The popularity and prevalence of herbal products and dietary supplements in the US has grown steadily. Patients are increasingly using them to prevent disease, complement conventional therapies, and promote well being and health. Nurse practitioners play a critical role in discussion, communication, and education of herbal supplement use. This article provides a review of commonly used herbal supplements regarding recent evidence for efficacy, possible drug interactions, and safety considerations.
Approximately 38 million US adults use herbal and dietary supplements. In 2009, Americans spent $5.03 billion on herbs and other botanical supplements, and their sales are steadily growing. From Sam’s Club to natural food retailer Whole Foods Market, even convenience stores sell herbal supplements such as ginkgo and echinacea alongside aspirin. Patients are regularly using herbal products to self-treat medical conditions, complement conventional therapies, and maintain their overall health and well-being. Most patients receive their information about herbs and supplements from their friends, family, and the Internet but rarely from their healthcare provider.
Since the US Dietary Supplement Health and Education Act (DSHEA) became law in 1994, vitamins, minerals, and herbal supplements are presumed to be safe and freely available. However, the FDA does not regulate dietary supplements, and there are no pre-market safety or efficacy studies required. If a dietary supplement has safety issues once it is on the market, the FDA can take action against the manufacturer by issuing a warning or removing the product. In 2007, the FDA issued its final current “good manufacturing practices” (GMPs) regulations to maintain that dietary supplements are processed consistently and meet quality standards. While improvements have been made in the oversight of supplements, issues of quality and safety continue. In 2010, the US Government Accountability Office (GAO) released a report finding trace levels of lead and other contaminants (within levels accepted by the FDA and EPA) and examples of deceptive or suspect marketing claims.
Despite increasingly common usage, only one-third of patients tell their physician about their use of supplements. Physicians do not commonly ask patients about their complementary and alternative medicine (CAM) use, and patients may feel uncomfortable discussing it. But concomitant use of herbal supplements with prescription drugs or over-the-counter (OTC) medications can put patients at risk for a variety of serious drug interactions. Herbs and drugs often interact when they use the same transport or metabolic protein, commonly cytochrome P450 (CYP) enzymes, glucuronosyltransferases (UGT), and P-glycoprotein (Pgp), resulting in induction or inhibition activity. However, many
factors, including the dose, schedule, and route of administration, can affect the potential drug-botanical interaction. If the botanical and drug are administered at different times, it is less likely that a clinically relevant interaction will occur. 
Joyce K. Anastasi, PhD, DrNP, FAAN, Lac; Michelle Chang, MS, Lac; Bernadette Capili, DNSc, NP-C. Herbal Supplements: Talking With Your Patients. Journal for Nurse Practitioners. 2011;7(1):29-35.