What Happens If You Take Too Much Biotin

Photographed by Megan Madden.
For those of us who spend more time than we’d like to admit hanging out in the vitamin aisle of our local pharmacy, biotin is a staple. The supplement has made a name for itself in the beauty sphere, thanks to some small studies that found it to be a hero for healthy hair, nails, and skin. Celebrities like Kylie Jenner and Vanessa Hudgens have endorsed gummies boasting biotin benefits like SugarBearHair Gummy Hair Vitamins on Instagram.
However, nutritionists and experts think these aesthetic promises are oversold, and note that taking too much biotin can lead to the misdiagnosis of other health issues.
“I personally think that biotin supplements have been made popular because of the ‘beauty promise,’” says Marisa Moore, RDN. “It’s well established that the signs of a biotin deficiency include brittle nails, skin rashes and hair loss. So, supplements are often advertised as a way to boost hair, skin and nail growth. But we need more evidence to determine whether taking biotin without a deficiency will actually deliver those benefits.”
For the record, The National Institutes of Health says the beauty-related claims “are supported, at best, by only a few case reports and small studies.” There are several things to think about before you pop the pill promising you shiny hair straight out of a Keeping up with the Kardashians episode.
So, what is biotin anyway?
Biotin belongs to a class of B-vitamins. “It’s an essential nutrient that plays key roles in metabolism, gene regulation, and cell signalling,” according to Wendy Lopez, MS, RD, CDE, co-founder of Food Heaven Made Easy.
Should You Be Taking A Biotin Supplement?
Probably not. You should be getting the OK from your doctor before taking any supplement, and biotin deficiency is rare. So most doctors won’t recommend it. There are some people who might need more biotin than others, though. For example, if you’re constantly consuming alcohol, it can negatively impact the way you absorb the vitamin. If you’re pregnant or breastfeeding, you also might need more than the average person.
If you do happen to be riding in the small boat of people who need this supplement, be sure to do your research, and make sure it’s gone through independent lab testing to ensure that what’s on the label is present and active in the bottle, Moore says.
If I don’t take a supplement how will I get biotin?
You should be getting some biotin in your system — but you can save your money on supplements because it's already in your food.
“Whenever possible, you want to always aim to get your nutrients from foods versus supplements,” Lopez says. “When consumed through food, you’re getting a number of other nutrients… For example, by eating almonds you get biotin, but you also get fibre, protein, and polyunsaturated fats. Same goes for sweet potatoes. You’re getting the biotin, but you’re also getting beta-carotene, anthocyanins, and a number of vitamins and minerals.”
Other foods that naturally have biotin in them include organ meats, eggs, fish, meat, seeds, nuts, and certain vegetables, Lopez says.
What Happens if I Take Too Much Biotin?
Let’s say you’re frugal, and can’t stand the idea of wasting the remaining biotin supplements you bought, even armed with this knowledge. (Or maybe you just really like the taste of the gummies!) It’s probably safe to finish out your remaining vial.
“It is not necessarily dangerous,” says Michelle Allison, RD, citing the lack of evidence showing humans have an upper limit on how much they can take. That said, taking more biotin than you need can change your blood levels and cause you to have anomalous results on standard blood tests. The U.S. Food and Drug Administration even put out a warning in 2017 stating that the vitamin could interfere with lab tests.
“The issue with supplementing beyond the recommended intake is that it can affect other lab results, leading to misdiagnosis of medical conditions,” Lopez explains. “Taking as little as 10mg each day of biotin has shown to interfere with thyroid functioning tests, and one study specifically saw falsely decreased levels of thyroid stimulating hormone after supplementation, which could lead to a misdiagnosis of thyrotoxicosis.”
In layman’s terms: You should absolutely tell your doctor about all of the supplements that you’re taking, or they could miss something. At a check-up, it can be tempting to tell your nurse “I take a multivitamin” and call it a day, assuming that covers your bases. But details pay off — especially when your health is involved.
It’s important to think about you individual needs and research what you’re putting into your body before you hit the vitamin aisle — no matter what Kylie Jenner is doing.

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