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  • Rajani Katta MD

Biotin: The Hidden Dangers

Updated: Aug 16, 2020

Warning: Biotin, a popular nail supplement, may interfere with lab tests for heart attacks and thyroid function.

Before you reach for that supplement bottle of biotin, make sure you know about this recent FDA warning. Biotin may interfere with laboratory tests, including tests for heart attacks and thyroid function.

Biotin supplements have become popular for those with brittle nails, but are the subject of a recent FDA warning


Biotin is a popular supplement for nail health, but we don't have research for its use in skin and hair

While there haven't been many studies, several have shown that taking biotin supplements may improve nail hardness and nail thickness in some people with brittle nails.

For skin and hair health, though, we just don't know. If you don't have a biotin deficiency [and the vast majority of people do not], then we just don't know whether taking extra biotin will help your skin and hair.


Some people may have a biotin deficiency, but this isn't common. This may occur due to genetics, GI conditions, or raw egg white consumption.

Are you likely to have a biotin deficiency? Probably not.

Some people have genetic conditions that make them prone to biotin deficiencies. These individuals may develop hair loss and skin inflammation, along with other symptoms.

Some people may also develop a biotin deficiency. That's not common, but it's been seen in some individuals with certain gastrointestinal conditions. It's also been seen in individuals who eat a lot of raw egg whites.

If you have a known biotin deficiency, then taking supplements to correct that deficiency may help with your skin and hair symptoms.

If you don't have a deficiency, though (and the vast majority of people in the US don't), then it's unclear if taking extra biotin will help your skin and hair. That research just hasn't been done.

What we do know is that that extra dose of biotin may interfere with some important laboratory tests.

It is unknown if taking extra biotin (if you don't have a deficiency) will do anything to strengthen your skin and hair


Biotin supplements may interfere with lab tests used to diagnose heart attacks

The FDA recently issued a warning that taking biotin supplements may interfere with certain laboratory tests. One of these tests is a very important one: troponin.

High troponin levels are one of the tests used to make a diagnosis of a heart attack. Unfortunately, taking biotin may lead to a falsely low level of troponin. This means that if you're having a heart attack and taking biotin, you may not be diagnosed correctly.

Biotin supplements can interfere with the tests used to diagnose heart attacks and thyroid disease

These supplements can interfere with other laboratory tests also. Biotin supplements in one study of healthy adults were shown to interfere with levels of TSH and thyroid hormone, as well as other lab tests. In fact, the FDA states that patient may have to wait eight hours, or at higher doses even three days, before undergoing certain laboratory tests.

Always tell your physician about any supplements that you're taking. For biotin, it's especially important to tell your physician before lab tests

The bottom line: While it's possible that biotin supplements may improve brittle nails for some people (based on the results of a few studies), biotin just hasn't been studied for hair loss or skin health. And biotin is now known to result in an unexpected side effect: it may interfere with certain lab tests. If you're taking biotin supplements, make sure you tell your physician before you undergo any laboratory testing.

Dr. Rajani Katta is the author of Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet. To receive future updates on preventive dermatology and the role of diet, sign up here.

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