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Biotin Benefits, Side Effects & Safety Information

Published: 13th May 2018. Last updated: 21th July 2019.

Luna Smithton

Editor & Fact Checker


Biotin is a B vitamin and an important enzyme in the body that helps the body metabolize macronutrients like fats, protein, and carbohydrates.

B Vitamins, especially Biotin, are needed to keep your hair, skin, eyes, liver, and nervous system healthy. Biotin is particularly needed during pregnancy because it contributes to healthy embryonic growth.

Biotin is a water-soluble vitamin, meaning that it isn’t stored in the body, and daily intake is necessary. Most people get enough Biotin from eating a healthy and balanced diet, but some people could develop Biotin deficiencies. For example, those who have health conditions impacting how the body absorbs nutrients, those taking certain medications that prevent vitamin absorption, people with intestinal problems or those who have been dieting for a long time.

Blood tests could show lower levels of Biotin, but this condition is typically identified by symptoms like thinning or brittle hair, red, scaly rashes on the face (i.e., around the eyes, nose, and mouth), and dry eyes. Other symptoms of Biotin deficiency are fatigue, depression, hallucinations, insomnia or difficulty sleeping, loss of appetite, nausea, and muscle pain. However, it is worth noting that the symptoms of Biotin deficiency could be similar to that of many other health disorders, making it difficult to diagnose.

Since Biotin plays a crucial role in our metabolism, some research suggests that low levels of Biotin could be hindering weight loss. If you do have a Biotin deficiency, supplementing your diet with this vitamin could improve metabolism.

The Potential Benefits of Biotin

Below we've listed everything we've found with any sort of credible scientific backing:

Biotin Could Boost Hair Growth and Reduce Hair Loss

Some studies suggest that Biotin supplements could prevent or stop hair loss – and there is strong evidence that Biotin deficiency causes hair loss. [1]

A study into the efficacy of Biotin showed that it could boost hair growth and reduce hair loss. Participants of the study (i.e., healthy women aged 21 to 75 with thinning hair) were randomized into two groups. Half were given an oral protein supplement containing Biotin, while the other half received a placebo treatment. The study lasted 180 days. [2]

The results showed that the supplement helped significantly boost hair growth in areas affected by hair loss, as well as helped reduce shedding.

Another study carried out in 2015 showed similar results, with an increased number of hair and decreased hair shedding in women after 90 days. [3]

Biotin Could Boost Metabolism and Aid Weight Loss

When trying to lose weight, it is important to make sure your body is functioning as efficiently as possible for weight loss. Biotin is a group B vitamin, and is essential for metabolizing fats, carbohydrates, and proteins. It plays a key role in the following processes:

  • Gluconeogenesis. Our bodies use energy from glucose – but only store enough glucose to last for a few hours. Gluconeogenesis allows for glucose production from other sources than carbs – for example, amino acids. Biotin helps initiate this process.
  • Fatty acid synthesis. Biotin plays a key role in assisting the enzymes that activate reactions which are important for the production of fatty acids.
  • The breakdown of amino acids. Biotin is involved in the metabolism of a few very important amino acids (including leucine).

While there isn’t any research suggesting that Biotin supplements could act as a weight loss pill, some studies do show a positive link between Biotin consumption and losing pounds.

A research study published in 2008 found that chromium picolinate and Biotin combination administered to overweight or obese patients with type 2 diabetes, improved their glycaemic control. [4]

Another study confirms that inadequate levels of Biotin could slow down metabolism, leading to digestive problems, fatigue – and weight gain. [5]

Therefore, if you’re aiming to lose weight, it may be worth finding out if you have a Biotin deficiency. If so, taking supplements with Biotin could boost your metabolism, and promote weight loss.

Biotin May Help Make Your Nails Stronger

There is also some evidence that Biotin could make brittle nails stronger.

A study published in 1989 showed that 91 percent of the 45 patients who took part had “firmer and harder fingernails” after taking an oral supplement of Biotin for 5 months. [6]

Another research study concluded that “brittle nail syndrome appears to abate with supplementation with a 2.5-mg dose of Biotin daily or a 10-mg dose of silicon daily”. [7]

Biotin Could Help Regulate Blood Sugar Levels

Some studies suggest that Biotin may help regulate blood glucose levels.

Biotin has been shown to play a role in regulating blood glucose levels in patients with type 2 diabetes. In this animal study carried out in 2012, supplementation of Biotin and chromium picolinate resulted in lower levels of circulating glucose, cortisol, and total cholesterol. [8]

Another study performed on animals suggests that Biotin could help prevent kidney damage in those with insulin-dependent type 1 diabetes. [9]

However, more research is needed to support these claims.

Biotin Supports Immune System

Biotin plays a key role in the development of white blood cells. It boosts the production of Th1 cytokines like IFN-γ and IL-1β – both essential in the immune response needed to fight viral and bacterial infections. [10]

Its deficiency has been linked to immune system impairments, and a higher risk of infections. [11]

Biotin Promotes Brain Function

Biotin is needed for myelin sheath formation: a fatty substance which forms around the nerves and facilitates nerve impulses. This suggests that its deficiency could delay the myelination process. [14]

Multiple sclerosis could cause myelin damage and loss. Some research suggests that Biotin may help limit or reverse sclerosis-related damage. [15]

Some studies actually show that high-dose Biotin treatment successfully reverses the progression of the disease – and improves multiple sclerosis symptoms. [16]

However, even though these studies sound promising, more research is needed to assess Biotin’s efficacy.

Biotin deficiency can cause many other neurological symptoms, such as lack of muscle coordination, seizures, hallucinations, learning disabilities, depression, and lethargy. Studies show that most of these can be effectively resolved with Biotin supplements. [17][18]

Biotin May Improve Skin Health

Biotin plays an important role in the synthesis and metabolism of the fatty acids (both critical for skin’s good health).

Research has linked Biotin deficiency to many skin conditions, including rashes, eczema, psoriasis, and dermatitis. Therefore it may improve skin conditions of those who are Biotin deficient. [19]

Which Foods Contain Biotin?

There are many Biotin-rich foods, such as:

  • Organ meats (e.g. kidney, liver)
  • Salmon
  • Egg yolk
  • Dairy (e.g. milk, cheese, yogurt)
  • Nuts (e.g. peanuts, almonds, pecans, and walnuts)
  • Nut butters
  • Seeds (e.g. sunflower seeds)
  • Soybeans and other legumes (e.g. green peas, chickpeas, lentils)
  • Yeast (both nutritional and brewer’s)
  • Cauliflower
  • Mushrooms
  • Fruit (e.g. bananas)
  • Whole grains and cereals

Various food processing techniques make Biotin inactive, so choose raw or less processed versions of these Biotin-rich foods.

Biotin Side Effects List

While Biotin has various health benefits, just like with any supplement, some side effects may occur.

While Biotin hasn’t been associated with any adverse side effects, there also hasn’t been enough research to determine the side effects of taking very high doses of it.

The most common side effects of Biotin are:

  • Nausea
  • Digestive issues
  • Skin rash

Note: these side effects are possible but may not be the typical user experience.


Biotin is an essential vitamin which is part of the vitamin B group. It is needed for the health of our skin, nails, hair, liver, as well as the functioning of our nervous system.

While most people get enough Biotin from their diet, some may develop Biotin deficiencies. Those who smoke, take medications or have a health condition which prevents Biotin absorption, are likely to need more Biotin.

Biotin has many health benefits and is also used by people as a supplement to help improve skin, nail and hair health, lower cholesterol, and to support metabolism. Some studies show that taking Biotin can help boost your metabolism. However, since most people get enough Biotin from their diet, it is important to consult a doctor before you start taking it to support your diet.

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