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Biotin for hair loss
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on August 24, 2022

Androgenetic alopecia is the most common cause of hair loss in both men and women. Also known as male pattern baldness and female pattern baldness, hair loss affects your confidence and self-esteem. It can have negative effects on your mental health, especially if you’re unable to discern the cause. Research over the last few years has posited a link between diet and lifestyle and hair loss. 

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

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 – available in capsule, tablet, soft gel and liquid form – 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 [2], as a large number of consumers look towards a healthier lifestyle, and ‘fixing’ issues like vitamin deficiencies.  

Does biotin work for hair loss, or for stimulating hair growth? In this article, we’ll look at exactly how biotin works, its efficacy as a treatment for hair loss and growth, the clinical research, and which foods are rich in biotin. 

What is biotin?

Biotin is a water-soluble B vitamin, also known as Vitamin B7. 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, hair, eyes, liver, and the correct functioning of your nervous system. 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.

Learn more about pregnancy and hair loss.

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: telogen effluvium, alopecia areata, male pattern baldness and female pattern baldness. 

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

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

Supplements available online generally advocate for a dosage of between 2,000 and 5,000 mcg of biotin, to combat hair loss and kickstart new 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]. 

Clinical research & evidence 

What does the clinical evidence say on the use of biotin? A study from 2017 did a comprehensive review on the use of biotin to treat hair falling out, looking at all the available literature. 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 did conclude 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. 

In another study of over the counter hair loss products available from online retailers, researchers found little efficacy from the products containing biotin [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

Additionally, the ineffective treatments such as biotin were expensive, costing as much as $1200 per year. One interesting 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 was significantly improved in a 6 week treatment [8].

Research has also been done into biotin’s role in combatting hair loss caused by Covid-19. This 2022 research focused on post-Covid-19 telogen effluvium, in a bid to educate patients about treatments for hair loss and hair growth that really work. This study also concluded that hair growth improvements are only seen in patients who suffer from a biotin deficiency in the first place [9].

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 – biotin is still prescribed in nearly 30% of cases.

Biotin for hair loss, Wimpole Clinic

Biotin deficiencies – symptoms 

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, and prickling in the hands or feet. The good news is, 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. 

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

Find out more about the ideal diet for healthy hair

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) 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. 

Side effects of biotin supplementation 

Side effects of over supplementation include insomnia, digestive issues, problems with insulin release, and unsightly rashes.

There is anecdotal evidence that too much 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). 

Hair loss 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. The recommended daily allowance 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. 


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. 

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 hair loss. Our Harley Street Hair Clinic has helped 10,000+ patients and has over 45 years of experience. 

Still unsure about treatment? Call us on 0207 935 1861 to speak to a dedicated specialist.


Biotin for hair loss, Wimpole Clinic


  1. The global vitamins and supplements market is anticipated to grow from $129.60 billion in 2021 to $196.56 billion in 2028 at a CAGR of 6.13% in the forecast period
  2. Biotin Supplements Market to Reach USD 3.4 Billion by 2028 | Consumer Preference Towards Dietary Supplements and Growing Number of Health-Conscious Customers across the Globe Drives the Market | Vantage Market Research
  3. Biotin
  4. B vitamins and folic acid 
  5. A Review of Biotin for Hair Loss 
  6. Uncombable hair syndrome
  7. A Comparative Study of Online Over-The-Counter Hair Loss Products 
  8. Efficacy of intramuscular injections of biotin and dexpanthenol in the treatment of diffuse hair loss: A randomized, double-blind controlled study comparing two brands
  9. Complementary Strategies to Promote Hair Regrowth in Post-COVID-19 Telogen Effluvium
  10. Micronutrient Deficiency in Inflammatory Bowel Diseases: Cause or Effect?
  11. Biotin deficiency 
  12. A Case Report of Biotin Treatment for Valproate Induced Hair Loss
  13. Biotin Deficiency
  14. Biotinidase Deficiency
  15. A Randomized, Double-Blind, Placebo-Controlled Study of a Novel Pantothenic Acid-Based Dietary Supplement in Subjects with Mild to Moderate Facial Acne
  16. Response to: “Rethinking biotin therapy for hair, nail and skin disorders.”
  17. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss


Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on August 24, 2022
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
Talk to a specialist ☎ 020 7935 1861.
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on August 24, 2022

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