Petadolex Fast-Acting contains pure butterbur extract to support healthy blood vessel tone in the head as well as normal blood flow in the brain. The exclusive patented process (U.S. Patent #6551626) removes toxins naturally present in butterbur making it the ONLY safe form available. . . The butterbur in Petadolex Fast-Acting has been studied in a neurological clinical trial examining short-term use for immediate support. More than 75% of participants experienced an immediate response that was reported as ''good'' or ''excellent.'' (See table on package.) On average participants experienced a 54% decrease in the duration of an occurrence.. .Other products from HerbsPro