Complementary and alternative medicine (CAM for short in English) The methods and health care products that are currently not considered part of conventional medicine are called CAM. Complementary medicine is used together with conventional medicine. Alternative medicine is used instead of conventional medicine. Scientific evidence of the effectiveness of some of these treatments. But in most cases there have been no scientific studies designed to answer fundamental questions about its safety and efficacy in diseases or ailments for which they are used. Josyann Abisaab The National Center for Complementary and Alternative Medicine (NCCAM, its acronym in English), part of the National Institutes of Health (NIH, for its acronym in English) is the primary federal agency for U.S. conducts scientific research on complementary and alternative medicine.