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Ranking the best biotin supplements of 2021

Written by John Davis

Last updated: November 27, 2020

Biotin is a B vitamin that plays a critical role in a wide range of bodily functions. It’s sometimes also known as vitamin B7 or vitamin H, and it appears to impact your body’s ability to synthesize proteins for skin, hair, and metabolic functions involving fat or glucose.

The research on biotin is still in its early stages, but people are hopeful that it can be used to improve hair thickness, fight brittle nails, and even improve metabolic health and control blood sugar.

Our research team looked into the best biotin supplements out there; here’s what we came up with.


1. Biotin Pure + by Nuzena

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Nuzena is a new, premium supplement line famous for its potent concentrations.

Biotin Pure + by Nuzena is a beast of a biotin supplement. Nuzena offers a maximum strength biotin supplement packing in 10,000mcg of Biotin per capsule. 

(+ 179 mg of calcium)

Where Nuzena really shines through is in the quality of their supplements. Their Biotin Pure + supplement is gluten-free, Non-GMO, sugar-free, sustainably sourced, and even vegan friendly.

There’s also plenty of good customer feedback on this product too — all with purchase verifications too, which is a great trust indicator.

All things considered, we give Biotin Pure + the well deserved #1 spot for the best biotin supplement.

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2. Natrol Biotin Maximum Potency 

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Natrol makes a high-dosage biotin supplement with a little bit of calcium added (66 mg to be exact). It comes in a vegetable cellulose capsule and is free from most common allergens like dairy, soy, and nuts.

Its dosage is on the high end, at 10,000 micrograms. Natrol also makes lower dosage biotin supplements, but these aren’t as popular.

3. Sports Research High Potency Biotin

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Sports Research is known for high-quality supplements, and their biotin offering fits the bill.

With 10,000 micrograms of biotin and the United States Pharmacopeia mark guaranteeing extremely high purity and dosage accuracy, it is a very solid go-to biotin supplement. The compound is dissolved in coconut oil and beeswax, and comes in a vegan-friendly softgel.

4. Solgar Super High Potency Biotin

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Solgar makes a simple, straightforward, no-BS biotin supplement. It delivers 10,000 micrograms and nothing else, save for a vegetarian-friendly cellulose capsule and a few binders to hold the capsule together, making it an excellent pick.

Given Solgar’s good reputation for purity and supplement quality, it’s a good buy for anyone who wants a minimalist high-dose biotin supplement.

5. Zhou Hairfluence

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Zhou Hairfluence is more of a total solution to hair thickness and fullness—yes, it’s got biotin, but it’s also got about a dozen other ingredients, including other B vitamins, pantothenic acid, MSM, collagen hydrolysate, and even pure keratin (the protein hair is made out of).

The theory here is to load up your body with all the ingredients it needs to pump out hair as fast and as thick as possible. As a biotin supplement, it functions pretty well, delivering 5,000 micrograms per dose (however, do note that a dose is two capsules, not one).

Zhou Hairfluence is well-reviewed, so if you want a multi-ingredient hair supplement, this is the one to go with. If all you want is biotin, there are better options.

6. NOW Biotin

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NOW Biotin is a safe bet for a simple biotin supplement. NOW is a large and fairly well-regarded vitamin and supplement company, and their 10,000 microgram biotin supplement is pretty solid: no red-flag ingredients and no common allergens.

NOW also makes a 1,000 and 5,000 dose version of their biotin supplement, too, if you’d like a lower dosage biotin supplement with the same quality.

7. Webber Naturals Biotin

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Webber Naturals biotin provides a 5000 microgram biotin supplement.

This non-GMO, vegan, dairy and sugar free product gives you the biotin you need while maintaining a clean product.

8. VitaFusion Extra Strength Biotin

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VitaFusion’s biotin is the only gummy-based supplement on the market, so it’s one of your only options if you don’t want or don’t’ like pill based supplements.

You do have to be okay with the fact that these gummies are gelatin-based and include some artificial flavoring and coloring, though. At 5,000 micrograms per dose, they are middle of the road when it comes to dosage.

9. Nature’s Bounty Biotin

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Nature’s Bounty offers a few different dosages of biotin, but the 10,000 microgram version is the most popular. While it’s pretty simple to make a biotin supplement, Nature’s Bounty seems to have cut a few corners here.

The biotin is dissolved in soybean oil, which won’t sit well with the anti-soy crowd, and the capsules are colored with titanium dioxide (for aesthetic purposes).

10. SBR Nutrition Biotin

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SBR Nutrition’s biotin supplement is unique in its form of delivery. It comes in a dropper bottle, which allows you to measure out arbitrary dosages of biotin.

It is flavored with natural vanilla and stevia to make the taste palatable, but unless you really dislike pills or have a good reason for wanting a liquid source of biotin, you should probably just opt for a capsule-based supplement.

Category winners

Best biotin overall: Biotin Pure + by Nuzena

Nuzena is well-regarded for their extremely high quality supplements, and Biotin Pure + is an excellent example. With a high dosage and nothing in the way of extraneous ingredients, Biotin Pure + is the perfect all-around pick. 

Best biotin for hair: Zhou Hairfluence

Zhou Hairfluence provides a strong dose of biotin alongside other hair-strengthening compounds like B vitamins, collagen, and keratin. This multi-ingredient blend is the best way to give your body the building blocks it needs for stronger and thicker hair. 

Best biotin for nails: Natrol Biotin Maximum Potency

Natrol’s biotin supplement is high in dosage and low in extra additives. Since nails grow so slowly, you’ll want to deliver a high and consistent dose over the long term to strengthen your nails, and that’s exactly what Natrol Biotin is best-suited for. 

Best biotin for skin: Biotin Pure + by Nuzena

Keeping skin strong with biotin is similar to keeping nails and hair strong: you want a strong, consistent dosage. Nuzena goes the extra mile by providing this in ultra-pure high dose capsules, plus a little calcium for collagen integrity. 

Best biotin for men: Solgar Super High Potency Biotin

Men looking to use biotin for thicker and stronger hair can take advantage of the high dosage available in Solgar Super High Potency Biotin—since men’s focus is primarily on hair thickness and strength, and less so on shine and texture, they benefit more from a pure biotin supplement versus a general-purpose hair supplement with multiple active ingredients. 

Best biotin for metabolic health: Sports Research High Potency Biotin

If you are looking to use biotin to improve your metabolic health and better-control your blood sugar, Sports Research High Potency Biotin is a great choice, especially in combination with a chromium supplement. Sports Research delivers their biotin in coconut oil, and does so at a dose that’s well-situated to help control blood sugar. 

Who should buy biotin?

Biotin is a specialized supplement that can help improve the thickness and quality of your nails and hair. If you have brittle nails or dry, thin, and brittle hair, biotin might be able to assist.

As a naturally-occuring B-vitamin, it plays an important role in the synthesis of the proteins that make up both hair and nails (believe it or not, they are nearly identical in their makeup).

Beyond the hair and nail uses of biotin, there’s also some preliminary evidence that biotin, alongside chromium, may be able to improve your control over your blood sugar.

How we ranked

To make our rankings, we first took stock of the wide range of biotin-containing supplements on the market. Some of these were dedicated biotin supplements, while others used biotin alongside other supplemental ingredients.

First, we excluded anything that wasn’t either a biotin-only formulation or a blend that specifically focused on hair and nail health. While biotin plays a role in many other biological functions, if you are taking a biotin supplement, you are probably looking to leverage its nail and hair health benefits.

Next up, we took a look at the dosage. We made there was more than the recommended daily intake of biotin, but also ensured that the supplement dosage did not exceed 10 mg (or 10,000 micrograms), as the safety of biotin has not been studied at dosages beyond this level.

We also closely examined the other ingredients in the supplement, and had strong preferences towards clean supplement design: no unnecessary fillers, binders, or coloring agents. With very few exceptions, liquid-based biotin supplements did not make it past the cut.

They typically did not have the right dosage level, and had too many solvents or flavoring agents to make it worth taking. Liquid supplements also pose a dosage problem, where it is hard to get an accurate amount of liquid from just an eyedropper bottle. Capsule-based supplements have more precisely measured dosages, so it’s easier to know how much biotin you are getting.

Finally, we took stock of any other active ingredients which could exert a synergistic or beneficial effect. Zhou’s Hairfluence moved up in the standings at this point, thanks to its inclusion of MSM, folate, and other beneficial nutrients, as did Natrol Biotin, our top-ranked supplement, thanks to its extra calcium. The final ten biotin supplements all deliver pure and effective dosages to strengthen hair, fight brittle nails, and improve blood sugar control.


Biotin is a less well-known 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.

Biotin could help you with 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.

Biotin might help with skin health too. Other work, such as a review by D.M. Mock, 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.

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).

The study evaluated the patients and prescribed them a biotin supplement to take for a period of several weeks.

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.

If fully two-thirds of people with brittle nails respond to a biotin supplement, this suggests that biotin deficiency is more widespread than previously thought, at least among people with brittle, thin nails.

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.  

This might not seem particularly relevant for hair thickness, but consider this: despite their vastly different appearance, fingernails and hair (as well as cattle hooves and horse hooves) are actually made of the same thing.

The protein keratin is the primary thing that makes up both your nails and your hair, and that’s exactly the protein whose synthesis appears to be increased by biotin in the people who took the biotin supplement for brittle nails.

So, from this, it follows that people with thin or brittle hair might respond in the same way to a biotin supplement.

Biotin may be able to help increase hair thickness by up to 25%. If the response rate was similar, 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.

Don’t make the common mistake of thinking that biotin is for preventing 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.

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).

In a placebo-controlled trial, the supplement 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.

The role that biotin plays in your body is not limited to hair, skin, and nails, as this study shows. Biotin plays a key role in a wide range of cellular interactions inside your body, so the full extent of its health benefits have likely not been fully researched.

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).

Pregnancy increases your body’s requirement for several of the other B vitamins, so nutrition researchers have wondered whether a similar effect might be seen with biotin. Several pieces of evidence indicate that this might be the case. First, biotin deficiency is associated with birth defects in many other mammals.

Second, in women who are pregnant, there are increased levels of a specific biomarker for biotin, which could indicate that biotin levels are lower among women who are pregnant because biotin is being depleted faster than it is being replaced.

A study published in the American Journal of Clinical Nutrition attempted to answer the question of whether pregnancy might induce biotin deficiency (5). The study took 26 women who were pregnant and randomly supplemented them with either a placebo or a biotin supplement.

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.

Side 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. 

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 (5).

Recommended dosage

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 (6).

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.

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.

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.


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 B-vitamin is biotin?

A: Biotin is designated as vitamin B7. It belongs to the category of B vitamins because it is a cofactor in cellular reactions that regulate the basic energetic functions of the cells in your body.

As with the other B vitamins, such as folate, niacin, cobalamin, and many others, biotin is water-soluble and, though only necessary in trace amounts, plays a key role in keeping your body’s internal mechanics functioning.

Q: What is biotin made of?

A: Unlike many supplements, biotin is not something only found in certain plants and herbs. It’s a critical micronutrient with a fairly simple chemical structure, and can be found in nuts, seeds, fish, dairy, and avocados, to name just a few foods.

Some strains of probiotic bacteria also produce biotin on their own, so you get some of it as a part of having a normal and healthy gut bacteria.

So, biotin is not really “made of” anything other than the individual atoms that make up the biotin molecule. In this manner, it’s similar to many of the other alphabet vitamins in that it is an individual, distinct molecule with a specific biological purpose (or several purposes, as is the case with biotin and many other B vitamins).

Q: What are the uses of biotin?

A: As a supplement, the primary uses of biotin are strengthening your hair and your nails. Some of the hallmark symptoms of biotin deficiency are brittle nails and thinning and fragile hair, which is caused by dysfunction in the biological reactions that synthesize both hair and nail cells (which happen to be made out of the same protein).

The thought, which is supported by some clinical evidence from scientific research, is that supplying additional biotin can help your body ensure that your hair and nails are as healthy as possible.

Some emerging scientific research also suggests that biotin, alongside chromium, may help improve blood sugar control in people who have metabolic syndrome or are prediabetic, though there’s more research that needs to be done to establish whether or not biotin could be a useful regulator of blood sugar.

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: Does biotin help with weight loss?

A: So far, no solid scientific research has indicated that biotin would be a useful weight loss supplement. People on very restrictive diets, or who have had gastric bypass surgery as an obesity treatment, may be at risk for developing a biotin deficiency, though.

One case study describes a patient who had a gastric bypass surgery who subsequently developed a complete loss of taste. Doctors were able to restore it with high-dose biotin supplementation (6). This report does suggest that biotin deficiency might be a side effect of aggressive weight loss or very restrictive diets, but more research is needed to confirm these results.

Q: Is 10,000 mcg the best dose of biotin?

A: 10,000 mcg is the highest dosage that’s been determined to be safe in nutritional studies. A few medical studies have reported using 40,000 mcg to treat deficiencies and have not had any adverse effects, but in terms of nutrition studies, 10,000 mcg (which is the same as 10 mg) is the upper limit.

This dosage is far above the recommended daily intake of 30 mcg, but this threshold was developed purely from population surveys of biotin intake—the theory being that the average biotin intake of a healthy person would have to be a sufficient amount. Technically, the actual biological need for biotin in your body has not been definitively determined.

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.

Today, infants are routinely screened for deficiencies in the enzymes that process biotin in your body; a genetic predisposition for biotin deficiency would be picked up soon after birth.

However, this screening process only became routine late in the 1980s, so if you were born before then, you would not have been screened for biotin deficiency.

The other common cause of biotin deficiency is an excessive consumption of uncooked egg whites. This is a seemingly perplexing cause of biotin deficiency; eggs, after all, are rich in biotin. However, it turns out that 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. It’s one of the core ingredients in vitamins for hair growth, and some scientific evidence suggests that a biotin supplement could help repair damaged hair and nails if this damage is associated with an insufficient amount of biotin in your body.

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.

Q: How much is too much biotin?

A: Right now, the nutritional recommendations are that you not exceed 10,000 mcg (or 10 mg) of supplemental biotin per day. It’s not that doses beyond this have been proven harmful; rather, doses beyond this range have not been studied in detail, so their safety can’t be guaranteed.

A few case reports in the medical literature have used doses of up to 40 mg for a short period to treat severe biotin deficiencies, and did not have any negative side effects, though these were not systematic studies.

Since most people seem to only need around 30 mcg of biotin to stay healthy, super-high doses of biotin probably aren’t necessary, even if you think you have a deficiency.

Related articles


Biotin is a very safe B vitamin supplement that might help you grow thicker hair, repair brittle and thin nails, and even control your blood sugar.

It’s safe in doses at least up to 10 mg per day, and though the research on its uses is in its early stages, there are promising signs that it could be effective at improving the health of your skin, nails, hair, and blood sugar control.  

For BodyNutrition‘s #1 biotin recommendation, click here.


John Davis

John Davis is a Minneapolis-based health and fitness writer with over 7 years of experience researching the science of high performance athletics, long-term health, nutrition, and wellness. As a trained scientist, he digs deep into the medical, nutritional, and epidemiological literature to uncover the keys to healthy living through better nutrition.