Only MigreLief from Quantum contains Puracol???, a specially sourced whole herb feverfew with all of its naturally occurring elements intact and a high-parthenolide content. Feverfew has been safely used for centuries in Europe by migraine sufferers. Puracol Feverfew is a combination of a proprietary Feverfew extract PLUS a proprietary source of the whole herb. This combination assures a broad and concentrated range of the active ingredients which may be missing or too low in other products. Puracol??? Feverfew is a trademarked brand of the herb Feverfew.