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CL Answer

Do any supplements help prevent or improve cataracts?

Find out which supplements may help with cataracts, including selenium and vitamins A, B1, B3, C, and E.

Doctor Shining Light for Patient Eye Exam

CL Answer

Do vitamin C supplements help prevent cataracts?

Learn more about the link between vitamin C and cataracts, based on clinical evidence.

Does Vitamin C Prevent Cataracts? -- bottle of vitamin C

CL Answer

Can castor oil eye drops improve or dissolve cataracts? Is castor oil or tea tree oil helpful for other eye conditions such as blepharitis or dry eye?

Can castor oil eye drops help cataracts or for other conditions such as blepharitis? Find out if castor oil eye drops are safe to use, and if they help for other conditions.'s answer explains.

Castor Oil for Cataracts? -- bottle of castor oil and dropper

Product Review

Vitamin C Supplements Review

Find the Best Vitamin C Supplements

Vitamin C Review 2023

CL Answer

Does ergothioneine help prevent age-related problems such as impaired cognition, Alzheimer’s disease, Parkinson’s disease or cataract, and is it safe?

Learn about ergothioneine and its potential use for cognitive impairment, dementia, Alzheimer's disease, Parkinson's disease, cataract, or kidney disease, as well as its safety and cost of supplements containing this ingredient.

Various types of mushrooms that contain ergothioneine in a wooden bowl on a wooden countertop

CL Answer

Can supplements, natural eye drops, or lifestyle modifications improve symptoms of dry eye?

Can supplements such as fish oil, flaxseed oil or curcumin (from turmeric) help treat dry eyes? Find out, including formulas and doses that have shown benefit. Also, learn if drinking more water or using eye drops containing castor oil, N-acetylcarnosine or aloe can help with dry eye.

Older man with dry eye rubbing his eyes while holding his glasses

Clinical Update


Can Vitamin E and/or Selenium Help Prevent Cataracts?

A study in older men in the U.S. found that taking large daily doses of vitamin E and/or selenium did not significantly reduce the risk of developing cataracts. But could the dose have been too high to be helpful? Other research has shown that "less is more" when it comes to antioxidant supplementation for cataracts. For more information, see the updates to the Vitamin E Supplements Review and the Selenium Supplements Review >> 

CL Answer

What are the health benefits of palmitoylethanolamide (PEA), and is it safe?

Palmitoylethanolamide (PEA) is commonly promoted for its anti-inflammatory and pain-relieving effects. Find out if it works.

Woman holding her wrist due to joint pain

CL Answer

Are L-carnosine supplements helpful and safe?

Learn about the potential health benefits of L-carnosine, as well as possible safety concerns, drug interactions and cost.

Capsules with white powder and spoon holding white powder on white background

CL Answer

What are CoQ10 side effects?

CoQ10 side effects, such as nausea, headache, and insomnia, and how you can reduce the occurrence of CoQ10 side effects.'s answer explains.

CoQ10 2024

CL Answer

Do any supplements help prevent or reduce eye floaters?

Find out eye floaters (vitreous floaters) be treated with supplements like vitamin C, lutein, ginkgo, milk thistle, collagen or hyaluronic acid, or with products such as VitreousHealth.

How to Reduce Eye Floaters With Vitamins & Supplements -- Close-up of an eye

Clinical Update


Melatonin and Cataracts

Do you have cataracts (clouded lenses of the eye)? A recent study suggests that having them removed and replaced with a certain type of intraocular lens may increase natural melatonin production. For details, see the ConsumerTips section of the new Melatonin Supplements Review. Also see our Top Picks among melatonin supplements.

Clinical Update


Multivitamin Lowers Cataract Risk

A large, long-term study using a low-dose multivitamin found that it reduced the risk of developing cataract (a clouding of the lens of the eye) by 9% compared to placebo. Interestingly, the reduced risk of cataract was negated when a separate vitamin C supplement was also taken. For details about the study and dosage, as well as our tests and comparison of multivitamins, see the updated Multivitamin and Multimineral Supplements Review.   

CL Answer

Could taking vitamin C (500 mg), CoQ10, grape seed extract, fish oil, vitamin D3/calcium/magnesium/zinc interfere with taking beta-sitosterol with dinner?

Learn about drug interactions & proper dosages for supplements such as CoQ10, vitamin D & C, fish oil, magnesium, zinc and grape seed extract.

Doctor Holding Handful of Fish Oil

CL Answer

Do glutathione supplements work to prevent aging or for other conditions?

Do glutathione supplements help with aging or other conditions such as cancer and diabetes?

Spoon filled with glutathione supplement capsules and held over a white plate

CL Answer

Which vitamins and minerals should someone over 70 take?

Find out which vitamin and mineral supplements men and women age 70 and older should take, recommended intakes for vitamin D, B6, B12, iron, plus multis, vision supplements, protein and more.

Vitamins and Minerals for People Age 70 or Older

Clinical Update


High-Dose B Vitamins & Cataract Risk

Taking high doses of B vitamins, including B vitamin complexes, folic acid and B6, was associated with a higher risk of age-related cataracts among middle-aged men and women, according to a new study. For details, see the "ConsumerTips" section of the B Vitamin Supplements Review >>

CL Answer

I've been taking a Daily Advantage multi but am now concerned by the very high % DV for vitamin C (833% DV), niacin (325% DV), and B vitamins (over 1,000% DV for several). What do you think?

Learn about the safety of taking multivitamins containing far more than Daily Values, including upper and lower limits for nutrients.

CL Answer

What are the health benefits of amla and is it safe?

Learn about amla (Indian gooseberry), including its potential health benefits and possible safety concerns.

Amla supplement capsules being poured onto a wooden table with amla fruit in the background

CL Answer

Are light boxes effective for preventing and treating seasonal affective disorder (SAD), also known as "winter depression," or circadian rhythm disorders such as jet lag? Which light boxes are best?

Learn about the benefits and safety of light boxes (including who is most likely to benefit), how to use these devices, which commercially available products appear to meet the technical requirements, and who should not use light boxes.

Man reading a book while sitting in front of a light box

Clinical Update


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.)

Clinical Update


Can-C Eye Drops for Dry Eye?

A product called Can-C Eye Drops has been promoted for improving dry eye as well as reducing the risk of cataracts. Does the evidence support this? Find in our updated CL Answer about supplements for dry eye.

Clinical Update


Castor Oil Eye Drops

Are castor oil eye drops helpful for dry eye, blepharitis, or cataracts, and are they safe? Find out in our article about castor oil eye drops.

Product Review

Melatonin Supplements Review

Trouble Sleeping? See CL's Tests of Melatonin Supplements and Top Picks.

Melatonin Review 2024

CL Answer

Are antioxidant supplements good or bad for you?

Learn more about whether antioxidants like astaxanthin, beta-carotene, coenzyme Q10, curcumin, resveratrol, selenium, vitamin A, vitamin C and vitamin E are safe and if they help prevent chronic diseases.

Can Antioxidants Cause You to Die Sooner? -- antioxidant supplements and carrots

Product Review

Selenium Supplements Review

Choose the Best Selenium Supplement. Find Out If You Need Selenium and Which Supplement Is Our Top Pick.

Selenium Supplements Reviewed by

CL Answer

Is it possible to take too much vitamin C?

Find out the daily value of vitamin C, along with possible side effects of excessive vitamin C intake. ConsumerLab explores the topic of proper vitamin C supplement usage, and why taking too much can be harmful.

Bottles of vitamin C pills

Product Review

Vision Supplements Review (with Lutein, Zeaxanthin & AREDS2 Formulas)

Find the Best Vision Supplement Based Our Tests

Product Review

Zinc Supplements and Lozenges Review

Find the Best Zinc Supplements and Lozenges. Have a Cold? See CL's Top Picks Among Zinc Supplements and Lozenges.

Zinc Supplements and Lozenges Reviewed by

Product Review

Vitamin E Supplements Review

Find the Best Vitamin E Supplement. Tests and Reviews of Popular Vitamin E Supplements & CL's Top Picks.

Vitamin E Supplements, Cream, and Oil Tested by

Recalls & Warnings

November 09, 2023

Zazzee Naturals Warned for MSM Eye Drop Claims

On October 30, 2023, the FDA issued a Warning Letter to Dexterity Health, LLC DBA Zazzee Naturals following review of the company’s Amazon storefront, which found statements about the company’s Liquid MSM Drops to be drug claims.

Recalls & Warnings

September 14, 2023

FDA Warns CVS, Walgreens, Similasan & Others for Eye Drop Violations

On September 11, 2023, the FDA issued Warning Letters to the following eight sellers of homeopathic and other types of eye drops regarding the products noted in italics due to a variety of violations of FDA regulations, most notably that they were marked with claims suggesting that they could cure, ...

Recalls & Warnings

November 29, 2023

Dr. Berne’s Whole Health Products Warned for Contaminated Eye Drop Products, Drug Claims

On November 22, 2023, the FDA issued a Warning Letter to Dr. Berne’s Whole Health Products following review of the company’s website, which found statements about the company’s Dr. Berne’s MSM Eye Drops 5%, Dr. Berne’s MSM Eye Drops 15%, and Dr.

Product Review

B Vitamin Supplements Review (B Complexes, B6, B12, Biotin, Folate, Niacin, Riboflavin & More)

See Which B Vitamins Are ConsumerLab's Top Picks!

Review of B Vitamin Supplements

CL Answer

Do any supplements help with COVID-19? Do supplements like vitamin D, zinc, vitamin C, or herbals work?

Find out if natural remedies & supplements for coronavirus such as zinc, vitamin C, garlic, or elderberry help to prevent or treat COVID-19.

Supplements for Coronavirus (COVID-19)? -- mask and pills

Recalls & Warnings

February 17, 2022

Seller of L-Theanine, Lutein, Noopept and More Warned for Drug Claims

On February 4, 2022, the FDA issued a warning letter to Crystal Clear Supplements following a review of the company’s website and social media which found statements about Tianeptine Sodium Powder, Tianeptine Sulfate Powder, PEA Capsules, Phenibut Capsules, Synephrine Powder, Noopept ...

News Release

December 13, 2023

Best Vitamin C Supplements? ConsumerLab Selects Its Top Picks

White Plains, New York, December 13, 2023 —  It’s officially cold season in the U.S., a time when many people may turn to vitamin C supplements to help “boost” their immune system and ward off colds.

Recalls & Warnings

August 28, 2023

Dr. Berne’s MSM and Castor Oil Eye Drops Recalled Due to Bacterial and Fungal Contamination

On August 26, 2023, Dr. Berne’s Whole Health Products issued a recall of all lots of its MSM DROPS 5%, 15% Solution, Dr. Berne’s Organic Castor Oil Eye Drops and Dr. Berne’s MSM MIST 15% Solution due to the risk of bacterial and fungal contamination.

Recalls & Warnings

June 12, 2023

Children's Liquid Vitamin Supplement Recalled

On June 7, 2023, Procaps S.A. de C.V. issued a voluntary recall of various lots of Laboratorios Lopez’s Bacaolinita 8 fl. oz children's liquid vitamin supplement because it contains undeclared PEG-40 hydrogenated castor oil.

CL Answer

Do any supplements or foods help prevent sunburn or skin damage from sun exposure? Can any increase your risk of sun-related skin damage?

Find out which supplements may help protect from sunburn and sun-related skin damage, including beta-carotene, vitamins A and C, and cocoa.

Dermatologist examining the skin on the back of an older woman for signs of sun damage or skin cancer

CL Answer

Do any supplements help for flu?

Which supplements may help prevent or reduce symptoms of colds or the flu, including vitamin D, ginseng, NAC, and elderberry.

Supplements for Flu -- women with the flu sitting on couch with tissues, thermometer, warm drink

News Release

June 06, 2020

Best Vitamin C Supplements Revealed by ConsumerLab

White Plains, New York, June 6, 2020 — Due to its role in maintaining immune system health, vitamin C has been promoted to help prevent and treat COVID-19, as well as other viral infections such as colds.

News Release

March 15, 2017 Reveals Best and Worst Vitamin C Supplements -- 20% Fail Tests of Quality

White Plains, New York, March 15, 2017 — Many people take large doses of vitamin C believing it will improve their health, prevent colds or reduce the risk of disease — but will it really? And when choosing a vitamin C supplement, can consumers be sure it contains what it claims? To ...

News Release

February 13, 2014

Calcium, Vitamin C, and Fish Oil Supplements Drop in Use, Probiotics Rise According to Survey

White Plains, New York, February 13, 2014 — A recent survey of over 10,000 people who use dietary supplements shows that the use of calcium, vitamin C and fish oil supplements fell during 2013 while the use of probiotics increased.

Recalls & Warnings

October 08, 2019

Seller of Tea, Colloidal Silver, Homeopathic Products Warned for Manufacturing Violations

On September 12, 2019, the FDA issued a warning letter to Herbal Healer Academy, Inc.

Recalls & Warnings

May 20, 2005

Seller of "Ocular Nutrition" Supplement Settles FTC Charges

On March 16, 2005, The Federal Trade Commission (FTC) announced that Hi-Health Supermart Corporation (Hi-Health) and its owner, Simon Chalpin, settled FTC charges that they made unsubstantiated advertising claims that their product – Premier Formula for Ocular Nutrition-Optim3 (Ocular Nutrition) – ...

Recalls & Warnings

February 19, 2005

Seller of Eye Supplement Purporting to Restore Vision and Eliminate "Floaters" Settles FTC Charges

On February 15, 2005, the Federal Trade Commission (FTC) announced that Hi-Health Supermart Corporation (Hi-Health) and its owner, Simon Chalpin, have settled FTC charges that they made unsubstantiated advertising claims that their product – Premier Formula for Ocular Nutrition-Optim3 (Ocular ...

News Release

December 16, 2009

"Eye health" supplements vary widely in formula but product quality is high according to

"Eye Health" Supplements Vary Widely in Formula But Product Quality is High According to

News Release

July 12, 2007 finds lutein & zeaxanthin supplements vary widely in strength but most meet ingredient claims — Right amount of antioxidant may help prevent macular degeneration and improve vision

WHITE PLAINS, NEW YORK — July 12, 2007 — announced today that all but one of the thirteen lutein and zeaxanthin supplements it recently chose to test met quality standards.

Recalls & Warnings

October 18, 2017

FDA Warns Seller of Arthritis, Blood Pressure, Diabetes Supplements For Making Drug Claims

On August 15, 2017, the FDA issued a warning letter to Years to Your Health, Inc., following an inspection of the company's website which found a number of their products to be misbranded, as they contained drug claims.

Recalls & Warnings

June 06, 2017

Seller of Vision, Cholesterol, Prostate Supplements and More Warned for Drug Claims

On May 25, 2017, the FDA issued a warning letter to Herbal Doctor Remedies following a facility inspection and review of the company's websites,, and www.theraherb.

News Release

December 20, 2004

Testing of Alpha-lipoic acid supplements by finds most meet label claims but one with only 15% of ingredient — Antioxidant of potential benefit in diabetes and other conditions

WHITE PLAINS, NY — December 20, 2004 — announced today that one of 21 alpha-lipoic acid supplements recently tested contained only 15% of the alpha-lipoic acid that it claimed. Alpha-lipoic acid is an antioxidant naturally produced in the body.

News Release

January 29, 2004 finds lutein supplements vary widely in strength but most meet ingredient claims — Right amount of antioxidant compound may reduce risk of blindness

WHITE PLAINS, NY — January 29, 2004 — announced today that only one of the 19 lutein/zeaxanthin supplements it recently tested failed to contain the claimed ingredients. Although product quality was generally high, ConsumerLab.

Recalls & Warnings

August 22, 2013

UK Warns Against a Weight Loss Supplement Still Available to Americans

The British government has identified the "fat-burner" supplement "I Force Dexaprine XR" as an unlicensed medical product and is instructing its retailer to remove it from the market, according to a report published in

Recalls & Warnings

July 05, 2013

Seller of Vision Supplement Warned For Drug Claims

On June 25, 2013, the FDA issued a warning letter to Nutrient Synergy, Inc., following a review of the company's website which found statements made about the dietary supplement Nepretin to be drug claims.

Recalls & Warnings

August 30, 2012

Supplement Company Warned For Medical Claims and Misbranding Of Omega-3, CoQ10, Noni Juice And More

On July 12, 2012, the FDA issued a warning letter to Alfa Vitamins Laboratories, Inc.

Recalls & Warnings

March 31, 2005

FDA Warns Marketer of "Vitamin O" Product to Cease Unsubstantiated Claims

The U.S. Food and Drug Adminstration (FDA) has sent a Warning Letter (dated February 8, 2005) to Donald L. Smyth, President, R-Garden Inc., and Rose Creek Health Products, Inc. warning that its "Vitamin O" product was, among other things, being marketed with unsubstantiated health claims.