The Under-The-Radar Potential Side Effects You Need To Know If You Take Biotin


  • Unless you have a deficiency, you don’t need to take a biotin supplement.
  • There is limited evidence taking biotin can improve hair, skin, or nail health.
  • Taking too much biotin can have negative side effects.

Among the thousands of dietary supplements on the market, it can be difficult to decide which ones are right for you. Some can offer real health benefits, while others are just unnecessary despite the hype. 

The latest supplement fascination on social media and beyond is biotin, or vitamin B7, which is purported to improve hair, skin, and nail health. But despite its popularity, physicians are rarely inclined to recommend this in-vogue supplement.

Why? Evidence that biotin supplements can actually improve hair, skin, or nails is lacking. Since the supplements industry is more loosely regulated than prescription drugs, not much research is available.

We do know that at best, too much biotin can be unnecessary but harmless, while at worst, it can be problematic for your health.

Unless It’s Doctor-Prescribed, You Probably Don’t Need Biotin

Biotin is important because it helps break down fats, carbohydrates, and protein in our food. It also plays a role in helping your body produce keratin, a type of protein that is found in our hair, skin, and nails.

It is likely this latter bit that has led to the notion that taking biotin supplements can make nails stronger, support hair growth, and keep skin looking young. This is misleading for a few reasons.

To start, studies show taking a biotin supplement is only effective for those with an actual deficiency, which is quite rare.

You likely already consume plenty of biotin in your diet anyway. In fact, it’s difficult to avoid biotin throughout the day because it’s so readily available in many foods including eggs, fish, meat, seeds, nuts, and vegetables. Biotin is also found in many multivitamins.

The daily biotin requirement for adults 19 years or older is 30 micrograms (mcg). That’s substantially less than common supplements on the market that boasts biotin levels of 10,000 mcg (or even more).

Moreover, there is very limited evidence that popping a biotin capsule every day will help you grow thicker, stronger hair.

One study from 2012 showed that women who took a supplement that contained biotin reported a visible increase in hair thickness and growth compared to a placebo group, but there were multiple caveats with this research.

In addition to being a small pool of participants, the supplements given also contained ingredients such as zinc and iron, which could have played just as much if not more of a role in the, again, self-reported results. It was also noted that participants could have had a nutrient deficiency that was inadvertently corrected during the study.

Other research has shown more promising results for biotin supplements aiding in preventing hair loss, but this seemed to be in individuals who had a deficiency.

The Potential Cons Of Taking Too Much Biotin

While biotin supplements are usually unnecessary, high doses of biotin are not typically toxic given that it is water-soluble (aka excess biotin will just end up in your urine). But taking higher doses is not without risk. 

Excessive biotin in the bloodstream can interfere with lab test results, leading to misdiagnoses or missed diagnoses.

An excessive amount of biotin can cause a false negative on a blood test that measures troponin levels, used to diagnose heart attacks and strains. Too much biotin can also hamper blood tests that measure thyroid hormones, reproductive hormones, and vitamin D levels. 

Other documented symptoms of taking too much biotin include insomnia, excessive thirst, and excessive urination.

Moreover, there have been self-reported claims that taking too much biotin can cause you to break out, but there are no scientific studies to back that up.

At the end of the day, chances are that the biotin gummy you’re taking is just money flushed down the toilet (literally). If you suspect you have a biotin deficiency, which can include symptoms such as hair loss, extremely dry skin, dry eyes, loss of appetite, or a swollen tongue, it’s always best to consult with a doctor first.

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