complémentaire santé is medicine or treatments that are not considered part of mainstream medical care, such as acupuncture to help manage side effects of cancer treatment. It’s important to note that complementary therapies should be used in conjunction with a physician-prescribed regimen, not as a replacement for it.

Many complementary practitioners believe that illness results from disturbances at multiple levels—physical, emotional, psychological, and spiritual—and that the body has an inherent ability to heal itself if given the right conditions. They use a wide range of techniques to support this healing process, including herbal prescriptions, dietary or lifestyle recommendations, physical therapy, and breathing or meditation exercises.

According to CDC’s National Health Statistics Reports, use of complementary approaches has increased in recent years. The most popular are nonvitamin, nonmineral dietary supplements; practitioner-based chiropractic or osteopathic manipulation; yoga with deep breathing or meditation; and massage therapy.

Some complementary approaches have a strong basis in science—for example, acupuncture and reiki are based on measurable physiological responses to energy work. However, much of the information about complementary therapies is anecdotal and has not been scientifically tested. Many of these practices may interact with conventional medications (prescription and over-the-counter) or dietary supplements.

The National Center for Complementary and Integrative Health (NCCIH) is a United States government agency that explores complementary and alternative health practices. Its mission is to define, through rigorous scientific investigation, the usefulness and safety of these approaches. Visit NCCIH’s Facts-at-a-Glance and Mission pages to learn more.