Butterbur (Petasites hybridus) has a lot of health benefits, especially for treating migraines and respiratory allergies. However, there are also some health concerns about butterbur supplements because the plant contains pyrrolizidine alkaloids.
Here’s what you should know about butterbur supplements without pyrrolizidine alkaloids and the best choices.
Quick Picks:
- Best Overall: Linpharma Petadolex 75mg
- Best Budget Pick: Nusa Pure Butterbur Extract 100mg
Is Butterbur Safe?
Butterbur contains pyrrolizidine alkaloids (PAs), a chemical in plants which has several known health risks. Some butterbur supplements are made with a process that removes pyrrolizidine alkaloids. PA-free butterbur supplements are generally regarded as safe. The main side effect is burping. GI issues such as diarrhea can also occur.
However, more long-term research needs to be done on whether PA-free butterbur supplements are actually safe. Because of this, butterbur is not recommended for children, pregnant and breastfeeding women, or people with kidney or liver disease. (1)
What Are Pyrrolizidine Alkaloids?
Pyrrolizidine alkaloids are a natural toxin which plants make to defend themselves against herbivores. They are not toxin by themselves. However, when PAs reach the liver, they interact with enzymes. The enzymes then become highly reactive which may cause DNA changes.
Chronic exposure to PAs may lead to liver cancer. Because of this, the WHO classifies them as group II hepatocarcinogens. PAs are also linked to some other diseases, such as liver disease and hypertension.
Butterbur isn’t the only plant with PAs. Over 6,000 plants contain significant amounts of pyrrolizidine alkaloids – including black and green tea and marshmallow root. Even honey can contain high amounts of PAs if the bees harvested plants containing it. (2, 3, 4, 5, 6, 7, 8)
Safe Levels of Pyrrolizidine Alkaloids
For healthy adults, the European Food Safety Authority (EFSA) has set a threshold level of 7 nanograms (0.007 micrograms) of pyrrolizidine alkaloids per kilogram of bodyweight per day. Many people, especially regular tea drinkers, consume much higher levels of PA per day than this. (9, 10, 11)
How Much Pyrrolizidine Alkaloids Does Butterbur Contain?
Pyrrolizidine alkaloids are mostly found in the stalks and roots of butterbur. Leaf buds, leaf blades and petioles (thin leaf stem) have virtually no pyrrolizidine alkaloids. Some butterbur supplements will only use these parts to create a PA-free supplement. However, most butterbur supplements do contain PAs.
One study found that butterbur supplements contained between 0.1 and 4.48 micrograms per capsule. This is far above the EFSA upper daily limits. (12)
How Butterbur without PAs Is Made
Butterbur supplements without pyrrolizidine alkaloids are generally made from a process called supercritical CO2 extraction. The method uses carbon dioxide as a solvent to extract the healthy compounds in butterbur while leaving the toxic PAs behind. (13, 14)
Supercritical CO2 extraction is completely safe and reduces PA levels in butterbur to undetectable levels. However, the process is requires special machines so butterbur supplements made this way tend to be very expensive.
*Supercritical CO2 is also often used to extract THC from marijuana. It’s a pretty cool process. If you are into science, you can read about it here.
Third Party Testing Is Important!
Supplements are very loosely regulated. Makers aren’t required to use standardized manufacturing processes or even test their products. Because of this, claims on supplement labels aren’t always accurate. For example, one study of 21 butterbur supplements, 6 of the supplements contained absolutely no active ingredient.
This just goes to show how important 3rd party testing is. Good supplement brands will share test results upon request (tests are done for each batch, so you have to request the latest tests). They will also be clear about the methods used to remove PAs from their products.
