Are Biotin Supplements the Miracle Beauty Fix Everyone Says They Are?

Some say the vitamin is the secret to longer hair, stronger nails, and better skin....but is it?

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? We asked top dermatologists to weigh in.

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 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 of us eat daily, like almonds, sunflower seeds, egg yolks, dairy, avocados, sweet potatoes, and spinach. Most people get plenty of biotin via their diet (clipboard that thought; we'll get back to it in a minute), says dermatologist Keira Barr, M.D., who adds that it's also produced by the bacteria in your gut.

What does biotin do?

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," says Dr. Frieling, who adds that it's also essential for embryonic growth during pregnancy and that some studies have shown it can also reduce bad cholesterol (LDL) levels.

What are the beauty benefits of biotin?

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 cosmetic dermatologic surgeon based in New York, and director of Sobel Skin. A daily 2.5 mcg 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 our 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 all occur in people who are biotin deficient to begin with. And, per our earlier point, very few people actually have a true biotin deficiency since it's found in so many of the foods we 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 mcg to 100 mcg. Per the National Institutes of Health in Western populations, average intake is 35-70 mcg. In other words, most people are getting enough of the vitamin without needing to take supplements. So, 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.

Dr. Frieling adds that biotin is generally safe to take even if you're not deficient. 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.)

A few to try:

  1. Hair La Vie Clinical Formula Hair Vitamins has 5000 mcg of biotin, plus 20 different natural ingredients such as flaxseed and bamboo stem. (Buy It, $60,
  2. Better Not Younger Significant Other Hair Fortifying Vitamins also have vitamins A, C, D3, and zinc. (Buy It, $25,
  3. myKind Organics Hair, Skin & Nail contains 2500 mcg of biotin and other good-for-your looks antioxidants, all derived from fruits, veggies, and herbs. (Buy It, $20,
  4. Nutrafol Core for Women uses biotin and a laundry list of studied plant extracts and antioxidants. (Buy It, $88,

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 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.

Do you need to take it as a pill?

No, but you'll probably have better results. "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 solution with biotin in it, adds Dr. Sobel.

And per our same point as with the supplements, many contain other ingredients that can be beneficial. The Foligain Triple Action Targeted Formula for Thinning Hair for Women (Buy It, $30, contains both copper peptides and biotin, while the OGX Thick & Full Biotin & Collagen Shampoo ($8; 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.

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