Tips for being a safe and informed consumer Before taking a dietary supplement, talk to your healthcare professional. They can help you decide what supplements, if any, are right for you. You can also contact the manufacturer for product information. Take it only as described on the label.
The FDA does not require dietary supplements to be tested before marketing to prove that they are safe and that they work, as is the case with prescription drugs. As a result, products may contain ingredients and contaminants that are not on the list; some products have tested positive for prescription drugs that are not on the label. One thing you can do is to make sure that the product is certified by the United States Pharmacopoeia or NSF International, which independently evaluate the ingredients in the supplements. A supplement manufacturer can send its products to USP for analysis to verify the identity, concentration, quality, and purity of their ingredients.
Look for the USP verified mark on the product.