Butterbur, or Petasites hybridus, is a type of marsh plant that’s long been used for medicinal purposes. It grows throughout Europe and in certain parts of Asia and North America. It gets its name from its large leaves that were used to wrap butter to keep it fresh in warm weather.

All parts of the butterbur plant have also been used to treat a variety of health problems. It’s still used to treat headaches, especially migraines.

Researchers say butterbur is effective in reducing the intensity and frequency of migraines.

It is estimated that 30 percent of American adults and 40 percent of children are affected by allergies. Because of its reputation for treating a number or illnesses, butterbur is now being studied as a possible treatment for allergies.

So far findings suggest that the plant may be an effective treatment for nasal allergies. Butterbur would be administered as an oil extract or in pill form.

One study found that butterbur could suppress allergic reactions in rats. In a human study, people with allergies that were given butterbur tablets for a week showed significant improvement of their allergy symptoms. After five days of treatment, the participants’ bodies contained smaller amounts of the allergy-producing substances leukotriene and histamines.

When your body comes into contact with an allergen, it releases the inflammatory chemical leukotriene. Leukotriene is what’s responsible for triggering an allergic reaction in your body.

Leukotriene (LT) inhibitors block leukotriene and prevent or relieve an allergic reaction. Butterbur seems to act as an LT receptor inhibitor, much like the drug montelukast (Singulair).

Montelukast can be used to treat nasal allergies. It can also cause severe mental health side effects, so it isn’t recommended as an allergy treatment unless there are no other suitable options.

However, researchers haven’t yet found that butterbur is useful in treating asthma or skin allergies.

Unprocessed butterbur contains chemicals called pyrrolizidine alkaloids (PAs). PAs can cause serious liver damage and other illnesses.

However, the National Institutes of Health (NIH) reports that PA-free butterbur products are safe, effective, and don’t cause side effects in most people. They should be taken by mouth in the recommended doses for 12 to 16 weeks. However, it is not known if using butterbur for a long period of time could cause problems.

Most people tolerate butterbur well, but it may cause side effects in some people. Side effects most often affect those who are allergic to plants. Because butterbur is part of the daisy family, you should avoid using it if you are allergic to plants in that family. Side effects may include:

  • allergic reactions
  • belching
  • headaches
  • itchy eyes
  • digestive problems
  • fatigue
  • sleepiness

You should always talk to your doctor before starting an alternative allergy treatment. Because butterbur could cause allergic reactions, it should only be given to children under a doctor’s supervision. It’s also important that if you use butterbur products you make sure that they are processed and labeled as PA-free.