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Biotin for Hair Loss
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on June 7, 2024

With all the research on diet and vitamin intake, the market for supplements that claim to treat the loss of hair continues to grow. Vitamin supplementation is one of the most popular ways to combat the loss of hair.

The global vitamins for hair growth industry doesn’t seem to be slowing down. It’s predicted to reach $196.56 billion by 2028 [1]. Biotin has exploded in popularity, with nearly every retailer selling multiple different versions.

The global biotin market is predicted to reach the dizzy heights of $2.4 billion by 2028. Many consumers take vitamin supplements as part of a healthy lifestyle.

So do biotin supplements work for hair loss, or for stimulating hair growth? In this article, you’ll learn:

  • How biotin works
  • Biotin’s efficacy as a treatment for hair loss and growth
  • Which foods are rich in biotin.
Table of Contents

What is biotin?

Biotin, also known as Vitamin B7 or Vitamin H, is a water-soluble vitamin in the Vitamin B family. It’s crucial for a lot of bodily functions and processes. 

Biotin helps the body convert food into energy, and it’s essential for the health of your skin, eyes, liver, and the correct functioning of your nervous system in addition to the support of healthy hair growth.

Biotin is also essential for pregnant women, as it helps the baby grow. It’s needed in small amounts, which helps your body create fatty acids.

How does biotin work?

Biotin plays an important role in keratin production. Keratin is the main protein in hair and nails, and biotin may improve the keratin infrastructure within our bodies. There is evidence that biotin deficiencies cause thinning hair and brittle nails [3].

Therefore, biotin is touted by supplement brands and on social media as a miracle cure for all four main types of hair loss:

Biotin isn’t just advertised as a hair growth supplement, either. Thousands of shampoos and conditioners are enriched with biotin, and marketed as products which will support healthy hair growth by giving you thicker, stronger hair that grows at a faster rate.

Despite many products and dietary supplements being marketed to women, male pattern baldness can be associated with a lack of biotin. Female pattern baldness is linked with low levels of vitamin D. (17)

Biotin supplements available online generally advocate for a dosage of between 2,000 and 5,000 mcg of biotin, to combat hair loss and promote hair growth. The Department of Health and Social Care advises taking 0.9 mcg of biotin or less per day, as there’s not enough evidence regarding taking high doses of biotin [4]. Find out which products to take in our guide about the best biotin products for hair growth.

Clinical research & evidence regarding biotin for hair health

A study from 2017 reviewed the use of biotin to treat hair falling out. They found 18 cases where biotin treatment improved the condition of the subjects’ hair and nails, but all of the patients had existing biotin deficiencies [5].

They concluded that if the patient didn’t suffer from a biotin deficiency but rather from a condition like uncombable hair syndrome [6], biotin supplementation could help combat hair loss. However, diseases like this are very rare in the general population.

Study on over-the-counter hair loss products

In another study of over-the-counter hair loss products, researchers found products containing biotin were generally ineffective [7]. While they concluded that it’s important to consume your recommended daily allowance of biotin for healthy hair, the only treatment for hair loss with proven efficacy in the study was Minoxidil. Ineffective treatments can cost as much as $1,200 per year.

Diffuse pattern hair loss study

One study looked at patients with diffuse pattern hair loss. Though this was a small study (just 50 patients), the findings were promising. Instead of supplementing biotin orally, they injected the patients with a mixture of biotin and dexpanthenol (a derivative of pantothenic acid). Hair fall count and total hair density were significantly improved in a 6-week treatment [8].

Biotin and telogen effluvium

2022 research focused on post-Covid-19 telogen effluvium concluded that hair growth improvements are only seen in patients who suffer from a biotin deficiency in the first place [9].

2021 statistics

Looking at statistics from 2021, we can see that biotin is in the middle of prescribed medications for hair loss. Though it’s not one of the top medications (that’s Finasteride, prescribed in 69.1% of cases), a biotin supplement is still prescribed in nearly 30% of cases.

Chart of medications prescribed by ISHRS for hair growth

What are the symptoms of a Biotin deficiency?

How do you know if you have a biotin deficiency? The symptoms are pretty varied, but include:

  • Dry eyes
  • Dry or scaly skin
  • Red rashes
  • Thinning hair
  • Brittle nails
  • Fatigue
  • Nausea
  • Prickling in the hands or feet.

The good news is that you’re unlikely to suffer from a deficiency unless you fit into one of the below groups.

Who is likely to have a biotin deficiency?

As well as coming from food intake, biotin is produced in the gut by intestinal bacteria. If you suffer from an Inflammatory Bowel Disease such as Crohn’s or Ulcerative Colitis you may be more at risk [10].

Chronic alcohol users and smokers (especially women) may suffer from biotin deficiencies. Something that isn’t as commonly known is the effect of eating egg whites on biotin intake. If you’re prone to eating lots of raw egg whites, a glycoprotein called avidin binds to the biotin in your gut. It affects the way biotin is absorbed.

Restrictive diets

Long-term dieting can also be a cause. Crash diets like intermittent fasting means hair may not grow, and a restrictive diet can cause nutrient deficiencies. The popular ketogenic diet, which involves eating a diet that’s low in carbohydrates and high in fat, has caused biotin deficiency in mice [11].

 Medications that cause biotin deficiency

Certain medications can cause biotin deficiencies. This study [12] of one patient looked at valproate use, a medication that treats epilepsy and bipolar disorder. They found that after taking 10,000 mcg of biotin daily for three months, the patient’s severe hair loss was completely reversed.

This singular study shouldn’t be taken as definitive proof, but it is known that antiepileptic medications such as carbamazepine, phenytoin, and phenobarbital can also cause biotin deficiency [13].

Biotinidase Deficiency (BTD)

Biotinidase Deficiency (BTD) is an inherited condition. Biotinidase is an enzyme that assists in recycling biotin, so it can be used by the body. Without biotinidase, biotin becomes depleted from cells, leading to a deficiency.

Many countries screen for BTD when an infant is born. It’s important to test for this condition as it can be very serious without treatment [14].

If you fit into one of the above categories and you want to know why your hair is falling out, it could be an idea to get tested and rule out a biotin deficiency as the cause.

What are the side effects of taking too much biotin?

Side effects of over-supplementation of biotin include the following:

  • Insomnia
  • Digestive issues
  • Problems with insulin release
  • Unsightly rashes.

There is anecdotal evidence that excess biotin can cause cystic acne. This may be because the body uses the same pathways to absorb biotin as it does to absorb vitamin B5, which fights acne (15).

The loss of hair can have a negative effect on self-esteem, so if you’re taking biotin for hair growth, be mindful of the possible side effects of acne. Acne can have a bad effect on your mental health.

False lab results are another side effect of biotin supplementation. They are a particularly prevalent side effect when being tested for thyroid conditions. It’s something to watch out for if you’re being treated for thyroid conditions, or suspect you may suffer from a related disease.

Biotin-rich foods 

The best way of taking in vitamins is through your diet, rather than supplementation. Biotin deficiencies are nearly unheard of in people without underlying health conditions who eat a balanced diet.

Nuts and seeds provide a great vegan source of biotin, as well as unsaturated fats. Sweet potatoes, avocados, and bananas all provide biotin in varying amounts. According to the Food and Nutrition Board of the Institute of Medicine, the recommended daily adequate intake (AI) is 30 micrograms for adults of 19 and above.

If you’re a vegetarian, egg yolks are an excellent source of biotin, protein and iron. A 50-gram egg has 10 mcg of biotin. Just make sure you cook the egg properly. For meat eaters, foods like liver and meats in general offer a high concentration of biotin. 75 grams of liver provides 31 mcg of biotin, which is your entire daily allowance.

So, does biotin work to aid hair growth?

Larger studies are needed to determine biotin’s efficacy in treating hair loss in non-deficient individuals. Looking at all the research, it’s probably not worth taking biotin supplements unless you have a very restricted diet, or you have symptoms of a biotin deficiency. It’s unlikely to deliver long, luscious locks or help your hair grow back after balding.

In fact, this article in the Journal for the American Academy of Dermatology went even further. They called the growing trend for biotin supplementation ‘alarming,’ considering that up to 20% of Americans weren’t disclosing the supplementation to their physicians [16].

Visit your doctor and ask for a blood test if you’re worried about any vitamin deficiencies. If you’re pregnant, your vitamin needs will change. It’s always worth checking with a doctor or nurse if you need to take additional vitamins.

Plus, be careful with biotin supplementation for hair growth or loss if you’re undergoing medical treatment, as it can interfere with test results.

Hair loss is more common than you might think. We offer a range of treatments for patients suffering from the loss of hair. Our Harley Street Hair Clinic has helped 10,000+ patients and has over 45 years of experience.

Contact us today to speak to a dedicated hair loss specialist about the hair restoration services we can provide for you.

Biotin for Hair Loss, Wimpole Clinic

Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on June 7, 2024
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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