7 Unexpected Side Effects Of Taking Biotin, According To Experts

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Biotin is a popular supplement for those who are looking to improve their skin or grow their hair and nails. But just as with any supplement, it's important to be aware of how it could negatively impact your body. There are a number of unexpected negative side effects of taking biotin, and it's good to be aware of them before you start a regimen. Not all these things will necessarily happen just because you take biotin, but before you begin ingesting the supplements, you should proceed with caution and always talk to your doctor about all possible side effects.

"Those with biotin deficiency may potentially benefit from biotin supplementation for their condition," Dr. Nesochi Okeke-Igbokwe tells Bustle. "It is generally deemed safe as long as you are taking the recommended dosage prescribed by your doctor. Biotin has grown in popularity though for generally healthy individuals trying to strengthen their nails and promote the growth of their hair. More scientific studies are really needed to confirm the efficacy of biotin for this purpose."

There are some studies that suggest that biotin can help with hair and nail growth, according to Mayo Clinic, but the vitamin can also come with some unwanted side effects. When in doubt, always consult with a physician before beginning a biotin regimen to be safe. Here are seven unexpected — and potentially dangerous — side effects of taking biotin, according to experts.

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Too much biotin can cause cystic acne that develops along the chin and jawline. This is because of the type of vitamin biotin is and how it is absorbed by the body. “Both biotin (Vitamin B7) and pantothenic acid (vitamin B5) are absorbed from our gastrointestinal system via the same receptors,” Dr. Yoram Harth, a board-certified dermatologist and medical director of MDacne, tells Bustle. “Thus, when taking an overload of biotin, the amount of vitamin B5, that is absorbed, decreases.” This Vitamin B5 is considered to be a strengthener for the epidermis, helping fight acne. The less of the vitamin that exists in your body, the more acne-prone you can become.

"Although this is not considered 'dangerous' it is a side effect that can impact your life — cystic acne can be painful — and self-esteem," Dr. Melanie Kingsley, dermatologist at IU Health, tells Bustle. Some other symptoms of cystic acne are increased whiteheads, blackheads, papules, pimples, nodules, and cystic lesions, according to Mayo Clinic.

Skewed Lab Results

Depending on your dosage, biotin may cause false-positives or false-negatives for different lab tests. "If you are taking very high levels of biotin, it may potentially skew the results of certain lab values such as cardiac troponins (a marker used to help diagnose a heart attack) and thyroid hormone studies," Dr. Okeke-Igbokwe says. "This may potentially contribute to a misdiagnosis. It is extremely important to always indicate to your doctor every medication you are taking, including any over the counter supplementation whenever you are getting blood work done." In order to make sure your lab tests are accurate and that you don’t get misdiagnosed, your doctor will often suggest you stop taking the vitamin before having any lab tests done. It’s difficult to determine how much time before your lab test you should stop taking biotin, but your doctor can help you figure out when.

Increased Blood Sugar Levels
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There’s been a lot of discussion around the way biotin can affect your blood sugar. Biotin can help lower blood sugar, but according to the University of Michigan, those taking insulin can face dangerously low blood sugar as a result of taking biotin, too. Experts have also reported that biotin can cause a slower release of insulin and increase of blood sugar levels, which is particularly important to diabetic patients or people with high blood pressure. "A slower release of insulin can lead to higher blood pressure, which can lead to clots or stroke (if not monitored closely)," Dr. Kingsley says. "Untreated high blood sugar can be dangerous for diabetic patients, possibly leading to a serious condition called ketoacidosis. Thus, diabetic patients or those with high blood pressure should be careful with biotin dosage to avoid complications."

Upset Stomach

Taking biotin may also wreak havoc on your digestive system. "Some people can experience stomach discomfort from taking biotin, including nausea, cramping, and diarrhea," Dr. Tania Elliott tells Bustle. Though these signs are already listed as possible side effects for the medicine, it’s still important to let your doctor or physician know if you experience any discomfort or pain. Sometimes these side effects can be indicative of your body reacting negatively to the biotin in more serious ways, and you may need to consider alternate vitamins or medications.

Skin Rash
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Negative skin reactions can also occur as a result of taking biotin. "There have been instances of severe skin rashes from biotin, where blood vessels can become inflamed because the immune system perceives the biotin as something foreign," Dr. Elliott says. Sometimes these skin rashes happen because of an allergic reaction to the vitamin but other times it can be a direct reaction to having a larger dose of biotin in the body. You can combat this by talking to your doctor about starting biotin in smaller doses, so your body can get used to the vitamin before you use it more regularly.

Allergic Reaction

This is more common in those with an allergy to Vitamin B12 or cobalt. That said, an allergic reaction to biotin will often include nausea, a rash, or swelling of the throat and face. While manageable, allergic reactions can become very dangerous if not addressed by a medical professional. To avoid this, it can be a good idea to stop using biotin in large doses to see how your body reacts, or even check with your doctor or physician to see if you might have allergic tendencies toward biotin before any use.

Interactions With Medications
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Biotin can cause interactions with medications, including those for cholesterol, diabetes, and anticonvulsants, and can lower their effectiveness. "Any interaction with a medication can potentially be dangerous to a patient, which is why it is very important to discuss all of your medications and supplements with your doctor," Dr. Kingsley says.

Many people take biotin with no issue, but it's always important to talk to your doctor if you're experiencing anything out of the ordinary. That way, even if you want to continue using the vitamin, your doctor can provide you with safer, alternate ways to take biotin.

This post was originally published on May 25, 2018. It was updated on June 18, 2019. Additional reporting by Syeda Saad.