Based on the current body of evidence, experts are recommending an extract from the herb butterbur (Petasites hybridus) to maintain head cavity comfort. In fact, clinical trials in both Germany and the United States suggest butterbur extract may support head comfort. The Effects of Petasin and Isopetasin Pre-clinical research shows that butterbur?s major active constituents, petasin and isopetasin, enhance healthy signaling in the nervous system to support a healthy inflammatory response and promote comfort, encourage muscle comfort and help relax blood vessels in the skull. These actions may be responsible for butterbur?s ability to help control head cavity comfort. Easing Head Discomfort Migra-Eeze contains butterbur root extract standardized to provide 22.5 mg of petasin with each daily dose of two softgels. Riboflavin (vitamin B2) and ginger are included based on the ability of these nutrients to exert functional changes that may also guard against cranial discomfort.