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Inactive Ingredients

Find out about the safety and regulation of added ingredients in supplements, protein drinks and bars and more, including cellulose, lactose, magnesium stearate, methylcellulose, microcrystalline cellulose, polyethylene glycol (PEG), povidone, sorbitol, starch, and xylitol, coloring agents such as Blue 1 Lake, D&C Yellow No. 5, Red 40 Lake, Yellow 5 Lake and Yellow 6 Lake and sweeteners such as aspartame, sucralose, maltodextrin.

Inactive Ingredients Review

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CL Answer

Are the inactive ingredients I see listed on my supplement label necessary? Are they dangerous?

Learn more about the inactive ingredients found in supplements, including coloring agents, and their safety.

Man Reading Supplement Bottle Ingredients

Product Review

Joint Health Supplements for Pets Review (Glucosamine, Chondroitin, MSM & Boswellia)

See Which Pet Supplements for Joint Health Passed Our Tests and Which Didn't!

Joint Health Supplements for Pets

CL Answer

Should I be concerned about supplements that contain Polysorbate 80? Is it safe?

Find out if polysorbate 80 is a safe ingredient in supplements.

Is Polysorbate 80 Safe? -- woman looking at supplement label

Product Review

Toprol XL vs. Generic Metoprolol Succinate Extended-release (ER) Tablets Review Article

Choose the Best Blood Pressure Medication. Find Out Why Some Generic Blood Pressure Medications Are Not the Same as the Original & May Increase Blood Pressure or Have Other Disturbing Side Effects.

Toprol vs Generic Metoprolol

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 ConsumerLab.com

CL Answer

Titanium dioxide is listed as an ingredient in my supplement. Is it safe?

Titanium dioxide in supplements might have you concerned. Learn more about titanium dioxide - FDA status and evidence from studies on cancer.

Titanium Doxide Safety -- close up of broken white pills

CL Answer

I read an article stating that some of the ingredients in Centrum multivitamins may be dangerous or toxic. Is that true?

Learn more about the safety of ingredients in Centrum, including binders, fillers, and coloring agents.

Inactive Ingredients in Centrum -- Bottle of Centrum Vitamins

CL Answer

What is magnesium stearate, what is it made from, and is it dangerous?

Learn more about magnesium stearate and its safety, based on evidence from clinical studies.

Is magnesium stearate safe? -- woman looking at ingredients on supplement label

CL Answer

What is Lutigold Lutein? And why is the capsule of one brand of lutein so much larger than that of another brand, if the amount of lutein on the label is the same?

Learn more about lutein supplements like Lutigold, FloraGlo, and XANGOLD, and understand the difference in capsule sizes.

Lutein

Clinical Update

11/29/2022

Tooth Stains from Food Colorants

Find out which food colorants appear to increase staining of the teeth in the Coloring Agents section of our Inactive Ingredients Review.

CL Answer

Which ingredients should toothpastes and other dental products contain, and which should be avoided?

Learn about ingredients you want in your toothpaste, mouthwash and other dental products and which ingredients you may want to avoid.

Toothpaste in the shape of question mark coming out from toothpaste tube

CL Answer

What is the best sunscreen based on safety and efficacy?

We’ve boiled down the latest research about mineral and chemical sunscreens, including product tests, to help you choose the best sunscreen (which will depend on whether you expect to be in or out of the water). We also list popular sunscreens that have, or have not, been found to contain cancer-causing compounds (benzene and benzophenone).

Carcinogens in Sunscreens - Bottle of sunscreen with a question mark

Product Review

Turmeric and Curcumin Supplements and Spices Review

See Our Top Picks Among Turmeric Products

CL Answer

Does the talc added to Centrum Silver and other vitamins pose a risk of cancer?

Find out if talc, an inactive ingredient in many vitamins and supplements, is safe to consume, and learn about asbestos in talc and cancer risk and USP-grade talc vs. food-grade talc and cosmetics-grade talc. ConsumerLab.com's answer explains.

Talc in Vitamins & Cancer Risk -- broken white tablet

Product Review

L-Lysine Supplements Review

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

Product Review

Cinnamon Supplements and Spices Review

CAUTION: Some Cinnamon Products High in Toxin. See Which Passed or Failed and our Top Picks!

Cinnamon Supplements and Spices Tested by ConsumerLab.com

Product Review

Psyllium Fiber Supplements Review

Find the Best Psyllium Fiber Supplement and Avoid Lead.

Psyllium Review 2024

CL Answer

Should I be worried that my supplement contains "caramel coloring IV"? I've heard that it has been linked to cancer.

Learn more about caramel coloring IV, including evidence from studies on cancer.

Woman Reading Supplement Bottle Label

CL Answer

Is it better to use a powdered product that you mix with liquid than to take a pill? I was told that the vitamins will be more completely absorbed. Is that true?

Learn more about taking supplements & multivitamins in powder or tablet form, including tips on how to get the most from your supplement.

Orange Powder Dissolving in Glass of Water

Clinical Update

10/31/2023

Can B-12 cause allergic reactions?

Although rare, vitamin B-12 can cause allergic reactions, but so can “inactive” ingredients in B-12 and other supplements. For details see the Risks of B-12 section of our Vitamin B-12 Review, which includes our Top Picks for B-12.

Clinical Update

5/25/2019

Concern With a Colorant

Titanium dioxide is a common white colorant in foods and supplements. A recent study in mice, however, suggests that it may affect the gut. For details, see the updated Titanium Dioxide section of the Inactive Ingredients/Excipients article.

Clinical Update

5/11/2021

Whitener In Many Pills May Not Be Safe

Titanium dioxide, which is commonly used to whiten pills, is not safe according to the European equivalent of the FDA. Find out why in our Review Article about Inactive Ingredients.

Clinical Update

12/07/2021

Can a Natural Colorant Cause Adverse Effects?

A CL member recently asked if purple carrot powder in his supplement might have caused symptoms such as chest tightness and headache. Find out in our updated article about Inactive Ingredients/Excipients.

Clinical Update

3/31/2023

Phosphate Additives in Food

Are phosphate additives, such as trisodium phosphate and dicalcium phosphate, a health concern? Find out in our article about Inactive Ingredients in supplements and foods.

Clinical Update

10/14/2022

Cancer-Causing Sweetener?

Acesulfame potassium is a sweetener in some of the products that we have tested. A CL member asked if it can cause cancer. Find out in the Sweetening agents section of our Inactive Ingredients/Excipients in Supplements Review Article.

Clinical Update

8/18/2023

Benzene in Supplements?

Can sodium benzoate, a preservative used in supplements and foods, be converted to benzene, a toxic compound? Find out what a recent study showed in our article about Inactive Ingredients.

Also see our articles about benzene in sunscreens and deodorants.

Clinical Update

8/22/2023

Sodium Benzoate and Benzene

Vitamin C can promote the conversion of sodium benzoate, a preservative, to benzene, a toxic chemical. Should you be worried about consuming products such as lemon juice (a source of vitamin C) preserved with sodium benzoate? Find out in the Preservatives section of our article about Inactive Ingredients.

CL Answer

What is UC-II and does it help joints?

What is UC-II (undenatured type 2 collagen - InterHealth Nutraceuticals) and do clinical studies show that it works for joint health?

UC-II Collagen for Joint Pain? -- man with knee pain

CL Answer

I have type 2 diabetes. Should I be concerned about ingredients like maltodextrin and maltitol that are found in some protein bars and drinks?

Learn more about maltitol and maltodextrin and their effects on blood glucose levels for people with type 2 diabetes.

Protein Bars and Powder

CL Answer

I read that turmeric may be a GI irritant. I have GI problems and wonder if I should avoid turmeric and curcumin?

Find out if turmeric/curcumin supplements can cause gastrointestinal irritability.

Is turmeric a stomach irritant? -- Turmeric Supplement

CL Answer

Is soy in supplements good or bad for you?

Find out about the health benefits and/or safety concerns related to soy constituents (including soy isoflavones, soy protein, soy lecithin, and soybean oil), and learn how you can avoid soy in supplements if necessary.

Scoop of soy protein isolate placed among soybeans

Product Review

Probiotic Supplements Review (Including Pet Probiotics)

Probiotics: See What They Really Contain and Our Top Picks

CL Answer

Does AHCC (active hexose correlated compound) have anticancer or antiviral benefits, and is it safe?

Learn about AHCC (active hexose correlated compound), including whether it is beneficial for liver, pancreatic, or prostate cancer, chemotherapy-related side effects, or the flu, and if it is safe.

Capsules of AHCC in wooden spoon in front of green leaf

Product Review

Taurine Supplements Review for People, Dogs, and Cats

Find the Best Taurine Supplements. Learn When to Use Taurine and Which Supplement is Best.

Taurine Supplements Reviewed by ConsumerLab.com

Product Review

Alginate Supplements Review (For Reflux)

See Our Top Pick Alginate Supplements For Reducing Symptoms of Gastroesophageal Reflux (GERD)

Alginate supplements reviewed by ConsumerLab.com

CL Answer

Are enteric coated supplements better than non-enteric coated ones?

Learn about the pros and cons of enterically coated supplements, including ingredient absorption,safety and price.

Glass of Water and White Pill

CL Answer

What are trace minerals and do I need them?

Trace minerals include boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, zinc, and others. Find out what they do, how much of each trace mineral you should be getting, and who's most likely to be deficient in these minerals.

Trace Minerals - What are they and do you need them?

CL Answer

How do the COVID-19 vaccines compare in terms of efficacy, safety and side effects? How, when and where do I get the COVID-19 vaccine?

Find out how the COVID-19 vaccines from Pfizer and Moderna compare and learn how when and where you can get the COVID-19 vaccine.

Older woman getting an injection

CL Answer

I take levothyroxine (Synthroid), a thyroid hormone to treat hypothyroidism. Are there supplements or foods I should avoid, or be taking, due to this drug?

Is taking certain supplements and hypothyroidism medications bad? Learn which supplements can interact with thyroid hormone medications like levothyroxine (Synthroid), thyroid hormone levels, and laboratory tests.

Levothyroxine (Synthroid) Supplement Interactions

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

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

Find the Best Vision Supplement Based Our Tests

CL Answer

Some websites claim that synthetic vitamin C in supplements may be a combination the active "L" form and the inactive "D" form of ascorbic acid. Is that true? Should I be concerned?

Learn more about the forms of vitamin C.

Vitamin Bottle and Pills Scattered on White Background

CL Answer

The probiotic I am taking looks pink. Does this mean it is spoiled or no longer "active"?

Find out if a pink probiotic is safe, since they are usually white.

Man Examining Probiotic

CL Answer

Tablets I purchased are becoming "crumbly" after a few weeks and are easy to break. Is there a problem with this supplement?

Should you be concerned if your supplement tablets have started to crumble? Learn more including the best way to keep pills from getting soft.

Are Broken Tablets Safe? -- broken tablets on table

CL Answer

I heard the S-form of alpha-lipoic acid is bad for me. Why is it in my supplement?

Learn more about R-form alpha-lipoic acid and S-form alpha-lipoic acid and their activity, as described by experts at ConsumerLab.com.

Chemical Structure of Alpha Lipoic Acid on Pink Background

Product Review

Huperzine A Supplements Review

Choose the Best Huperzine A Supplement. CL Tests Reveal the Best Huperzine A Supplements for Memory.

Huperzine A Supplements Tested by ConsumerLab.com

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

News Release

December 02, 2010

ConsumerLab.com Finds Lower-priced Resveratrol Supplements Pass Tests While Some Higher-priced brands flunk

WHITE PLAINS, NEW YORK — DECEMBER 2, 2010 — ConsumerLab.com reported today that tests of supplements containing resveratrol — a compound promoted as "life-extending" — revealed that two products provided only 43.4% and 86.

CL Answer

Supplements That May Be Needed When Following a Gluten-Free Diet

Find out if supplements such as folate, vitamin B-12, niacin, thiamin, iron, vitamin D, and/or fiber are needed when following a gluten-free diet. Also learn how to find gluten-free supplements on ConsumerLab.com.

Woman holding her hand in front of a slice of bread to signify a gluten free diet

CL Answer

Do sea moss and carrageenan have health benefits? Are there risks?

Sea moss is promoted for thyroid health, boosting immunity, improving gut health, and other uses. Find out if it works and learn about possible side effects of sea moss and its constituent, carrageenan.

Sea moss in a clear bowl next to a wooden spoon on the countertop

Product Review

Breast Enhancement Supplements Review Article

Do Breast Enhancement Supplements Really Work? See the Evidence For and Against Breast Enhancement Supplements.

Do Breast Enhancement Supplements Work?

CL Answer

Do arnica pills, gels, creams, or sprays reduce bruising, pain, or swelling?

Find out if arnica pills, gels, creams, or sprays can reduce bruising, pain, or swelling, help with varicose veins, or muscle pain after exercise.

Arnica Gel and Cream for Bruises and Pain -- tube of arnica cream

CL Answer

What are the best bug sprays to prevent tick and mosquito bites? Is the insecticide permethrin safe to use?

Find out how permethrin sprays differ and which can be used on sheets and sleeping bags versus clothing

Variety of insect repellents on store shelf

News Release

March 17, 2008

As problems surface, Consumerlab.com and the people's pharmacy ask FDA to disclose differences between generic and original drugs

WHITE PLAINS, NEW YORK AND DURHAM, NORTH CAROLINA — MARCH 17, 2008 — An investigation by ConsumerLab.

CL Answer

What are the health benefits of manuka honey, and is it safe?

Manuka honey health benefits, how it differs from common, store-bought honey, safety, evidence for using manuka honey for wounds, sore throat and cough, constipation and more.

Health Benefits of Manuka Honey -- jar of manuka honey

Recalls & Warnings

May 14, 2016

Xylitol in Supplements Poses Danger for Dogs

On May 12, 2016, the FDA warned consumers that xylitol, a popular sweetener found in chewable vitamins, chewing gum, breath mints, toothpaste and a variety of other products, is toxic to dogs.

Recalls & Warnings

February 13, 2013

FDA Warns Maker of Weight Loss and Whey Protein Supplements For Manufacturing Violations and Misbranding

January 25, 2013, the FDA issued a warning letter to dietary supplement manufacturer SciLabs Nutraceuticals, following a facility inspection which found the company's dietary supplements and supplement ingredients, including N-Large 2, Flo-Gard AB, Nitrogen Glutamine capsules, Nutritech nutritional ...