Buy from a trusted source. Ingredients should be clearly listed, along with the manufacturer's label. Look for the batch or lot number, and the date of expiration. Also, several dietary supplement certification programs now offer stamps of approval. "They aren't a guarantee, because the FDA doesn't routinely test for purity or effectiveness," says Carol Haggans at the National Institutes of Health Office of Dietary Supplements. "But they're worth looking for."
Buy standardized herbal extracts. Standardization gives some assurance that a product consistently contains active ingredients at a set concentration. Many standardized supplements are available.
Certain people should be cautious in weighing the benefits and risks of supplements. Little is known about what botanicals might do to an unborn baby, for example. The same precautions apply to young children and older adults, whose changing bodies process substances differently than others.
Be careful mixing meds. If you're taking prescription medications or other supplements, note that substances can interact. For example, ginkgo biloba can interfere with anticoagulants, and St. John's wort may interact with HIV drugs or SSRIs. Also, stop all dietary supplements 14 days before surgery to avoid complications.
