The National Center for Complementary and Alternative Medicine (NCCAM; 2012) includes herbal preparations (also called botanicals), vitamins, minerals, dietary supplements or nutraceuticals, essential oils, and live microorganisms (usually bacteria) in a category of therapies entitled natural products. This group also includes the growing area of probiotics. People from even the earliest times have used herbal preparations to improve health or cure illnesses. Hildegard of Bingen, a Benedictine nun, wrote treatises in the 12th century detailing a large number of natural products such as herbs that could be used in healing (Encyclopedia of World Biography, 2004). Herbal product compounds for traditional Chinese medicine were documented in the Chinese Materia Medica as early as 400 bce (Beijing Digital Museum of Traditional Chinese Medicine, 2012).

Although the use of herbal preparations decreased in the 20th century as new medicines evolved, there has been resurgence in the public’s use of natural products. The 2007 National Health Interview Survey included questions on the use of complementary therapies (Barnes, Bloom, & Nahin, 2008). The report noted that 17.7% of those surveyed used one or more nonvitamin/nonmineral natural products. This was true for both adults and children. Commonly used products included fish oil/omega 3s (37% of adults) and echinacea (37.2% of children) (Barnes et al., 2008).