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Product Review

Vitamin D Supplements Review (Including Calcium, Magnesium, Vitamin K, and Boron)

Find the Best Vitamin D Supplement and Avoid Problems

Vitamin D Review 2024

Product Review

CoQ10 and Ubiquinol Supplements Review

Find the Best CoQ10 and Ubiquinol Supplements and Learn How They Differ

CoQ10 2024

Product Review

Astaxanthin Supplements Review

See Which Astaxanthin Products Passed or Failed CL's Tests

Astaxanthin supplements reviewed by ConsumerLab.com

Product Review

L-Arginine Supplements Review

Choose the Best L-Arginine Supplement. Find Out Which L-Arginine Supplement Passed CL's Tests.

L-Arginine Supplements Reviewed by ConsumerLab.com

Product Review

Fish Oil, Krill Oil, and Algal Oil Omega-3 (DHA & EPA) Supplements Review

See Our Omega-3 Top Picks and Avoid Rancid Fish Oils.

Fish Oil and Other Marine Oil Supplements Reviewed by ConsumerLab.com

Product Review

Dark Chocolates, Cocoa Powders and Supplements Review

Many Dark Chocolates and Cocoa Powders Fail Safety Tests

Cocoa and Dark Chocolate Review 2025

Product Review

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

See Our Top Picks and Which 5 Failed Testing

B Vitamins Review 2024

Product Review

PQQ (Pyrroloquinoline Quinone) Supplements Review

Learn What PQQ Does and Which PQQ Supplements are Best

Product Review

Turmeric and Curcumin Supplements and Spices Review

See Our Top Picks Among Turmeric Products

Turmeric Review 2025

Product Review

NAC (N-Acetyl Cysteine) Supplements Review

Choose the Best NAC Supplement and Save Money

NAC Review 2026

Product Review

Nitric Oxide Supplements (Bodybuilding and Athletic Performance) Review Article

Do Nitric Oxide Supplements Really Work? Find Out If Nitric Oxide Supplements Really Build Muscle or Improve Performance.

Nitric Oxide Supplements Review

Product Review

Garcinia Cambogia (HCA) Supplements Review

Find the Best Garcinia Cambogia Supplement. Choose Carefully! Most Garcinia (HCA) Weight Loss Supplements Lack Listed Amount of Ingredient .

Garcinia Cambogia (HCA) Supplements Reviewed by ConsumerLab.com

Product Review

Hemp Seed Review

We Found That 33% of Products Were Spoiled

Hemp Seed Review 2026

Product Review

Resveratrol Supplements Review (From Red Wine, Knotweed, and Other Sources)

See Which Resveratrol Supplements Were Best In Our Tests and Comparisons. Learn What Resveratrol Can and Can't Do.

Review of resveratrol supplements tested by ConsumerLab.com, including ratings and comparisons of product quality, price, and ingredients.

Product Review

Black Currant, Borage, Evening Primrose, Flax and Hemp Seed Oil Review

Choose the Best Flaxseed and Other Oils Based on Our Tests.

Omega 3 and 6 Seed Oil Review 2025

Product Review

Phosphatidylserine (PS) Supplements

Find out if phosphatidylserine helps with memory and which products are best.

Phosphatidylserine Review 2024

Product Review

L-Lysine Supplements Review

Read L-Lysine Labels Carefully. Some Can Fool You.

Product Review

Avocado Oil Review

Find the Best Avocado Oil for Purity, Freshness and Taste. Some Others May Include Rotten Avocado or Other Oils.

Avocado oil reviewed by ConsumerLab.com

Product Review

L-Tryptophan and 5-Hydroxytryptophan (5-HTP) Supplements Review

Choose the Best L-Tryptophan and 5-HTP Supplements. CL Tests Identify High Quality L-Tryptophan and 5-HTP (5-Hydroxy-L-Tryptophan) at the Best Value.

L-Tryptophan and 5-HTP (5-Hydroxy-L-tryptophan) Supplements Reviewed By Consumerlab.com

Product Review

Elderberry Supplements Review

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

Elderberry Supplements Reviewed by ConsumerLab.com

Product Review

Quercetin & Rutin Supplements Review

Quality's a Concern With Quercetin and Rutin Supplements -- Only 17% of Claimed Amount In One

Product Review

Weight Loss Supplements Review (7-Keto DHEA, Forskolin and Stimulant Blend Supplements)

Choose the Best Weight Loss Supplement. Be Careful With Weight Loss Supplements — Few Pass Quality Testing and Safety Review.

Weight Loss Supplements Tested by ConsumerLab.com

Product Review

Prebiotic Supplements Review

You Can't Tell How Much Fiber Is Really In Most Prebiotics Without Testing

Prebiotics 2024 Expanded Review

Product Review

Alpha-Lipoic Acid Supplements Review

Choose the Best Alpha-Lipoic Acid Supplement — See the Amounts of Active "R-Isomer" We Found

Product Review

Black Seed Oil Review

Find Out Which Black Seed Oil Supplements Passed or Failed Our Tests. See Our Top Picks.

Black Cumin Seed Oil Review 2025

Product Review

Licorice and DGL Supplements, Candies, and Tea Review

What's In Your Licorice? Find Out and Avoid Problems.

Licorice & DGL Review 2025

Product Review

Red Yeast Rice Supplements Review

Only 2 of 7 Red Yeast Rice Supplements Approved in CL Tests

Red Yeast Rice Review 2026 3

Product Review

Apple Cider Vinegar Review — Bottled Liquids and Supplements

Find the Best Apple Cider Vinegar and Avoid Fakes.

Apple Cider Vinegar Review

Product Review

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

Find the Best Vision Supplement Based Our Tests

Product Review

Vitamin K Supplements Review (Including Calcium, Vitamin D, Magnesium & Boron)

Find Out If It's Worth Taking Vitamin K and Which Products Are Best

Vitamin K Review 2024

Product Review

Menopause Supplements Review (Soy and Red Clover Isoflavones, Black Cohosh) and Progesterone Creams

Choose the Best Menopause Supplement. Find Out Now Which Soy Isoflavone, Red Clover, Black Cohosh, and Progesterone Products Have the Active Compounds You Want!

Menopause Supplements Tested by ConsumerLab.com -- Soy and Red Clover Isoflavones, Black Cohosh, and Progesterone Cream

Product Review

Iron Supplements Review (Iron Pills, Liquids and Chews)

See Which Iron Supplements Are CL's Top Picks for Different Needs

Product Review

Collagen Supplements Review

See our Top Picks for Wrinkles and Joints

Product Review

Calcium and Bone Health Supplements Review (Including Vitamins D & K, Magnesium and Boron)

See Which Bone Health Supplements Are Top Picks and Which Fail

Calcium Review 2024

CL Answer

Do collagen supplements impact cholesterol levels or reduce risk factors for atherosclerosis?

Collagen has been studied for its effects on cholesterol levels and atherosclerosis risk factors, but its effects are still not clear.

Collagen powder and collagen pills

Product Review

Fruits, Veggies, and Other Greens Supplements Review (Including Spirulina and Chlorella)

Avoid Lead in Greens, Problems with Pills, and Don't Give Up Eating Whole Foods.

Greens Review Oct 2023

Product Review

Joint Health Supplements Review (Glucosamine, Chondroitin, MSM, Boswellia, Collagen and Turmeric)

18% of Joint Health Supplements Failed to Pass Our Tests. See Which Passed or Failed, and Our Top Picks.

Joint Health Supplements Review 2025

Product Review

Canned Tuna, Salmon, Sardines & Mackerel Review

Find Fish With the Least Mercury & Arsenic and Most Omega-3s

Canned Fish Review 2025

Product Review

Green Tea Review: Tea Bags, Loose Leaf Tea, Matcha Powders, and Supplements

Some green teas provide barely any green tea polyphenols, while some others are high strength. See the Test Results and Our Top Picks for Green Tea.

Green Tea Review 2024

Product Review

Magnesium Supplements Review (Including Calcium, Vitamins D & K, and Boron)

Find Out What Magnesium Does, Who Needs It, and Our Top Picks Among Supplements

Magnesium Review 2024

Product Review

Protein Powders and Shakes Review

Find Out Which Protein Products Passed or Failed Our Tests

Protein Review 2026

CL Answer

Do either phosphatidylserine or phosphatidylcholine help with memory and cognition? How are these supplements different?

Find out if phosphatidylserine or phosphatidylcholine supplements improve memory and cognition.

Brain Puzzle

CL Answer

How much calcium do you need each day, what forms are best, and how much is too much?

Learn about the recommended daily intake of calcium from food & supplements and why taking too much can be harmful. Also, learn about the forms of calcium that are available and which are best.

None

CL Answer

Which vitamins and supplements should be stopped before getting blood work, laboratory tests, or medical imaging?

Find out which vitamins and supplements can interfere with blood, urine or stool tests, and imaginging tests, like bone scans and MRIs. Learn how B vitamins such as biotin, niacin and riboflavin, as well as calcium supplements, St. John’s wort, vitamin C, and others supplements can affect test results, as well as common foods that may interfere with tests.

Vitamin & Supplements to Stop Before Blood Tests

CL Answer

Will pregnenolone help slow down aging or reduce chronic pain?

Learn more about the steroid hormone pregnenolone, including its effects in the body and on aging and chronic pain.

Elderly couple yoga pose in sunshine

CL Answer

What are the health benefits of bovine colostrum and is it safe?

Bovine colostrum is promoted for boosting immunity, preventing and treating diarrhea, and improving gut health, but does it really work? See the clinical evidence for bovine colostrum, including doses that have been used, as well as safety concerns, cost considerations, and the difference between regular bovine colostrum and hyperimmune bovine colostrum.

Bovine colostrum powder and capsule supplements

CL Answer

Do any supplements naturally suppress appetite and help with weight loss?

Learn which natural ingredients can suppress appetite and find if these natural appetite suppressants help with weight loss.

Container of natural appetite suppressant supplement with measuring tape and scale in background

CL Answer

Which supplements are best for seasonal allergies?

Find out which supplements are best for allergies and can help reduce seasonal allergy symptoms, including bromelain, curcumin, vitamin D, and CLA.

Supplements for Seasonal Allergies -- Woman Outside Sneezing

CL Answer

What is Nitric Oxide?

Nitric Oxide Supplements Review

CL Answer

What are the health benefits of serrapeptase?

Serrapeptase is a proteolytic enzyme. Learn more about its health effects, including whether evidence supports its use for pain, inflammation, and heart health.

Serrapeptase for Inflammation and Pain

CL Answer

What is lactoferrin and will it really strengthen my immune system?

Info about lactoferrin supplements, clinical evidence for strengthening the immune system, preventing or treating colds, gut health and treating H.

What is Lactoferrin? -- lactoferrin capsules and bottle

CL Answer

What are the health benefits of zinc carnosine, also called polaprezinc, and is it safe?

Find out if zinc carnosine is beneficial for any GI conditions, including stomach ulcers, Helicobacter pylori infection, taste disturbances, aspirin-induced small-bowel injury and oral mucositis, and learn if it is safe.

Zinc carnosine supplements in wooden spoon in front of oysters

CL Answer

Dandelion Tea & Supplements: Health Benefits and Safety

Find out about the potential health benefits of dandelion tea and supplements, as well as safety, side effects, and potential drug interactions.

A cup of dandelion root tea on wooden background

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

Supplements For Back Pain: What Helps, What's Hype

Some supplements may provide modest benefit for back pain, while others don't seem to work or haven't been evaluated for this use. Find out if supplements like collagen, devil's claw, PEA, pregnenolone, white willow bark, and others help.

Man holding lower back due to low back pain

CL Answer

Does WEEM Grow Hair and Is It Worth It?

WEEM Hair.Skin.Nails is marketed as a "clinically tested hair health blend.” Find out if it — or its ingredients — works for hair loss and if it's worth the price.

Bottle of WEEM Hair.Skin.Nails

CL Answer

Are Moringa Leaf Supplements Helpful and Safe?

Are moringa leaf supplements beneficial for diabetes, lowering cholesterol, lowering blood pressure, improving liver function, and other conditions, and are they safe? Find out.

Fresh moringa leaves under a white bowl containing moringa leaf powder that is next to capsules of moringa leaf

CL Answer

What is TUDCA (tauroursodeoxycholic acid)? Does it have any proven health benefits, and is it safe?

TUDCA information, including its potential health benefits, safety, possible interactions, and cost.

What is Tudca - white capsules poured out of container

Recalls & Warnings

June 23, 2020

Nine Hand Sanitizers May Contain Toxic Ingredient That Can Cause Serious Illness or Death

Update: (7/14/20) The FDA has warned consumers not to use forty-six more hand sanitizers that may contain methanol.