Biotin: Side Effects and Benefits You Should Know About

Often touted as a solution for weak nails and hair growth, biotin is a common supplement. But do these claims stack up when it comes to the actual scientific evidence? Join us as we explore the research behind it.

What is biotin?

Biotin, also called vitamin B7 or vitamin H, is important for many body functions. It helps with metabolism, pregnancy, and breastfeeding. It also supports the nervous system, regulates blood sugar, and promotes healthy hair, skin, and nails. 

Biotin is a water-soluble vitamin that plays a crucial role in converting food into energy. It helps the body break down carbohydrates, fats, and proteins, making it essential for overall health. 

It is a key player in the metabolic breakdown of carbohydrates, fats, and proteins. As a coenzyme, it participates in many metabolic reactions, leading to the generation of glucose and fatty acids [1].

Biotin becomes particularly crucial during pregnancy and breastfeeding. It’s been found that these life stages can result in a deficiency, possibly due to increased demand [2].

It contributes to the nervous system’s functioning, affecting neurotransmitter activity and aiding nerve signal conduction [3]. Additionally, it supports skin health, which is essential for sensory information processing [4].

Early studies suggest that biotin, usually paired with chromium, might help manage blood sugar levels [5-6]. This is particularly relevant for people with type 2 diabetes. If this turns out to be the case in further studies, it may be useful for reducing the impact of aging.

Foods rich in biotin

Biotin is naturally found in a variety of foods, some of which are shown below [7]. 

• Legumes 
• Bananas
• Egg yolks
• Salmon
• Cheese
• Sardines
• Pork
• Chicken
• Turkey
• Spinach
• Almonds
• Walnuts
• Peanuts
• Raspberries
• Sunflower seeds
• Mushrooms
• Avocados
• Sweet potatoes
• Yeast
• Yogurt

It’s important to note that raw egg whites have a protein called avidin. This protein can block biotin absorption if regularly consumed [7]. So if increasing the intake of biotin is the goal, you may want to avoid the whites. 

Most people get enough biotin from their diet, and deficiencies are rare. While supplements are certainly available, if you are eating a healthy balanced diet, there should be no need to take them.

People with keratin-related issues should consult a medical professional. They can help to determine the root causes and judge whether or not supplements are necessary.

Does biotin promote hair growth?

Some studies suggest that biotin supplements may help fortify brittle nails and possibly hair [8]. And while it is often marketed for hair growth, scientific evidence supporting this claim is quite limited.

Biotin is indeed a crucial part of the natural process of hair production. It’s essential for creating keratin, the protein that constitutes hair, skin, and nails. However, this doesn’t necessarily mean it promotes hair growth in people with normal levels [9]. Numerous factors, including genetics, diet, stress, and overall health, influence hair health and growth.

The hair growth benefits are mostly seen in people with biotin deficiencies. These deficiencies are rare but can cause hair thinning and skin rashes. In these cases, supplementation may help restore hair health [10].

It is still unclear if extra biotin can really help hair health or growth in people who already have adequate levels. A review from 2017 highlighted the lack of rigorous clinical trials on its effect on hair growth in healthy people [11].

While it is an interesting vitamin, a lot more research needs to happen to draw firm conclusions. Meanwhile be wary of marketing that suggests otherwise until more studies are conducted.

Biotin side effects

It is a vitamin that is usually safe and well-tolerated, even at high levels of intake. The United States Food and Drug Administration hasn’t established a recommended dietary allowance for biotin [12]. But it typically doesn’t cause side effects when used as recommended.

However, high levels can potentially distort the results of certain lab tests. For example, thyroid and other hormone tests, leading to incorrect results. This might result in misdiagnosis or improper treatment [13].

There are also other potential side effects and considerations, namely the possibility of skin reactions. Biotin supplements, although rare, can cause skin rashes, typically due to allergic reactions [14].

Lastly, there are anecdotal reports from some people supplementing with it that it can lead to insomnia. Given that it is used by the body to turn fats and carbohydrates into energy, a high intake could lead to an energy boost. This could potentially make sleeping more difficult or even contribute to insomnia. To avoid any potential of this happening, it might be best to take it after getting up in the morning.

Disclaimer

This article is only a brief summary and is based on the interpretation of research data. This article is not a substitute for consulting your physician about which supplements may or may not be right for you. We do not endorse supplement use or any product or supplement vendor.

Literature

[1] Zempleni, J.; Wijeratne, S.S.K.; Hassan, Y.I. Biotin. Biofactors 2009, 35, 36–46

[2] Furukawa, Y. [Enhancement of Glucose-Induced Insulin Secretion and Modification of Glucose Metabolism by Biotin]. Nihon Rinsho 1999, 57, 2261–2269.

[3] Vitamins and Minerals: Their Role in Nail Health and Disease

[4] Zempleni, J.; Mock, D.M. Marginal Biotin Deficiency Is Teratogenic. Proceedings of the Society for Experimental Biology and Medicine 2000, 223, 14–21

[5] McKay, B.E.; Molineux, M.L.; Turner, R.W. Biotin Is Endogenously Expressed in Select Regions of the Rat Central Nervous System. Journal of Comparative Neurology 2004, 473, 86–96

[6] Lipner, S.R. Rethinking Biotin Therapy for Hair, Nail, and Skin Disorders. J Am Acad Dermatol 2018, 78, 1236–1238

[7] Zempleni, J.; Kuroishi, T. Biotin. Advances in Nutrition 2012, 3, 213–214

[8] Romero-Navarro, G.; Cabrera-Valladares, G.; German, M.S.; Matschinsky, F.M.; Velazquez, A.; Wang, J.; Fernandez-Mejia, C. Biotin Regulation of Pancreatic Glucokinase and Insulin in Primary Cultured Rat Islets and in Biotin-Deficient Rats. Endocrinology 1999, 140, 4595–4600

[9] Patel, D.P.; Swink, S.M.; Castelo-Soccio, L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord 2017, 3, 166–169

[10] Trüeb, R.M. Serum Biotin Levels in Women Complaining of Hair Loss. Int J Trichology 2016, 8, 73–77

[11] Lipner, S.R.; Scher, R.K. Biotin for the Treatment of Nail Disease: What Is the Evidence? J Dermatolog Treat 2018, 29, 411–414

[12] Biotin – Health Professional Fact Sheet

[13] Li, D.; Radulescu, A.; Shrestha, R.T.; Root, M.; Karger, A.B.; Killeen, A.A.; Hodges, J.S.; Fan, S.L.; Ferguson, A.; Garg, U.; et al. Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults. JAMA 2017, 318, 1150–1160

[14] Keller, E.B. Biotin and Skin Sensitivity. J Allergy (Cairo) 1942, 14, 87–8