Are there side effects to taking biotin?

March 05, 2020

Are there side effects to taking biotin?

Are there side effects to taking biotin?

Treating a biotin deficiency with a supplement has become popular in the past few years. Biotin or vitamin H or B7 is a water-soluble vitamin that plays a vital role in energy conversion. As one of the B complex vitamins, it aids energy creation by helping to form glucose (sugar) and fatty acids. Your body uses glucose and fatty acids as fuel. Also, biotin assists the dissolving of fat and aids carbohydrate and amino acid metabolization in the body.

Many foods and beverages, such as salmon, nuts, carrots, and milk, contain biotin. But if you're deficient in this critical vitamin, you can take a biotin supplement. For adolescents and adults, the daily dose is usually between 30 to 100 micrograms. If you're taking biotin, you might be worried about the possible side effects.

Adverse side effects of taking biotin

According to the Mayo Clinic, no adverse side effects for up to 10 micrograms per day have been reported (1). If prescribed by a doctor or through a healthy balanced diet, side effects are not usually present.  Several studies have shown that biotin poses no risk when taken at higher doses, too. (2)

The reason is that the body removes excess biotin through urine and feces. So even if you take a large dose, your body can naturally expel the excess. The body's ability to flush the biotin makes an overdose highly unlikely. Still, it’s not wise to take biotin in an improper dose because it can cause some minor adverse side effects. (3)

Incorrect lab test results

In some cases, biotin in extremely high doses can cause false lab results. If you have a diagnostic test to measure hormones, such as thyroid hormone or vitamin D, the biotin may interfere with the measurement. When this happens, your levels may appear falsely normal or high.

According to the National Health Institute, false lab results indicated Graves disease or hyperthyroidism in people supplementing with biotin in the amount of 10-300 mg per day. The incorrect results even occurred for six children taking high biotin doses. (4) Biotin supplementation has also interfered with thyroid function tests with as little as one 10 mg dose. (5)

The Food and Drug Administration (FDA) recommends that healthcare professionals determine if their patients are taking biotin before having a laboratory test to measure hormones. Before undergoing specific tests, the patient should consider ending biotin supplementation.

Interactions with medications

Men and women taking biotin may need to worry about how the supplement interacts with certain medications. Also, some medicines can affect biotin levels. If you're taking medications, it's essential to discuss biotin supplementation with your doctor. 

For those with epilepsy and taking anticonvulsants, one small study of 264 people showed low biotin levels. (6) The men and women in the study took carbamazepine, primidone, and phenobarbital to control seizures. Other small studies have found similar results. (7) The reason for the medication interference isn't apparent, but scientists think anticonvulsants limit biotin absorption in the gut. The result is an increase in biotin catabolism or the breakdown of molecules into smaller ones.

Positive side effects of taking biotin

Biotin is essential for giving your body the fuel it needs to tackle everyday life. Like all vitamins and minerals, it's necessary for keeping your body in good shape. It also can help with critical medical concerns.

Blood sugar regulation

Blood sugar regulation or glucose control is important to prevent diseases, such as diabetes. In a double-blind study with 447 participants, biotin taken with chromium picolinate improved blood sugar regulation.

The men and women in the study were overweight to obese and had type 2 diabetes. (8) Taking a biotin supplement for those with diabetes may help with glycemic control.

Low blood sugar

Low blood sugar or hypoglycemia happens when the body doesn’t have enough sugar to convert into energy. It can arise for different reasons, including skipping meals, eating too little, exercising too much, or a reaction from certain medications. When you eat food, biotin helps convert the carbohydrates into energy. Insulin, produced in the pancreas, helps aid this process, too.


Without enough glucose, your body cannot perform daily functions. If this happens, you may have low energy, blurry vision, dizziness, and headaches. Biotin can help raise blood sugar levels and optimize bodily functions. (9)

Improves hair and nails

One of the main reasons biotin has become popular in the past few years is because some people believe it strengthens hair and improves nails. While research is still in its early stages, lots of anecdotal evidence and a few studies suggest that biotin works.

Your hair, skin, and nails have a simple protein called keratin. Biotin aids your body's keratin make-up. In a 3-month study, women with thinning hair took biotin to promote hair growth. The 60 women in the clinical received a marine protein supplement (MPS) that included biotin or a placebo. After the completion, the results showed a significant amount of hair regeneration for those taking MPS. (10)

Prevents high cholesterol

According to the American Heart Association, high cholesterol or hyperlipidemia is when your blood has too many lipids (fats). (11) Eating a healthy diet, receiving regular exercise, and quitting smoking are all ways to lower cholesterol. Another agent for preventing high cholesterol may be with biotin supplements. (12)

If you're experiencing a biotin deficiency, taking a supplement may improve your life. The adverse side effects aren't common but can happen under certain conditions. Speak to your healthcare professional about taking a biotin supplement. It may do this by lowering the bad cholesterol in the blood.