Be Wary of Certain Words

“Standardized” “Verified” or “Certified” – Some manufacturers use those terms to describe efforts to keep ingredients potent and consistent across batches. But those words have no legal meaning and don’t guarantee quality or safety, according to the Office of Dietary Supplements (ODS) at the National Institutes of Health.

“Proprietary” – “Especially be concerned about proprietary formulas, where they don’t even tell you the amount of the specific ingredient,” Dr. Cooperman says. “It may not be a bad formula, but it’s really better if they self disclose.”

Consider Single Sources

In ConsumerLab’s tests, multivitamins and multimineral pills were more likely to fall short than single-source products, Dr. Cooperman says, simply because they’re more complex.

If getting more daily calcium and folic acid is important, for example, you may be better off taking those individually and relying on a balanced diet to supply the rest of your nutritional requirements.

Look for Independent Certification

A number of independent organizations have voluntary certification programs for supplement manufacturers. Their seal of approval on the bottle tells you that the product contains what it promises, has passed tests for certain contaminants and releases its ingredients the way it's supposed to, but not that it is safe or effective, according to ODS. Still the programs offer an extra measure of confidence for consumers. To see what these seals look like, click on the program names below:

Consumerlab.com approved quality product seal
NSF International dietary supplement certification
U.S. Pharmacopeia dietary supplement verification program
Natural Products Association TruLabel program

Test Your Tablets

Sometimes, pills don’t dissolve they way they’re supposed to in the stomach, which keeps them from being effective. If you’re concerned that your supplement isn’t breaking down properly, Dr. Cooperman suggests this low-tech test, which you can try at home. (One caveat, this experiment isn’t valid for chewable tablets or for supplements that have enteric coatings to keep them dissolving in the stomach, where they may cause irritation.)

In a heat-safe mug, warm a half-cup of vinegar to 98 degrees, which is body temperature. Dr. Cooperman says a coffee warmer or the hot plate of a coffee maker works well for this. Check the temperature with an instant read thermometer. Drop a pill in the cup and stir or swirl the vinegar occasionally without touching the tablet. You may have to move the cup on and off the hot plate to keep the temp consistent.

“Within 30 to 45 minutes, the pill should be completely disintegrated,” Dr. Cooperman says. You may still see dregs of the pill in the cup, but it should be completely broken apart.