Making Sure Supplements Measure Up

One problem—certainly not the only problem—with buying dietary supplements such as glucosamine, SAM-e, ginkgo biloba, ginseng, and so forth is that you don't know what you're getting. Does the bottle contain what the label says? In the amounts specified? What does "standardized" mean on a label? When what's in question is an herb, little is known about which constituents of each plant are the important ones. Even if you do know, the amount of the active ingredients can vary from plant to plant. In the case of chemicals like SAM-e or glucosamine, the active ingredient is known, but there is no "standardized" method for measuring it. Moreover, nobody has any idea how much SAM-e or ginkgo, for instance, it takes to produce results.

Enter ConsumerLab.com, a new testing organization with a website and a "seal of approval" that manufacturers can use if they measure up. It was founded by a physician and former natural-products chemist from the FDA, and has advisors from the American Botanical Council and other reputable organizations. Funded by private investors rather than the supplements industry, it purchases products for testing from a selection of the top-selling brands. It tests for identity and potency—not effectiveness. (That is, does the product contain what the label claims in the amounts listed? Is it truly ginseng or ginkgo, or something else? But not "does it work?") Sometimes it also tests for impurities. If a product flunks, the manufacturer can reformulate it and pay $2,500 to have it retested. Only products that pass are listed on the ConsumerLab website—not the failures. For a fee, marketers of products that pass can carry the ConsumerLab seal of approval on their packages.

Even the preliminary efforts of ConsumerLab.com show that people who buy nutritional supplements are often throwing their money away. Examples of recent findings:

• Only three out of four ginkgo biloba products tested contained ginkgo biloba in the specified amount. This herb is supposed to improve memory, among other things.

• Of 27 brands of saw palmetto, which is sold for treating symptoms of prostate enlargement, only 17 contained saw palmetto in the amounts claimed.

• Of 26 vitamin C pills, four didn't pass. Of these four, one wouldn't dissolve, and the others had less C than claimed.

Why these tests don't go far enough

Only one sample (at most two) from each brand selected is tested. This, alas, is meaningless. Herbal products vary widely, simply because of the nature of the plants and the processing. One batch of saw palmetto capsules, for instance, may differ greatly from another, even though they both come from the same processor. Tests for vitamins and minerals are more meaningful, since only one substance is involved. Even there, one sample doesn't prove much. The next batch might contain less or more.

Second, there are no tests for bioavailability of herbal supplements—that is, whether the substance will be absorbed and actually utilized by the body. Thus, ConsumerLab.com cannot test for this. And it's important.

Making supplements measure up

You have no guarantee that your supplement contains exactly what the label says. However, the chemistry of vitamins and minerals is well understood, compared to that of herbs.

It is advisable to look for "USP" on the label of vitamins and minerals. This means that the product meets the standards of the U.S. Pharmacopeia, including one for disintegration, and has been tested under controlled laboratory conditions. Generic or store-brand vitamins are more often labeled USP and are cheaper anyway. Of course, this isn't as simple as it sounds. Most brand-names are not labeled USP—but that doesn't mean they aren't up to its standards.

However, when it comes to buying herbal products like ginkgo or supplements like glucosamine, SAM-e, or mela-tonin, you're entirely on your own. Here's what consumers need and can legitimately demand from the FDA and from the companies enriching themselves in the supplements game:

• Standards of identity that ensure quality and purity; assurance that products don't vary from batch to batch.

• Herbs sold under their official Latin name, as well as their common name, with lists of scientifically established uses for each herb.

• Proof of "equivalence"—that is, a given dose of a product must contain a certain amount of key ingredients in order to produce a known effect.

• Proof that products actually will be absorbed and utilized by the body.

• Assurance that the substance is nontoxic, along with lists of any potential side effects and interactions with drugs.

Reference Source 98,99