Multi-Ingredient, Caffeine-Containing Dietary Supplements: History, Efficacy, And Safety

The objective of this presentation is to review the history, efficacy, and safety of caffeine-containing dietary supplements in the United States and Canada. PubMed and Web of Science databases (1980 – 2014) were searched for articles related to the pharmacology, toxicology, and efficacy of caffeine-containing dietary supplements with an emphasis on Ephedra-containing supplements, Ephedra-free supplements, energy drinks or shots. Among the first and most successful dietary supplements to be marketed in the U.S. and Canada were those containing Ephedra-combinations of ephedrine alkaloids, caffeine, and other phytochemicals. A decade after their inception, serious safety concerns prompted removal of Ephedra supplements from the U.S. and Canadian markets. Ephedra-free products, however, quickly filled this void. Ephedra-free supplements typically contain multiple caffeine sources in conjunction with other botanical extracts whose purposes can oftentimes be puzzling and their pharmacology difficult to predict. Ingestion of these products in the form of tablets, capsules or other solid dosage forms as either weight loss aids, exercise performance enhancers, or “energy boosters” have once again brought their safety and efficacy into question. In addition to Ephedra-free solid dosage forms, caffeine-containing energy drinks and/or shots have gained a foothold in the world market along with concerns for their safety. This presentation addresses some of the pharmacological and pharmaceutical issues that distinguish caffeine-containing dietary supplement formulations from traditional caffeine-containing beverages. Such distinctions may account for the growing safety concerns affiliated with these products.