David Rakel MD, FAAFP

Concerns are growing regarding the incidence of hepatotoxicity from herbal and dietary supplements. To put this into perspective, most liver injury occurs in individuals taking supplements for bodybuilding. This population often uses products to excess, and the products may be contaminated with anabolic steroids. In fact, generally the combination of contaminants and excessive dosing is associated with liver injury. Because the FDA does not regulate these products, the buyer and prescriber must beware.

When recommending more dependable vitamin and mineral products, I direct my patients to the popular chain brands. A Walmart brand generally has good quality standards because, if an independent company tests one of its product and finds that it is of poor quality, the retailer has more to lose in sales of non-supplement products. One of these independent testing labs is Consumer Labs. Consumer Labs tests over-the-counter products for quality and publishes a list of products that meet its standards. The supplement company has to provide financial support to be included in the review. Consumers must pay a membership fee to obtain the information. Although this method is not ideal in regard to removing bias, it is a start.

Recommendations are more complicated for herbal products because many factors can influence quality, including how the plant was grown, the type of soil it was grown in, when it was harvested, and what part of the plant was used (aerial, stem, leaf, root, or rhizome). At the very least, the label should contain the FDA “Good Manufacturing Practices” (GMP), which indicate standardized purity, strength, and potency of the supplement. What is on indicated on the label is what is in the pill and verifies that the supplement was made in a facility that uses good quality manufacturing practices. The National Institutes of Health LiverTox website provides a useful review of herbal products that have been found to be associated with liver toxicity.