Key Compounds
Petasites hybridus contains several compounds with bioactive properties. Two of these compounds, petasin and isopetasin, have been studied for their ability to support healthy brain blood vessel tone and circulation.

Blood vessel tone is influenced, in part, through neuralgic, vascular, and chemical factors. This includes biosynthesis of neurochemicals, changes in calcium channel regulation, and activation of pro-inflammatory mediators, resulting in both localized and systemic changes.

Laboratory research has determined the actions of the key .P. hybridus compounds. Both petasin and isopetasin support healthy vessel relaxation.  Petasin additionally provides nutritional support for the cellular activity associated with healthy blood vessel wall functioning.

Clinical Studies
The standardized butterbur extract in Petadolex  was studied in a randomized, double-blind, placebo-controlled study (with inclusion and exclusion criteria designed in compliance with standards established by the International Headache Society). A total of 60 people received either Petadolex  or placebo for   weeks. Participants were asked to keep health diaries, which were reviewed at 4 week intervals. Both objective health data and subjective feelings of wellbeing were recorded. Thirty- three individuals were randomized to the Petadolex  group and 27 to the placebo group.

Compared to placebo, Petadolex  provided significant support of healthy blood vessel tone.  Documentation of subjective feelings revealed that 77% of the participants in the Petadolex  Patented Brain Support  group felt that the product provided beneficial health support, compared to 27% of the individuals taking the placebo.

In another placebo-controlled, double-blind, randomized trial, the efficacy of Petadolex  Patented Brain Support  in the support of healthy cranial blood vessel tone was examined with a larger number of individuals. A total of 202 participants completed the study.  

Participants were blindly randomized into one of three groups: a Petadolex  150 mg per day group, Petadolex  100 mg per day group, or the placebo group. The study lasted five months; participants were assessed every four weeks.

At the conclusion of the study, both the 100 mg extract group and the 150 mg group were noted to have significant blood vessel support compared to the placebo group. However, the group receiving 150 mg reported more support than the 100 mg group.

The authors of the study concluded that 150 mg of Petadolex  per day may be an effective nutritional supplement for support of healthy brain blood vessel tone.  

Petadolex  ASAP clinical study In an open study on the benefits of immediate dosage Petadolex , a total of 16 people took 250 mg of Petadolex  ASAP  per day (when support was needed) for   weeks.

Documentation of subjective feelings revealed that 75% of the participants in the Petadolex  ASAP  group felt that the product provided beneficial health support.

Pyrrolizidine Alkaloids Research has suggested that pyrrolizidine alkaloids found in certain plants in the family of Petasites hybridus might be linked to development of cancerPetadolex  is free of pyrrolizidine alkaloids.