Biotin: The Pros, the Cons, and How Much You Should Take

by Amy Hendel, P.A. Health Writer

If you’re “into” healthy hair and nails then you’ve likely heard about or are taking biotin. Biotin has been hailed for decades as a supplement that can support healthy, strong hair and nails. It’s been getting some more attention recently because when you take this supplement, you need to be aware that it can interfere with certain blood level results (see below).

Let’s take a deeper look at biotin.

Biotin or B-7 is in the class of B vitamins and it’s typically found in small amounts in a variety of foods. It’s a water-soluble vitamin which means the body does not store it, but it can be metabolized by gut microbes, taken as a supplement, or sourced from food. It’s considered an essential nutrient because it helps convert food into fuel for the body to use, and it helps the body to metabolize carbohydrates, fats, and proteins.

The many names of biotin include: Biotina, Biotine, Biotine-D, Coenzyme R, D-Biotin, Vitamin B7, Vitamin H, Vitamine B7, Vitamine H, W Factor, Cis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric Acid.

You can become biotin deficient and the more common symptoms might be thinning of the hair (often with loss of hair color) or a red, scaly rash around your eyes, nose, or mouth. Other symptoms can include depression, listlessness, hallucinations, and tingling in the arms and legs. Of course, other conditions can induce these symptoms so it’s important to rule out other possible causes. Smoking has been linked to causing mild biotin deficiencies.

  • If you are biotin deficient, then taking biotin will restore balance and help to limit these symptoms.

  • Using biotin for skin rash in infants, specifically seborrheic dermatitis, is largely ineffectual.

  • Using biotin for hair loss not related to a deficiency has been shown to be helpful when taken orally along with oral zinc supplement and a locally applied cream containing clobetasol propionate (such as Temovate).

  • Combining biotin with another supplement containing chromium may help to modulate blood sugar levels in people who have poorly controlled diabetes.

  • Combining biotin with a chromium supplement may also have some efficacy in adjusting and improving HDL to LDL ratio in people with type 2 diabetes.

  • Biotin may help with diabetic nerve pain.

  • Biotin may help to increase thickness of fingernails and toenails in people with brittle nails.

  • Individuals on kidney dialysis may require biotin supplementation.

  • Biotin is also being studied as a possible adjuvant treatment for multiple sclerosis.

  • Biotin is not proven effective for treating hair loss due to chemotherapy.

When is use of biotin a problem?

In general, biotin can cause falsely normal or abnormal results. If you take Synthroid for hypothyroidism, it’s important to stop taking biotin several days before getting tested for your thyroid levels. Biotin can affect the blood test results (TSH levels). It can also affect tests for heart failure, pregnancy, cancer, and iron deficiency anemia. Recently, biotin was shown to interfere with testing for vitamin D levels. Biotin may also change how the liver processes certain medications so it’s important to always share any plans to take supplements with your doctor.

It’s always best to get nutrients directly from food. Daily goals for biotin are 30 micrograms for adults, and 35 micrograms for women who are breastfeeding.

Biotin-rich foods include:

  • Animal liver (watch saturated fat)

  • Egg yolks

  • Yeast

  • Nuts and seeds

  • Salmon

  • Dairy products (watch saturated fat)

  • Avocadoes

  • Sweet potatoes

  • Cauliflower

There’s a saying in the world of nutrition that “too much of a good thing is not good.” Biotin clearly has an important role in helping our bodies to process food; however, more is not better. Talk to your doctor and decide if you can access this important vitamin from food. If not, ask that your doctor recommend a brand and dose of biotin that will work for your personal health needs.

Amy Hendel, P.A.
Meet Our Writer
Amy Hendel, P.A.

Known as "The HealthGal", Amy Hendel P.A. is a medical and lifestyle reporter, nutrition and fitness expert, health coach and brand ambassador. Trained as a physician assistant, she maintains a health coach private practice in New York and Los Angeles. Author of The Four Habits of Healthy Families, find her on Twitter @Healthgal1103 and on Facebook @TheHealthGal. Check “Daily Health News” at Her personal mantra? “Fix it first with food, fitness, and lifestyle.”