Biotin for Hair Growth

Can Taking Biotin Lengthen Your Locks?

hair growth
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Biotin is a B-complex vitamin often recommended for hair growth. Since biotin deficiency can lead to thinning of the hair, proponents claim that taking biotin supplements or washing your hair with biotin-enriched shampoo can thicken the hair and stimulate hair regrowth.

Found naturally in foods such as milk, egg yolk, and bananas, biotin in supplement form is sometimes used to promote healthy nail growth or as a treatment for brittle nails, biotin deficiency, diabetes, seborrheic dermatitis, and mild depression.

Related: Biotin for Nail Growth

Research on Biotin for Hair Growth

There isn't enough evidence to rate biotin's effectiveness in treatment of hair loss, according to the National Institutes of Health (NIH). However, there's some evidence that biotin may benefit children with alopecia areata. For instance, a 1999 study published in Pediatric Dermatology found that taking supplements containing both zinc and biotin while topically applying a cream made with clobetasol propionate (a synthetic steroid hormone) may help reduce the hair loss associated with childhood alopecia areata.

Manufacturers claim that shampoo containing biotin can thicken hair, increase fullness, and add shine. Despite these claims, there are no scientific studies to show that biotin shampoo can benefit the hair.

Dosage for Biotin

The U.S. Food and Drug Administration (FDA) has not established a recommended dietary allowance (RDA) for biotin.

According to the Food and Nutrition Board of the Institute of Medicine, 30 mcg is the daily adequate intake for adults 19 years of age and older, which can usually be achieved through dietary consumption. 

Although there is no recommended dietary allowance for biotin, proponents of biotin often recommend taking 2-5 mg (2000-5000 mcg) of biotin in supplement form daily in order to strengthen hair shafts and achieve results.

Although biotin is a water-soluble vitamin (excess is excreted in urine and feces), there is no evidence to support this recommendation and the safety of regular use of this amount isn't known. Some side effects and signs of overdose may include skin rashes, digestive upset, and kidney problems. 

As with other supplements, biotin hasn't been tested for safety in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications. You can find out more about how to use supplements safely here.

Using Biotin for Hair Growth

Although biotin deficiency is uncommon, it may occur in people who drink alcohol excessively or consume a great deal of raw egg white (which contains avidin, a protein that blocks the absorption of biotin). Two or more uncooked egg whites daily for several months has been known to result in biotin deficiency. Genetic disorders of biotin deficiency, renal dialysis, and smoking may also increase your need for biotin. Certain drugs may reduce biotin levels, such as carbamazepine, phenobarbitol, primidone,  and other anticonvulsants.

If you notice any symptoms of biotin deficiency, consult your physician. Symptoms include thinning of the hair, a red scaly rash (especially around the eyes, nose, and mouth), depression, exhaustion, hallucinations, and tingling of the arms and legs.

Most people can meet their daily biotin needs by consuming biotin-rich foods like brewer's yeast, nutritional yeast, liver, cauliflower, salmon, bananas, carrots, egg yolks, sardines, legumes, and mushrooms. If you're considering the use of biotin for hair growth, talk to your doctor before starting your supplement regimen.


Camacho FM, García-Hernández MJ. "Zinc aspartate, biotin, and clobetasol propionate in the treatment of alopecia areata in childhood." Pediatr Dermatol. 1999 Jul-Aug;16(4):336-8.

Daniells S, Hardy G. "Hair loss in long-term or home parenteral nutrition: are micronutrient deficiencies to blame?" Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):690-7.

National Institutes of Health. "Biotin: MedlinePlus Supplements". April 2011.

Rajput RJ. "Controversy: is there a role for adjuvants in the management of male pattern hair loss?" J Cutan Aesthet Surg. 2010 May;3(2):82-6.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.

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