Supplements that claim to improve mental focus and memory may contain unapproved pharmaceutical drugs and in potentially dangerous combinations and doses, according to a new study published in the September 23, 2020, online issue issue of Neurology Clinical Practice, an official journal of the American Academy of Neurology. Researchers found five such drugs not approved in the United States in the supplements they examined. The supplements are sometimes called “nootropics,” “smart drugs” or “cognitive enhancers.”