Biotin is a vitamin often recommended for healthy hair. 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 growth. However, there is very little evidence to support the claim that biotin can enhance hair health. Biotin is also used to promote healthy nail growth.
Thinning Hair or Hair Loss
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.
Recommended Dosage for Biotin
Although there is no recommended dietary allowance for biotin, proponents of biotin often recommend taking 5000 mcg of biotin in supplement form daily in order to strengthen hair shafts. There is no evidence to support this recommendation.
Should You Take 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 a protein that blocks the absorption of biotin). Genetic disorder of biotin deficiency, infant seborrheic dermatitis, and surgical removal of the stomach may also increase your need for biotin.
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.