There aren’t a lot of supplements that can help with skin and hair health, but biotin is one of them. It’s a B-vitamin that your body uses to synthesize the proteins that make up skin, hair, and nails.
Biotin finds wide usage among people looking for stronger, thicker hair, less brittle nails, and better-moisturized and more elastic skin.
Here’s why there’s a strong case for taking biotin for nail, hair, and skin health.
1. Biotin is a member of the B vitamin family
The B vitamins are a versatile and critically important group of nutrients, and biotin is no exception. Vitamin B7, as it’s sometimes known, helps grow your hair, strengthen your nails, and process fats and sugar in your diet.
Despite this, it’s still a fairly new nutrient in the world of nutrition, so the full breadth of its utility isn’t yet known. Many people swear by biotin’s ability to help you grow thicker hair, stronger nails, and even control your weight and blood sugar.
2. Biotin could improve hair and nail health
Biotin initially arose interest from the supplementation when people started taking note of the effects of biotin deficiency. A small percentage of people are born with a genetic defect that prevents their body from effectively metabolizing biotin.
A case study published in The Lancet in 1979 describes how biotin deficiency can cause marked hair thinning and a biological imbalance of enzymes in the blood (1). Upon administration of a biotin supplement, all of these symptoms reversed rapidly.
3. Biotin might help with skin health too
Other research has found that a lack of biotin can cause dry, scaling skin, as well as the proliferation of yeast infections in the skin and an impairment of immune system function (2).
All this raises an obvious question: can supplemental biotin cause the inverse of these effect? In at least some cases, the answer appears to be yes.
4. Biotin can help repair brittle nails
A scientific study published in 1993 in a journal on skin and nail conditions looked at patients who reported to a dermatology clinic with brittle nails (3).
Of the patients who took the biotin supplement, 63 percent showed a substantial improvement in their nail condition. Though the other 37 percent saw no improvement, we need to keep in mind that many conditions can cause nail brittleness.
The primary effect of the biotin supplementation in these patients who responded to the therapy was an increase in nail thickness. Other research found similar results, and biotin has even been used in cattle and cows to increase the thickness of their hooves.
So, from this, it follows that people with thin or brittle hair might respond in the same way to a biotin supplement.
5. Biotin may be able to help increase hair thickness
If the response rate for hair was similar as for nails, a large proportion of people could see substantial changes in their hair thickness–up to 25%, if the gains in nail plate thickness from biotin supplementation mirror those of hair follicle thickness.
Experiments testing this hypothesis directly are lacking, but that hasn’t stopped people from exploring its use as a method to increase hair thickness and strength.
Reviews are mixed, but some people do find that biotin supplements help them achieve stronger and fuller hair.
6. Don’t make the mistake of thinking that biotin is for hair loss
Unlike other supplements that are supposed to prevent hairs from falling out, there is no evidence yet that biotin does that.
What it might be able to do is make the shafts of hair you do have grow thicker and stronger–again, this is based off research on nail plate growth, extrapolating from the fact that hair and nails are made from the exact same protein.
7. Biotin also seems to help control blood sugar
Research published in 2008 in the scientific journal Diabetes Metabolism Research and Reviews tested the effects of a biotin and chromium picolinate supplement on blood sugar levels in overweight and obese people who had type 2 diabetes (4).
Biotin was able to lower their blood sugar levels substantially, leading the researchers to recommend it as a secondary treatment for type two diabetes.
Obviously, you’d want to talk to your doctor about this if this is relevant to you, but it’s an interesting direction for future research.
8. Biotin deficiency could occur during pregnancy
Many of the B vitamins are important during pregnancy to prevent birth defects (such as folate, which is an important ingredient in many prenatal vitamins).
A study published in the American Journal of Clinical Nutrition attempted to answer the question of whether pregnancy might induce biotin deficiency (5).
The researchers were able to show that the biotin supplement significantly increased biotin levels, and that the urinary excretion of the biotin biomarker seen in other research studies was indeed indicative of a mild or moderate deficiency of biotin in pregnant women.
Thanks to the result of this study, you’ll often find biotin included in prenatal vitamins, alongside the other more famous B-complex vitamins that are necessary during pregnancy.
Biotin side effects
Biotin does not seem to cause any adverse effects. As a B vitamin that occurs in a host of food products, it’s hard to get too much biotin. There is no well-characterized side effect profile.
Biotin has only been studied at doses up to 10 mg per day (10,000 micrograms). According to the Mayo Clinic, there are no known side effects of biotin supplementation, even up to 10 mg per day–this is on the high end of what’s available as an over-the-counter supplement (6).
Most supplements provide a lot more than the recommended daily intake of biotin. The recommended daily intake for biotin is pretty small compared to what’s available in a supplement.
Data published by the National Institutes of Health’s Office of Dietary Supplements outlines a minimum intake of 30 micrograms of biotin per day for healthy adults (7).
However, this dosage is just to maintain normal, healthy levels of the vitamin. As for strengthening nails or increasing hair volume and thickness, doses may need to be higher, though how much higher is not clear.
Biotin is safe at high doses, but the optimal dose for hair health is unknown. Because biotin has an excellent safety profile, the good news is that you can experiment with a wide range of doses to see if biotin is effective for you.
Try a few different dosage levels to see what works for you; there isn’t enough research yet to properly characterize how much biotin you need to get the benefits.
Keep the max dosage below 10 mg per day. It’s probably best not to stray beyond 10 mg per day (equivalent to 10,000 micrograms) per day, since the safety of biotin hasn’t been evaluated beyond this level.
That is already a couple hundred times your normally-required daily intake, so if there was an effect of biotin, you’d expect to see it by that point.
Biotin benefits FAQ
Q: What is biotin?
A: Biotin is a B-vitamin that is incorporated into a multitude of enzymes in your body. These enzymes help build cells, metabolize the food you eat, and regulate how your body distributes fat and carbohydrates within cells.
Biotin’s role in these reactions is to assist the enzymes that make these chemical reactions happen. It’s not an herbal extract or a plant-derived compound; it’s a micronutrient much like vitamin C or vitamin E.
Q: What foods are high in biotin?
A: You can find substantial amounts of biotin in liver, egg, salmon and tuna, beef, almonds, and sweet potatoes, to name a few of the best sources.
Both omnivores and vegetarians or vegans can find great sources of biotin, though if you are looking for a serious dose of biotin, you’ll need to opt for a lot of liver or eggs (which have 10 and 5 mcg per serving, respectively), or take a supplement to get more.
If you are relying on eggs to get your biotin, make sure they are fully cooked: undercooked egg white actually impedes biotin absorption to a significant extent. Most of the biotin in eggs actually resides in the yolk.
Q: What causes biotin deficiency?
A: Biotin deficiency is rare, but does occur. Typically, biotin deficiency is associated with brittle nails, fragile, dry, and thin hair, and rashes on your skin. Biotin deficiency is usually caused by one of two things: either a genetic mutation or an excess of raw egg white in your diet.
The biotin in eggs is contained mostly in the yolk, while egg whites contain a compound that significantly inhibits biotin absorption.
This compound is deactivated by cooking, though, so fully cooked eggs pose no threat of causing biotin deficiency.
Q: What is biotin good for?
A: Biotin plays a huge number of roles in your body, but when taken in supplemental form, is most commonly used to improve the quality of your nails and your hair.
While biotin is involved in many cellular reactions, one of the first manifestations of a biotin deficiency is a decrease in the integrity and health of your nails and hair.
These symptoms are linked because of the protein keratin, which makes up both hair and nails.
Related: Our best biotin picks
Biotin helps your body form the essential building blocks for stronger, healthier hair, skin, and nails.
Biotin has been shown to improve hair thickness, nail strength, and skin quality, making it a great supplement to take as a part of your skincare, nailcare, and haircare routine.