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CL Answer

Can biotin supplements really strengthen nails or improve hair? Can other supplements help?

Learn more about strengthening brittle nails with vitamin B-7 (biotin), based on clinical evidence.

Supplements for Brittle Nails -- healthy nails

CL Answer

Do Sugar Bear Hair Vitamins make hair shine, nails stronger, and help both to grow? They taste good but are super expensive.

Info on Sugar Bear Hair vitamins. Do they make hair shine, nails stronger and help hair and nails grow?'s answer explains.

Do Sugar Bear Vitamins Work? -- bottle of Sugar Bear vitamins

CL Answer

Does silica have health benefits? What is BioSil, and can it really increase collagen production and strengthen hair, skin, nails and bones?

Information about the health effects of silica (silicon dioxide) and orthosilicic acid (an ingredient in BioSil), including whether these forms of silicon can really increase collagen production, thicken hair, strengthen nails & bones.

Does BioSil Strengthen Hair, Skin and Nails? -- Bottle of BioSil

CL Answer

Do hair loss supplements, such as Viviscal, Hair La Vie, and Nutrafol, or topical essential oils work?

Vitamins and supplements that may help with hair loss and thinning, including saw palmetto, beta-sitosterol, protein, iron, and vitamin D.

Supplements for Hair Loss -- woman looking at hairbrush

CL Answer

What is the difference between cysteine and cystine?

Find out the difference between cysteine and cystine amino acids, including where each is found and their functions.

Young Woman Taking Supplement

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

Does tea tree oil work for getting rid of athlete's foot?

Learn more about tea tree oil and its effects on foot fungus (known as athlete’s foot, tinea pedis, or “ringworm” due to the lesion that can occur) and how it can be as effective as some, but not all, over-the-counter antifungal treatments. ConsumerLab explains.

Tea Tree Oil for Athlete's Foot? -- Bottle of Tea Tree Oil

Clinical Update


Does MSM Help Hair and Nails?

Find out if research supports MSM (methylsulfonylmethane) for improving nails or hair in the MSM section of our Joint Health Supplements Review.

Also see our article about biotin and other supplements for hair and nails.

Product Review

Bone Broth Review

Find the Best Bone Broth. Find Out How Much Collagen and Sodium Is Really In Popular Bone Broths.

Bone Broth Supplements Reviewed by

Product Review

Collagen Supplements Review

See our Top Picks for Wrinkles and Joints

CL Answer

Which is the best pulse oximeter for home use?

Best pulse oximeter for home use (COVID-19, asthma and COPD). Differences between home use and FDA-approved medical pulse oximeters.

Best Pulse Oximeter for Home Use -- Pulse Oximeter

Clinical Update


Eggshell Membrane for Hair, Skin, Nails?

Does supplementing with eggshell membrane (which contains collagen and elastin) improve hair, skin, or nails? See what a recent study found in the What It Does section of the Collagen Supplements Review. Also see our Top Picks among collagen supplements.

Clinical Update


Nail Growth

Does biotin help nails to grow faster? Find out what research suggests, and also learn which topical treatment for hair growth may help nails to grow, in the Biotin section of our B Vitamin Supplements Review, which includes our Top Picks for biotin and other B vitamins.

CL Answer

Is ingesting colloidal silver helpful for any condition and is it safe to use?

Find out if there is evidence showing colloidal silver can help to treat infections, boost the immune system, help with arthritis and more, plus find out if colloidal silver can cause blue skin or other side effects.

Benefits and Risks of Colloidal Silver? -- dropper bottle of colloidal silver

Clinical Update


Hair & Nail Supplements Can Skew Lab Tests

There are reports of high-dose biotin (common in "hair and nail" supplements) causing false readings on blood tests. Be sure to tell your doctor if you're taking high-dose biotin. Get the details in the Biotin section of the B Vitamin Supplements Review.

CL Answer

Does collagen taken as a supplement help with arthritis? I'm seeing it in products for joint health.

Learn more about collagen supplements, including evidence from clinical studies on arthritis and muscle strength and safety.

Collagen Supplements for Joint Pain

Clinical Update


Biotin vs. Biothin

What is the difference between biotin and Biothin? Find out in our article about biotin for nails and hair.

CL Answer

Do collagen or hyaluronic acid supplements really help aging or wrinkled skin?

Find out if collagen & hyaluronic acid supplements really help for aging or wrinkled skin and for skin care.

Collagen Supplements for Wrinkles? -- woman looking closely at her face in a mirror

CL Answer

Which supplements can help treat anemia? Do any supplements cause a low red blood cell count?

Find out which vitamin and nutrient supplements can help prevent and treat anemia in people who are nutrient deficient and learn which supplements may cause low blood cell counts, especially when used in excess.

Woman holding various vitamins and supplements in her hands

CL Answer

What is C15:0 fatty acid (found in fatty15), and does it have health benefits?

C15:0 fatty acid in fatty15 is promoted for “healthier hair & skin, balanced metabolism, and deeper sleep,” as well as “slowing the aging process.” Find out if it works.

Bottle of fatty15 with white background

Clinical Update


Biotin Interference With Vitamin D Test

Last week we reported that high doses of biotin (found in B complexes and hair and nail supplements) can interfere with certain blood tests. A study recently showed that biotin can also artificially inflate a test for vitamin D. Get the details in the "Biotin" section of the B Vitamin Supplements Review >>

Clinical Update


Growing Concern with Biotin Causing False Lab Results

Biotin (a B vitamin found in B-complex and hair and nail supplements) can interfere with laboratory results resulting in the missed diagnosis or misdiagnosis of cardiovascular and hormonal conditions, such as Graves' disease (a form of hyperthyroidism). Physicians and lab personnel may be unaware of this interference. For details, see the "Biotin" section of the B Vitamins Review >>

Clinical Update


Silica for Dental Implant Inflammation?

Can a form of silica typically promoted for hair, skin, nail and bone health also help reduce inflammation and bone loss around dental implants? See what a recent study found in our updated article about Silica Supplements.

Clinical Update


Right Dose of Vitamin D to Reduce Falls

As we've reported in the past, vitamin D can reduce falls in older people, but too much can increase falls. A new study helps nail down the ideal dose and blood level to reduce falls. For details, see the "What It Does" section of the Vitamin D Supplements Review >>

Clinical Update


Biotin for Skin Health?

Biotin has been promoted for reducing wrinkles, but does clinical research support this? Find out in the Biotin (B-7) section of our B Vitamin Supplements Review, which also discusses the evidence for biotin for treating brittle nails and hair loss.

Also, see our CL Answer about supplements for reducing wrinkles and tightening the skin.

Clinical Update


Colloidal Silver & Discoloration

Regular ingestion of colloidal silver can cause a permanent change in skin color and, as recently reported, discoloration of nails. Learn more in our article about colloidal silver.

Clinical Update


Pulse Oximeter Accuracy

Can you get an accurate pulse oximeter measurement while wearing nail polish?

Also learn how to get the most accurate reading with pulse oximeters and see our choice for best home pulse oximeter.

Clinical Update


Symptoms of Vitamin A Deficiency

Although not common, be aware of signs of vitamin A deficiency involving the eyes, skin, and nails, as exemplified by a recent case. Get the details (including medical conditions which can cause it) in the What It Does section of our Vitamin A Supplements Review. Also see our Top Picks among vitamin A supplements.

Clinical Update


Does fatty15 work?

Does pentadecanoic acid (C15:0 fatty acid), found in the supplement fatty15, slow aging, or improve metabolism, sleep, hair or nails? Find out in our new article about pentadecanoic acid.

Clinical Update


Getting C15:0 Fatty Acid from Food?

Can a person get a clinically relevant dose of C15:0 fatty acid (in the supplement fatty15 promoted for hair, nails, sleep and aging) from food? Find out in the Getting C15:0 fatty acid from food section of our article about C15:0 fatty acid.

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

What is Perque Bone Guard Forté? It is safe and effective for bone health?

Find out about the ingredients in Perque Bone Guard Forté, including which ingredients may be beneficial for osteoporosis and bone health and which may be a safety concern.

Bottle of Perque Bone Guard Forte

CL Answer

I thought the B vitamins were all water soluble and did not build up in the body, so you would not build up toxic levels. Am I wrong?

Learn more about water-soluble B vitamins including niacin, B6, B12 and folic acid, and why taking too much of these vitamins can be toxic. See the symptoms of overdose and toxicity from B vitamins.'s answer explains.

B Vitamins

Product Review

Vitamin C Supplements Review

Find the Best Vitamin C Supplements

Vitamin C Review 2023

CL Answer

Risks of Too Many Vitamins & Supplements

Taking too many vitamin supplements -- or taking too much of a particular supplement -- can have short and long-term adverse effects.

Too Many Vitamins

CL Answer

Which vitamins and supplements should be stopped before getting blood work and laboratory tests?

Find out which vitamins and supplements can interfere with blood, urine or stool tests, and imaginging tests. 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

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

CL Answer

What are the health effects of turkey tail mushroom and is it safe?

Learn about the possible health effects of turkey tail mushroom, including its use as adjuvant treatment for cancer and for boosting immune function, plus get information about possible side effects and find out why ConsumerLab has not yet tested turkey tail products.

Turkey tail mushrooms growing on the side of a tree

News Release

July 26, 2023

Best Collagen Supplements for Skin and Joints, According to ConsumerLab Tests

White Plains, New York, July 26, 2023 —  Collagen supplementation may modestly reduce wrinkles and the appearance of cellulite, and moderately decrease joint and tendon pain and improve flexibility in people with osteoarthritis.

Product Review

Magnesium Supplements Review

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

Magnesium Review 2024

CL Answer

Do any drugs prevent or treat COVID-19?

Learn more about drugs for preventing and treating COVID-19, including who can receive these treatments, when the treatments should be initiated, and which appear to be effective against Omicron variants.


CL Answer

What are the benefits of grape seed extract?

Learn about the health benefits of grape seed extract, and find out it improves venous insufficiency, leg swelling, swelling after surgery, or can help to lower blood pressure.

Benefits of Grape Seed Extract -- grapes and seeds

Recalls & Warnings

May 09, 2024

Walnuts, Other Nuts, Pumpkin and Sunflower Seeds Recalled Due to Undeclared Allergens

On May 8, 2024, Texas Pecan recalled various lots of the company’s 1 lb. and 8 oz.

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

News Release

June 25, 2019

ConsumerLab Tests Reveal Best B Vitamin Supplements -- 19% of B Vitamin Supplements Fail CL's Tests of Quality

White Plains, New York, June 25, 2019 — B vitamins and complexes are among the most popular supplements sold in the U.S. because B vitamins are essential for a wide range of functions in the body.

Recalls & Warnings

November 09, 2019

Biotin Supplements Can Cause False Lab Test Results

On November 5, 2019, the FDA reminded consumers and health care providers that high amounts of biotin (vitamin B-7), found in many supplements, can significantly interfere with certain lab tests and cause incorrect results that may go undetected.

News Release

September 27, 2012 Reveals How Much Caffeine is in Energy Drinks -- Also Finds Some Drinks and Dietary Supplements Don't Contain Claimed Amounts of B Vitamins

White Plains, New York — September 27, 2012 — Energy shots and drinks are promoted to keep you alert and energized, attributing their effects to special formulas often "packed with B vitamins and nutrients to make it last," as a commercial for 5-hour Energy proclaims.

Recalls & Warnings

June 03, 2008

Selenium Toxicity from a Supplement

The June 2008 issue of Annals of Internal Medicine provides a recent case report describing the symptoms of a woman and her husband after taking a liquid supplement found to contain excessive selenium.