Supplement manufacturers are not required to test their products for safety or purity. \-f end the US Food and Drug Administration (FDA) is not required to test supplements unless an adverse effect, such as heart attack or liver failure, has been reported.

Problem: About one out of four supplements contains either less—or more—than the amount of active ingredient listed on the contaminated with pesticides or heavy metals, such as lead or arsenic...or doesn't disintegrate as it should for proper absorption. Some manufacturers correct such problems when they become aware of them, but others do not.

To learn which supplements were deemed most reliable in testing, we spoke with Tod Cooperman, MD, president of, an independent evaluator of supplements.*


Supplement makers can legally exceed the tolerable upper intake levels (ULs) for vitamins and minerals—without warning consumers. The UL, set by the National Academies of Science, is the maximum daily intake of a nutrient that is likely to pose no risk for adverse effects in healthy people. Of 32 multivitamin/multiminerals recently tested by, 12 contained at least one nutrient exceeding the UL.

*The products listed here have been evaluated by Consumerlab. com. Other evaluators of supplements include the US Pharmacopeia (USP) and NSF International. Talk to your doctor before taking any nutritional supplement.

Test results: WEIL Andrew Weil, M.D. Daily Multivitamin...NOW Adam Superior Men's Multi...and Vitamin World Time Release Mega Vitamin were among the products that exceeded the UL (35 milligrams [mg] per day) for the B vitamin niacin, with one (Swanson Daily Multi- Vitamin & Mineral) containing 100 mg. These niacin amounts were listed on the product labels. Excess niacin can cause skin flushing and tingling...very high amounts can cause liver damage. (Although 1,000 mg of niacin daily may help lower cholesterol, such high-dose therapy should be taken only under a doctor's supervision.)

Reliable products include...

  • Kirkland Signature Daily Multi, with Lycopene & Lutein and Calcium.
  • Centrum Silver Specially Formulated Multivitamin/ Multimineral for Adults 50+.
  • Nutrilite Daily Multivitamin and Multimineral.


Glucosamine combined with chondroitin sulfate slows the joint deterioration and pain associated with osteoarthritis. Glucosamine helps build and repair cartilage, while chondroitin helps preserve the elasticity of cartilage. In a well-publicized study of 1,583 people with knee osteoarthritis, a combination of the supplements helped people with moderate to severe knee pain more effectively than the prescription anti-inflammatory drug celecoxib (Celebrex) or a placebo.

Some glucosamine/chondroitin combination supplements skimp on the chondroitin content, probably because it's expensive to produce (chondroitin is predominantly derived from cow cartilage). Of the 20 combination products we recently tested, six contained less chondroitin than listed on the label. Swanson Health Products Premium Brand, while claiming to contain 250 mg per dose of chondroitin sulfate, contained only 20 mg of chondroitin.

Helpful: Products that list an exact amount of "chondroitin sulfate" per dose typically are more reliable than those labeled chondroitin "complex" or "blend." In general, 1,200 mg of chondroitin sulfate and 1,500 mg of glucosamine sulfate or glucosamine hydrochloride daily are recommended for joint pain.

Reliable products include...

  • Puritan's Pride Triple Strength Glucosamine 750 & Chondroitin 600 Dietary Supplement.
  • Cosamin DS Chondroitin Sulfate Glucosamine HCI 500 mg Chondroitin Sulfate 400 mg.
  • Vitamin World Triple Strength Glucosamine 750 mg/Chondroitin 600 mg.


In clinical trials, ginkgo biloba has been shown to fight the cognitive decline associated with dementia as well as circulation problems, ringing in the ears (tinnitus), depression and asthma. These benefits have been traced to powerful antioxidants known as flavonol glycosides and terpene lactones, compounds that appear to bolster brain activity as well as dilate blood vessels.

Not all ginkgo supplements contain sufficient amounts of these antioxidants.

Of the 13 ginkgo products tested, seven failed because of inadequate amounts of active ingredients. Three of these seven also contained high levels of lead.* All of the lead-contaminated ginkgo supplements contained ginkgo leaf powder and ginkgo leaf extract.

Helpful: To avoid possible lead contamination from ginkgo leaf powder, stick with ginkgo products made only with ginkgo leaf extract. The extraction process appears to remove lead.

The typical daily dosage is 120 mg of the extract, taken in doses of 40 mg or 50 mg over the course of the day. Choose a supplement standardized to contain 24% flavonol glycosides and 6% terpene lactones—the concentrations used in most clinical trials.

Reliable products include…

  • Nature's Bounty Ginkgo Biloba (120 mg).
  • Vitamin World Ginkgo Biloba (120 mg).
  • Puritan's Pride Ginkgo Biloba (60 mg).


Studies show that antioxidants found in green tea—including epigallocatechin gallate (EGCG)—may help prevent cancers of the stomach, lung, liveq breast and colon.

*More than 0.5 micrograms per day, as determined by the state of California, the only state to require a label warning for lead contamination in supplements.

Most green teas are caffeinated, so people who are caffeine sensitive should use the tea with caution. The seven green tea supplements we tested contained varying amounts of caffeine—from 3 mg per four-capsule dose in one product to 108 mg per four-capsule dose in another. Steeped green tea contains an average of 30 mg of caffeine per eight-ounce cup. (A cup of coffee contains about 100 mg of caffeine.)

Two of the green tea supplements we tested contained extremely high lead levels—Future-biotics Premium Standardized Green Tea Extract with 4.5 mcg of lead per two-capsule daily dose...and Herbal Select Standardized Green Tea Extract with 6.6 mcg of lead per fwo-capsule daily dose. A third failed because it didn't provide the EGCG amounts listed on its label.

Caution: Recent reports have linked green tea extracts to liver damage. Some reliable products include...

  • Life Extension Mega Green Tea Extract (725 mg per capsule), 2 mg of caffeine (one capsule).
  • Nature's Bounty Green Tea Extract (315 mg per capsule), 108 mg of caffeine (four capsules).
  • Pharmanex Tegreen 97 (250 mg per capsule), 0.75 to 3 mg of caffeine (one to four capsules).

Helpful: Given the high lead content and risks for liver damage, it may be safer to drink green tea. The amount of lead contained in one cup is likely to be lower than that found in a concentrated supplement. The cancer-fighting potency of decaffeinated green tea has not been tested in large-scale studies.

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