Is Biotin Actually Good for Skin, Hair, and Nails?

Some say the vitamin is the secret to longer hair, stronger nails, and better skin, but is that actually the case? Here, experts discuss.

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Photo: Getty Images/kokouu

If you've ever wanted longer hair or stronger nails, you've probably heard of — or even taken — biotin. The vitamin is the star of the show in a wide array of beauty and hair supplements, but is there any validity to all of the biotin buzz?

What is biotin?

Biotin, also known as vitamin B7 and vitamin H, is one of many B-complex vitamins, says Gretchen Frieling, M.D., a triple board-certified dermatopathologist in Boston. "It's a water-soluble vitamin, meaning it's not stored in the body and any excess is eliminated through urine," she explains.

There are plenty of biotin-rich foods, including ones most people eat daily, such as almonds, sunflower seeds, egg yolks, dairy, avocados, sweet potatoes, and spinach. Most people get plenty of biotin via their diet, says dermatologist Keira Barr, M.D. Plus, it's also produced by the bacteria in your gut, she adds.

The vitamin is essential for overall health, not just healthy skin and nails. "It's useful in metabolizing carbohydrates, fats, and proteins into energy, meaning it's important for metabolic health, as well as for maintaining nervous system functions," notes Dr. Frieling. Plus, it's also essential for embryonic growth during pregnancy, and some studies have shown it can also reduce bad cholesterol (LDL) levels, she adds.

So, is biotin good for skin, hair, and nails?

The big takeaway here: Biotin is, in fact, an essential nutrient for healthy skin, hair, and nails, says Dr. Frieling.

And there have been studies to back this up. For example, clinical studies show that biotin supplements can improve hair growth, says Howard Sobel, M.D., a board-certified dermatologic cosmetic surgeon based in New York and director of Sobel Skin. A daily 2.5 microgram biotin supplement improved nail thickness and reduced flaking after several months, according to a small Journal of Dermatological Treatment study.

Credit the vitamin's effect on keratin. Biotin has been found to strengthen the infrastructure of keratin, a key protein found in both hair and nails. There's also been some indication that biotin supplementation can help alleviate dry, itchy rashes, which is likely linked to its ability to produce skin-nourishing fatty acids.

The caveat? All of these studies and reported benefits occur in people who are biotin deficient to begin with, and very few people actually have a true biotin deficiency since it's found in so many of the foods you eat.

Case in point: While there's no recommended dietary allowance for biotin, according to the Mayo Clinic, the recommended daily intake for teens and adults is 30–100 micrograms. And, per the National Institutes of Health, the average intake in Western populations is 35–70 micrograms. In other words, most people are getting enough of the vitamin without needing to take supplements.

Basically, if you're not biotin deficient, popping that supplement may not have much of an effect on your hair, skin, or nails — but it most likely won't hurt, either. "There hasn't been a large-scale study of biotin effects on normal hair, but it doesn't mean that biotin doesn't help normal hair grow healthier and faster," says Dr. Sobel.

Biotin is generally safe to take even if you're not deficient, adds Dr. Frieling. Plus, many of the more beauty-focused supplements blend it with a host of other nutrients and vitamins too. (Fun stat alert: In a survey of 300 dermatologists, 66 percent said they recommend dietary supplements to their patients, and 81 percent of those were for reasons related to hair, skin, and nails.)

Does biotin have any side effects?

If you want to give it a try, go for it (just keep your expectations realistic), but it's important to talk to your doctor before you start popping biotin on the reg for a few reasons.

One, if you're trying to address an issue such as hair loss, brittle nails, or dry scaly rashes (all symptoms of a biotin deficiency, FYI) you want to make sure that there's not something else causing those problems.

Two, biotin supplementation can make some funky stuff show up on blood work: "The FDA issued a recent warning that biotin consumption might significantly interfere with laboratory testing," warns Dr. Barr. "It can affect various blood tests, leading to false negatives or false positives," adds Dr. Sobel.

It's also worth being cautious if you struggle with acne. "We're seeing a link between biotin intake and increased acne, because excess biotin actually decreases the amount of vitamin B5 that's absorbed, a vitamin thought to help protect the skin's protective barrier and to help reduce acne," explains Dr. Sobel.

Are oral supplements the only option?

No, but you'll probably have better results with an ingestible supplement. "Given that our microbiome and gut bacteria play a role in synthesizing biotin, the bioavailability of the vitamin would be most readily available from an ingestible," says Dr. Barr.

Still, even though all of the current studies have been done with ingested biotin supplements versus topical applications, it doesn't hurt to use hair products or nail solutions with biotin in them, adds Dr. Sobel.

And, similar to ingestible biotin supplements, many topicals contain other ingredients that can be beneficial. For example, the Foligain Triple Action Complete Formula (Buy It, $24, contains both copper peptides and biotin, while the OGX Thick & Full Biotin & Collagen Shampoo (Buy It, $9, also has wheat protein and collagen to plump up strands. And for weak nails, swipe on the Butter London Horse Power Nail Rescue Basecoat (Buy It, $18, which contains both strengthening biotin and horesetail extract.

To be sure you're getting the most from your biotin supplements, consider one of these oral ingestibles:

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