What is biotin? 

Biotin, also known as Vitamin H or Vitamin B7, is a water-soluble vitamin that plays an essential role in various metabolic processes in the body. It is involved in the metabolism of carbohydrates, fats, and amino acids, and is necessary for the formation of fatty acids and glucose. Biotin is also important for the maintenance of healthy skin, hair, and nails, as well as the nervous system.

How does it work?

Biotin works by acting as a coenzyme that helps in the transfer of carbon dioxide in the body. It helps in the production of glucose from non-carbohydrate sources and the synthesis of fatty acids and amino acids.

What is the active ingredient that makes it work?

The active ingredient in biotin is biotin itself.

What forms does it come in?

Biotin is available in several forms, including oral supplements in the form of tablets, capsules and liquids, as well as topical creams and shampoos.

When was it first used for medicinal purposes?

The use of biotin as a dietary supplement for medicinal purposes was first reported in the 1940s.

What if I have an imbalance or deficiency?

An imbalance or deficiency in biotin can lead to symptoms such as hair loss, dry skin, and brittle nails. In severe cases, a deficiency can lead to neurological symptoms such as depression, fatigue, and insomnia.

What does Biotin help with?

Biotin is a B vitamin. It dissolves in water, so your body does not store much of it. Your body is well known to use biotin to turn food into energy, and it is often sold for hair, skin, and nails.

The library grades biotin C overall. Most of the human studies are small, and some had no placebo group. The clearest results came in people who were low in biotin to start with.

• Brittle nails that split or peel
  Early evidence — two small open studies with no placebo group. In one study of 45 people with brittle nails, the dose was 2.5 mg of biotin a day. About 9 in 10 reported firmer nails. A second small study of 32 people used the same dose, and 8 showed thicker nails.
  Evidence grade C · Traditional tier T0
• Hair loss and scaly rash caused by a proven biotin shortage
  Early evidence — case reports and small case series in people with confirmed deficiency. In case reports, people low in biotin had hair loss and a scaly rash. These signs eased after they took biotin. The reports had no control group, so they are weak evidence.
  Evidence grade C · Traditional tier T0
• Blood sugar in type 2 diabetes
  Early evidence — one randomised trial of 348 people, biotin combined with chromium. In a trial of 348 adults with type 2 diabetes, one group took a daily combined pill. It held 2 mg biotin plus 600 mcg chromium picolinate, taken for 90 days. Their HbA1c, a long-term blood sugar marker, fell more than with placebo. Biotin alone was not tested, so the chromium may explain the change.
  Evidence grade C · Traditional tier T0
• Progressive multiple sclerosis
  Evidence doesn't support this — one positive 154-person trial and one larger 642-person trial that found nothing. In the MS-SPI trial, 154 people with progressive MS took 300 mg of biotin a day. Slightly more of them improved than on placebo. A larger trial, SPI2, enrolled 642 people and found no benefit. The two trials conflict.
  Evidence grade D · Traditional tier T0
• Thicker or faster-growing hair when your biotin level is normal
  Not yet tested in people — no trial in people with normal biotin levels; case reports only. A 2017 review in Skin Appendage Disorders found 18 reported cases of biotin helping hair or nails. Every one of those people had an underlying deficiency. No human trial on file has tested biotin for thinning hair in people who are not deficient.
  Evidence grade insufficient · Traditional tier T0
• Low energy and tiredness
  Not yet tested in people — general nutrition science only; no human trial of supplements for fatigue on file. Biotin is well established to help the body turn food into energy. That is basic nutrition science, not a trial of biotin pills. No human study on file tested whether extra biotin lifts energy in people who already get enough.
  Evidence grade insufficient · Traditional tier T0

What Biotin has not been shown to do

• Biotin has not been shown to grow thicker or faster hair in people whose biotin levels are normal.
• Biotin has not been shown to raise energy or cut tiredness in people who are not deficient.
• High-dose biotin was not shown to slow progressive MS in the larger of the two trials, which enrolled 642 people.
• Biotin alone has not been shown to lower blood sugar, since the 348-person trial paired it with chromium.

How to read this:

Each use gets its own grade, based on the studies behind that use. A means steady results from randomised human trials. B means at least one good human trial. C means small, mixed, or early human studies. D means the human evidence is weak or clashes. Insufficient means no human study on file. This page reports what studies found. It is not medical advice, and it is not a claim that biotin treats anything. One practical note: high-dose biotin can skew some lab blood tests, so tell your doctor if you take it. Talk with your own clinician before you start.

What can Biotin help prevent?

• Biotin deficiency in people whose intake or absorption is low — long-term anti-seizure medicines, prolonged antibiotics, or regularly eating raw egg white
• Return of symptoms in inherited biotinidase deficiency, under medical care
• Worsening of brittle nails in people already prone to nail fragility

Which foods are rich in it?

1. Eggs
2. Milk
3. Cheese
4. Salmon
5. Avocado
6. Almonds
7. Sweet potatoes
8. Peanuts
9. Bananas
10. Cauliflower

What are possible side effects?

Biotin is generally well-tolerated, but some people may experience the following side effects:

• Digestive issues such as bloating, cramping, and diarrhea
• Skin reactions such as itching or rash
• Allergic reactions

What’s the recommended daily dose?

The recommended daily dose of biotin for adult men and women is 30 micrograms.

How many days does it take to work?

The amount of time it takes for biotin to work may vary depending on the individual and the specific condition being treated. However, some people may notice improvement in symptoms within a few weeks of taking biotin supplements.

What time of day is best to take it?

Biotin can be taken at any time of day, with or without food.

Is it best to take it with or without food?

Biotin can be taken with or without food, but it is recommended to take it with a meal to increase its absorption.