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Product Reviews (110)

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CL Answers (333)

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Clinical Updates (68)

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Green Tea and Liver Toxicity

Green tea extract was listed as one of the most common dietary supplements linked to liver injury in a newly published guideline for diagnosing and treating drug-induced liver injury. Find out what one of the authors of the guideline had to say about the catechin content of some green tea supplements, and get our test results showing the amounts of catechins in green tea supplements in the Green Tea Supplements, Drinks and Brewable Teas Review >>   

Do Spreads Lower Heart Risk?

Buttery spreads like Smart Balance and Benecol claim to lower the risk of heart disease due to their phytosterols/stanols. These plant compounds can certainly help (by lowering cholesterol levels), but recent lawsuits challenge whether Smart Balance and Benecol provide enough sterols/stanols to claim a benefit. It turns out that one may, and one may not. Find out more and get our quality ratings of cholesterol-lowering supplements in the updated Cholesterol-Lowering Supplements Review >>

Omicron Reinfection

Find out if infection with one Omicron variant (BA.1 or BA.2) protects you from getting reinfected with the other.

Switching from Pfizer to Moderna

Find out if switching from Pfizer to Moderna or vice versa boosts antibody levels more than sticking with one brand.

Probiotics for C. difficile infection?

New guidelines recommend against probiotics for treating or preventing C. difficile infection, one cause of diarrhea in people taking antibiotics. Find out why in the What They Do section of our Probiotic Supplements Review.

Moderna vs. Pfizer: When to Choose One Over the Other

Two very different medical reports this week seem to indicate important, although subtle, differences between these two mRNA vaccines. Namely, that the Moderna vaccine has somewhat greater efficacy but, not unexpectedly, at somewhat greater risk of myocarditis in younger people. This seems to suggest that, if given a choice, Moderna may be better for older people while Pfizer may be safer for younger people.

Muscle Cramps from Lack of Vitamin

Painful muscle cramps in an older person resolved after correcting a deficiency in one of the B vitamins, according to a new report. Get the details, and learn which conditions and medications increase the risk of this deficiency, in the B Vitamin Supplements Review. Also see our Top Picks for B vitamin supplements.

Cranberry and UTIs

Two popular cranberry supplements promoted for urinary tract health were compared in a clinical study that showed one to be 4 times as effective as the other at preventing the adhesion of UTI-causing bacteria in urine. Get the details in our article about Cranberry and UTIs.

Nutrients In Jeopardy With a Plant-Based Diet?

Which nutrients are in jeopardy when one switches from animal to plant-based proteins? Find out what a recent study showed in the Concerns and Cautions section of our Protein Supplements Review. Also see our Top Picks among protein supplements.

New N95 Top Pick

We evaluated two more N95s masks, and one is a new Top Pick. Get the details in our article about Finding the Best Masks.

Also see our Top Pick among KN95 masks.


Eggs and Heart Risk

Does eating one or two eggs daily increase the risk of heart attack? Find out what recent studies suggest in the Concerns and Cautions section of our Choline Supplements Review (eggs contain choline). Also see our Top Picks among choline supplements.

Risk of Too Much B-12

It’s easy to get way more vitamin B-12 than one needs from supplements. Unfortunately, high blood levels of B-12 are being linked to higher risks of death and disease, as shown in a recent U.S. study. Get the details in the Upper Limit for B-12 section of our B Vitamin Supplements Review. Also, see our Top Pick among B-12 supplements.


Coffee and Heart Health

Drinking moderate amounts of one type of coffee, but not another, was linked to a reduced risk of heart attack and stroke in a recent analysis. Get the details in our updated article about Coffee and Health.


CPAP Humidifiers & PFAS?

Can using a CPAP humidifier increase one's exposure to potentially dangerous PFAS? Find out in our updated answer about Avoiding PFAS.


Antibody Treatment Effectiveness Against BA.2 Variant

Although two monoclonal antibody treatments (bebtelovimab and sotrovimab) appear to be effective against the Omicron variant, one may have reduced activity against the BA.2 variant.


Does Vitamin D Help Manage Weight?

If you've been reading our recent newsletters, many reports are being published about the effects of vitamin D. Here's one more: People with higher levels of vitamin D tend to put on less weight than people with lower levels. See the details in the update to the Vitamin D Supplements ReviewMore >>

Can Resveratrol Help Control Blood Sugar?

A new clinical study suggests potential benefits for people with type 2 diabetes taking one of the resveratrol products evaluated by Get the details in the latest update to's Resveratrol Supplements ReviewMore >>

A More Effective Way to Take Sterols/Stanols to Lower Cholesterol?

A new study shows that taking sterols and stanols from a softgel appears to lower cholesterol more effectively than from a tablet. Get the details, including the name of a new product like the one taken in the study, in the updated Cholesterol-Lowering Supplements Review.  More >>

Probiotic Helps with Colic

Daily use of a probiotic reduced crying time in infants by nearly half and regurgitation by more than one-third in a recent study. Probiotics have also reduced abdominal pain in older children. Based on their safety, probiotics seem worth a try for these uses. Details about the products and dosage are in the update to the Probiotics Review >> 

FDA Finds Another Generic Drug Not Equivalent

According to the FDA, a marketed generic version of the antidepressant buproprion hydrochloride XL (300 mg) is not equivalent to the brand name Wellbutrin XL and the product is being removed from the market. One year ago, another generic version of this drug was removed from the market for the same reason. first reported potential problems with these products in 2007 but the FDA was slow to take action. For details, see the updated in the Wellbutrin vs Generic Budeprion Review >>

Dark Chocolate Improves Walking in Peripheral Artery Disease

A new, small study found that people with peripheral artery disease who consumed dark chocolate with a high cocoa content were able to walk further than they normally could. Consuming milk chocolate did not have this effect. The improvement was seen shortly after consuming just one dose. For more details, including dosage, as well as our tests and comparisons of cocoa supplements and chocolate, see the update to the Cocoa Powders, Extracts and Chocolate (Sources of Flavanols) Review >>   

Prebiotic for Reducing Anxiety?

We've reported in the past that some probiotic bacteria may help reduce anxiety. A new study suggests that one type of prebiotic powder (which helps probiotic bacteria grow) has a related beneficial effect. See the update in the Probiotic Supplements Review >> 

Melatonin for Itchy Skin

Atopic dermatitis is an itchy inflammation of the skin, affecting up to 10% of adults and 30% of children. A recent study in children and adolescents with atopic dermatitis found that taking melatonin modestly reduced symptoms and, not surprisingly, reduced the time needed to fall asleep. For details about this and other uses of melatonin, as well our reviews of available melatonin supplements (including several similar to the one studied), see the Melatonin Supplements Review >>

Turmeric for Arthritis?

Curcumin (from turmeric) has shown promise in reducing the pain and inflammation of rheumatoid arthritis in several small studies, including one that was recently published. However, larger studies are needed to prove this benefit. Details are found in the "What It Does" section of the Turmeric and Curcumin Supplements Review (which includes our Top Picks among products).

CBD for Anxiety

CBD taken 90 minutes before public speaking reduced anxiety without side effects in a recent clinical trial – although it only worked at one of the three doses studied. For details, see the What It Does section of the CBD and Hemp Extract Supplements Review. (Also see our Top Picks among products.)

Avoid Quality Problems With Fish Oil

Nearly half of 17 popular fish oil supplements tested in a recently published study did not meet at least one of the quality criteria for freshness or content. Interestingly, two that passed testing were Approved by ConsumerLab, but none that failed were CL Approved. For details, see the Quality Concerns section of the Fish Oil Supplements Review. Also see our Top Picks for fish and marine oils.

Vitamin K for Bone Density?

Vitamin K (as MK-7) was given daily for one year to older men and women to see if it would improve bone mineral density. Some also received vitamin D and calcium. Find out if it helped, as well as the results of related studies, in the What It Does section of the Vitamin K Supplements Review. Also see our Top Picks among vitamin K supplements.

CoQ10 Bioavailability

CoQ10 is not well absorbed unless taken with fats or oils, such as with a meal. Bioavailability-enhanced formulations allow CoQ10 to be taken without a meal, but how good are they? We've added new information about one such formula and how it compares to taking regular CoQ10 in the Absorption and Bioavailability Enhancers section of the CoQ10 and Ubiquinol Supplements Review. Also see our Top Picks for CoQ10 and ubiquinol.

When to Eat Protein

Some evidence indicates that it is best to distribute protein across meals throughout the day to maximize protein production in muscle. A recent study suggests that there is one meal when protein intake could be higher for nearly everyone, and there is another meal when older people particularly fall short. For details see the When to Take section of the Protein Powder and Drinks Review. Also see our Top Picks for protein powders and drinks.

Has UC-II Collagen Changed?

UC-II is an undenatured collagen that may reduce knee pain. However, one of the more recent studies reported that it contained much less collagen than reported in earlier studies. Has UC-II changed? Find out in our updated answer to the question: What is UC-II and does it help joints?

Coconut Oil and Cholesterol

Coconut oil is known to raise levels of LDL ("bad") cholesterol but also increase levels of HDL ("good") cholesterol. Is one more important than the other? Find out the latest information in the Cautions and Concerns section of the Coconut Oil and MCT Oil Review. Also see our Top Picks for coconut and MCT oils.

A Food to Slow Cognitive Decline?

Adherence to a Mediterranean diet was associated with a lower risk of cognitive impairment in a major new study, but only one food within that diet -- fish -- was also linked to slower loss of cognitive function. Find out how many servings of fish had the greatest impact in the What It Does section of the Fish Oil Supplements Review. Also see if fish oil supplements help and see our Top Picks for fish oil.

Also see our Top Picks for canned tuna and salmon.

Calcium & Artery Calcification

Is there an increased risk of coronary artery calcification with the use of calcium supplements? Find out what a recent analysis showed in the Heart Attack and Stroke Risk section of the Calcium Supplements Review. Plus, learn how much calcium one needs per day and how much, if any, can come from supplements. Also see our Top Picks for calcium.

Fish Oil and Heart Disease

Many studies have assessed the potential benefits of taking fish oil supplements. Results have been conflicting, but one of the largest and longest-term studies was recently published. See what it found in the What It Does section of the Fish Oil Supplements Review. Also see our general recommendations for using fish oil for heart health and check out our Top Picks for fish oil supplements.

Vitamin D and Cancer

Several studies, including one published this month, show that sufficient levels of vitamin D in the body are associated with decreased risk of various forms of cancer. What's the best level? See "Cancer" in the What It Does section of the Vitamin D Supplements Review >>

Too Much Folate & Nerve Damage

One quarter of American men and women have a gene variation which puts them at higher risk of nerve damage if consuming too much of folate (vitamin B-9) daily, according to a new study. Considering that most older Americans consume more than this amount (largely due to excessive supplement use) this should be a warning to many. For more details, see the "Folate" section of the B Vitamins Review >>

Adding Vitamin D to Statin Treatment

A recent study among people taking statin medication for high cholesterol showed significant improvements in cholesterol levels when daily vitamin D was added as treatment. Improvements were greatest among those who began with lower blood levels of vitamin D. More details, along with our reviews of products similar to the one used in this study, are found in the Vitamin D Supplements Review >>

Niagen Form of Niacin May Cause Flushing

Niacin is known to cause flushing (redness) and skin tingling at moderate doses. Other forms of niacin are said cause less flushing. One of these is Niagen. However, results of a recently published study suggest that it can cause flushing and "hotness" after just a single dose. More details are in the "Niacin" section of the B Vitamin Supplements Review >>

Side-Effect With B-12

Certain formulations of vitamin B-12 contain additional ingredients that can cause diarrhea and bloating in some people — particularly if taking more than one pill. An apparent case of this was reported to us this week. To help you avoid this, read the details in the "What CL Found" section of the B Vitamin Supplements Review (which includes our tests of products) >>

What Iron Supplements Can and Cannot Do

Iron supplements can reduce fatigue in younger women and even improve learning in adolescent girls. If you give blood, taking iron reduces your time to recover by more than one month. However, a recent study found little benefit in giving iron to heart failure patients low in iron. Researchers have an idea why. For details about the uses of iron, see the "What It Does" section of the Iron Supplements Review, which includes our tests and comparisons of popular iron supplements.

Adequate Vitamin D Reduces Frequent Respiratory Infections

A study in people with frequent respiratory infections found that taking vitamin D for one year resulted in fewer infections than taking placebo. In contrast, a similar study did not find a benefit. Why the difference? Find out in the Vitamin D Supplements Review >>

Is Ester-C Better?

One of the forms of vitamin C in supplements is Ester-C. In addition to being non-acidic, a recent study suggests another possible benefit over regular vitamin C (ascorbic acid). Get more information about this and other forms of vitamin C in the "ConsumerTips" section of the Vitamin C Supplements Review >>

Vitamin D2 or D3?

Although both the D2 and D3 forms of vitamin D can raise blood levels of vitamin D, a new study showed one to be significantly better than the other — and there are some interesting explanations for this. Learn more in the "What to Consider When Using" section of the Vitamin D Supplements Review, which includes our Top Picks.

Magnesium Cream?

Is rubbing a cream into your skin a good way to get magnesium? We reviewed several studies of magnesium creams or sprays, including one just recently published. See what we found in the "What It Does" section of the Magnesium Supplements Review -- which includes our Top Picks among magnesium supplements.

Does Lutein Help?

Lutein is an antioxidant that helps protect the retina of the eye and can slow the progression of macular degeneration. But does taking lutein help if you already have normal macular density? Two studies have "looked" at this question (including one published this week) and, you can "see" the answer in the "What It Does" section of Vision Supplements (Lutein & Zeaxanthin) Review >>

Vitamin D and Cardiovascular Disease

Can high doses of vitamin D improve cardiovascular function? A large, one-year study in England recently sought to answer this question. Learn what the researchers discovered in the "What It Does" section of the Vitamin D Supplements Review (which includes our Top Picks for vitamin D supplements).

What Niagen Does

Niagen (nicotinamide riboside) has been promoted as an anti-aging supplement. Find out what's been shown in clinical studies, including one published recently, in the Niacin section of the B Vitamin Supplements Review.

Probiotic Concern

While probiotics are generally safe, they can cause severe illness in people with certain medical conditions. There have been many case reports, including one published this month. For details see the Concerns and Cautions section of the Probiotic Supplements Review.

Vitamin C and Prostate Cancer

Does taking vitamin C reduce the chance of developing prostate cancer? Find out what studies are showing, including one reported this month, in the What It Does section of the Vitamin C Supplements Review. (Also learn about vitamin C and cataracts and see our Top Picks for vitamin C.)

Probiotics and Weight?

Several studies, including a recent one in Brazil, suggest that probiotics can help with weight reduction or other aspects of slimming. The studies published to-date, however, have limitations. For more details, see the "What It Does" section of the Probiotics Supplements Review (which includes our tests of products) >>

Lead in Maca Powder

A woman in California who was taking maca powder daily to treat fatigue found it was also increasing the concentration of lead in her blood. More concerning is that the amount of lead in her maca was only 1/3 the lead level in one of the popular maca powders tested by Get the details, and find out which maca supplements passed or failed’s tests in the Maca Supplements Review.

Fish Oil Drug May Help

High doses of fish oil highly-concentrated in EPA and/or DHA are known to lower elevated triglycerides. But can they reduce the risk of cardiac events, such as heart attack? Preliminary results from a new study suggest that one product can — at least in certain people. Get the details in the Prescription Fish Oil vs. Supplements section of the Fish Oil Supplements Review. (Also see our Top Picks among fish oil supplements.)

Right Amount of D for Cognition

Three different doses of vitamin D were given to older women in a one-year study of cognition. Find out which dose resulted in the best performance on cognitive tests in the What It Does section of the Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

Best form of B12?

It's important for many older adults and people using medications that reduce stomach acid to take a vitamin B12 supplement. Three different forms of B12 are sold. A recent study suggests that one may be better than another. Get the details in the B12 (cobalamin) section of the B Vitamin Supplements Review >> [Also see our Top Pick for B12 supplements in the Review.]

Licorice Tea Caution

Be careful with licorice tea because it can cause serious side effects, as recently happened to a man who drank one to two cups daily. Get more details in our answer about licorice tea.

Green Tea & Stroke

Studies have found green tea consumption to be associated with a decreased risk of stroke. However, a recent study found this to be the case for only for one gender. For details, see the What It Does section of the Green Tea Review. Also see our Top Picks for green tea.

Glucosamine & Chondroitin – How They May Work

A recent study suggests that one way glucosamine and chondroitin may work is through the gut. For details, see the What It Does section of the Joint Health Supplements Review (Glucosamine, Chondroitin, MSM and Boswellia). Also see our Top Picks among products.

Many Benefits of Magnesium

An analysis of studies involving more than one million people found that rates of stroke, heart failure, type 2 diabetes, and death were lower when intakes of magnesium were higher. For details see the "What It Does" section of the Magnesium Supplements Review (which includes our tests of products) >>

CBD Cream for Pain?

People suffering peripheral neuropathy in their legs and feet applied CBD cream or placebo for one month. Did it help? Find out in the Topical CBD section of our CBD Review. Also see our Top Picks among creams, oils, and other CBD products.

Fish Oils Not Equal on Cardio Benefit

High-dose, highly-concentrated fish oil is known to lower triglycerides in people with elevated levels. One prescription product was even shown to lower the risk of cardiovascular events in such people. However, a clinical trial of another fish oil was recently stopped due to its low likelihood of providing this benefit. Learn how these products differ and how fish oil supplements compare to them in the Prescription Fish Oil vs. Supplements section of the Fish Oil Review. Also see our Top Picks for fish oil and other marine omega-3 supplements.

Fish Oil Helps in Schizophrenia

A study found that concentrated fish oil greatly reduced symptoms in more people who had recently experienced a first episode of schizophrenia than did a placebo. The greatest effect was on depressive symptoms, which is consistent with other studies which have shown fish oil to reduce depression, particularly in people who do not regularly eat fish.

This impact on depression has also been suggested as one reason why fish oil has shown some benefit in people with cognitive decline. Details about the studies and products used, including our tests and reviews of similar fish oil supplements, are found in the Fish Oil and Omega-3 Fatty Acid Supplements Review >>

Be Careful with Iodine -- Especially If You're Pregnant

Unlike over-the-counter medicines, dietary supplements are generally not required to carry warning labels, even if they contain toxic amounts of ingredients. If you don't know how much of a vitamin, mineral, or other ingredient you really need, it's easily possible to get too much. This is what seems to have happened to some pregnant women taking a widely-sold iodine supplement, according to a recent medical report. Just one tablet contained 57 times the daily iodine they needed and more than ten times the limit associated with increased risk of toxicity. Their children were born with congenital hypothyroidism, apparently due to getting too much iodine from their mothers.

Find out which product these women took in the updated Iodine section of the Multivitamin Supplements Review. You'll also find appropriate levels of other vitamins and minerals and see which products in the Review did or did not exceed tolerable intake levels of vitamins and minerals. More >>

Most Herbal Products Don't Contain Listed Herb

DNA analysis of 44 herbal products from Canada and the U.S. found that only 48% contained the herb listed on the label and one-third of these products contained contaminants or fillers not listed on the label (Newmaster, BMC Med 2013). Nine percent of products contained only rice or wheat and none of the listed herb. Many cases of herb substitution were reported, including senna (a laxative) in a product labeled as St. John's wort. Several products were contaminated with feverfew, which should not be consumed by pregnant women and may react with a variety of medications. The researchers, from the University of Guelph in Ontario, did not disclose the identities of the tested products, which were single-ingredient herbs sold as capsules, powders, or tablets. Significant challenges continue to exist for routine use of DNA analysis of herbs, but may use this technique where appropriate in the future, alongside other analytical techniques in its Product Reviews.   

Large Study Suggests Best Vitamin D Level

What's the best level of vitamin D in your body for overall health? One way to answer this question is to compare mortality rates (deaths per year) associated different levels of vitamin D. A new study did just this, reviewing information about thousands of Americans. It concluded the best levels are between 20 and 40 ng/mL, as the risk of dying is fairly similar across this range. However, a closer look at the findings suggests an even smaller range actually associated with the lowest mortality. For the details, as well as our suggestions on how to use vitamin D, and quality ratings of products, see the Vitamin D Review.  More >>

Multivitamin Reduces Cancer Risk in Some

You may have heard that a new study found reduced rates of cancer among men taking a specific daily multivitamin. But there's more to this story... Certain types of men were much more likely to benefit than others. Several multivitamins like the one studied have been tested by, and some Quality Approved products cost as little as 3 cents a day -- a very reasonable investment if it can help you! For details, see the update in the Multivitamin Supplements Review.  More >>

Recalls & Warnings (125)

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