data available. 

Butterbur is also not suitable for people with hepatitis, any liver disease, or chronic alcohol abuse. Stop using and see your doctor if you develop symptoms of liver trouble. These include yellowing of eyes or skin, stomach pain, dark urine, sweating, nausea, unusual tiredness, or loss of appetite.  

You should also talk to your doctor if the treated condition persists or worsens.  

For long-term use of butterbur beyond 4 months seek medical advice from your doctor. However, it is always recommended to talk to your healthcare practitioner before starting any herbal or other remedies.

Also, make sure to look for a trusted brand to find the best butterbur for migraines or other conditions. 

Pascoe products that contain Butterbur: