Biotin: Benefits and Side Effects

Medically Reviewed by Zilpah Sheikh, MD on March 31, 2024
5 min read

Biotin is a B-complex vitamin that helps your body break down food into energy. You can get it from eating meats, eggs, fish, seeds, nuts, and some vegetables, or by taking a daily supplement.

The name “biotin” comes from the Greek word “biotos,” which means “sustenance” or “life-giving.”

Biotin, also known as vitamin B7, supports many parts of your body, including your nervous system, liver, eyes, hair, and skin. It helps the enzymes in your body carry out their jobs and keeps cells working as they should.

Some of its possible health benefits include:

Diabetes management

Studies show that biotin supplements may help manage symptoms of diabetes. It might help reduce blood sugar levels, total cholesterol, and blood fats in some people with diabetes. But it doesn't have much effect on insulin levels.

Plus, B vitamins are important for your brain and nervous system, which could help with neurological symptoms of diabetes, such as neuropathy (nerve damage). We need more research on this, though.

Biotin for hair

Some people have turned to biotin for longer, healthier hair. Research suggests that biotin supplements may benefit people with biotin deficiency or certain medical conditions affecting hair growth, such as alopecia. But there's a lack of evidence to show biotin works to grow hair in people without these conditions.

Nail health

As with hair, there's not enough scientific proof that biotin will give you longer, stronger nails unless you have a health condition that affects them.

Biotin for skin

Researchers have looked at the role of biotin in various skin conditions. They've linked a shortage of the vitamin to dermatitis, acne scarring, and other skin problems, but they need to do more research into how biotin levels affect your skin.

Prenatal care

Biotin is necessary for a healthy pregnancy. Studies show that about a third of pregnant women in the U.S. have mild biotin deficiencies, but we need more research to understand why.

During pregnancy, make sure to eat foods rich in biotin or talk to your doctor about taking a biotin supplement.

Nerve health

Biotin is thought to help nerves recover from damage, especially in people with progressive diseases, such as multiple sclerosis. But recent studies don't show any long-term benefits of taking high doses of biotin for nerve health.

Biotin tablets

You can take biotin as a multivitamin, B-vitamin complex, or individual supplement. They usually come in 10-microgram, 50-microgram, and 100-microgram tablets.

Biotin dosage

The amount of biotin you need daily depends on your age and gender. The FDA says adults need 30 micrograms daily. If you're nursing, you need 35 micrograms every day.

If you think you're not getting enough biotin in your diet, talk to your doctor about taking a daily supplement.

Biotin is a water-soluble vitamin, which means your body can't store it they way it stores fat-soluble vitamins. Instead, you have to replace it daily. Bacteria in your gut can create biotin, though researchers aren't sure what role this plays in your overall biotin levels.

Foods high in biotin include:

Beef liver. Just 3 ounces of cooked liver has 30.8 micrograms, which is 100% of your daily value.

Eggs, especially egg yolks. One cooked egg has 10 micrograms of biotin.

Milk. One cup of 2% milk has 0.3 micrograms of biotin. Milk also contributes to bone and teeth health, and it is a good source of protein, calcium, phosphorous, potassium, and vitamin D.

Bananas. One serving (half a cup) of banana has 0.2 micrograms of biotin. Bananas also have vitamin B6, vitamin C, and the minerals manganese, potassium, and magnesium.

Nuts and seeds have biotin, but how much you get depends. For instance, a quarter-cup of roasted almonds has 1.5 micrograms, but just six walnut halves have 9.5 micrograms. A quarter-cup of roasted sunflower seeds has 2.6 micrograms of biotin, more than the amount present in any other seed.

Pork chops. A 3-ounce serving of pork chops has 3.8 micrograms of biotin.

Salmon. A 3-ounce serving of cooked salmon has 5 micrograms of biotin, about 17% of your daily value.

Sweet potatoes have 2.4 micrograms of biotin in half a cup, about 8% of your daily value of biotin.

Mushrooms have biotin, too. A 100-gram serving of portabella mushrooms (a little more than 1 cup) contains 11.1 micrograms.

It's very rare to have a biotin deficiency, especially when you're healthy and eat a well-balanced diet. But there are symptoms if you're low on biotin, and they usually show up slowly. 

Biotin deficiency symptoms

Biotin deficiency symptoms can include: 

  • Hair loss (alopecia)
  • A red rash around your eyes, nose, mouth, and genital area
  • Brittle nails
  • Depression
  • Lethargy (lack of energy)
  • Hallucinations
  • Numbness of your extremities (hands or feet)
  • Seizures

Research suggests that taking biotin supplements, even in high doses, has very little risk.

Because biotin is water-soluble, your body flushes out any amount it doesn't need through your urine. But if you take too much, it could interact with other medicines you take or produce incorrect results on lab tests. Always tell your doctor about any dietary supplements you take.

Biotin, a B-complex vitamin found in foods like meats, eggs, fish, nuts, and some vegetables or in supplement form, helps to convert food into energy. It also supports various parts of your body, like the nervous system, liver, eyes, hair, and skin. While it may help manage diabetes symptoms and aid in prenatal care and nerve health, evidence of it improving hair, skin, or nails in those without deficiencies is limited. Foods rich in biotin include beef liver, eggs, milk, bananas, nuts, seeds, pork chops, salmon, sweet potatoes, and mushrooms.