HeadOn

. The three "active ingredients" are iris versicolor 12× (a toxic flower), white bryony 12× (a type of toxic vine), and potassium dichromate 6× (a known carcinogen). The "×" notation indicates that the three chemicals have been diluted to 1 part per trillion, 1 part per trillion, and 1 part per million respectively. This amount of dilution is so great that the product has been described as a placebo; with skeptic James Randi calling it a "major medical swindle". The formula for the Extra Strength version of the product is the same as the Migraine except that it excludes the iris versicolor.

Seymour Diamond, director of the Diamond Headache Clinic in Chicago and the inpatient headache unit at St. Joseph Hospital, was quoted as saying "I see nothing in this product that has any validity whatsoever." Consumer Reports states that no clinical-trial data involving HeadOn have been presented, and that "any apparent efficacy may be the result of the placebo effect."