Biotin For Hair Growth: Does It Work? What The Research Says & Usage Tips*

If you're on a mission to grow healthy locks, you've likely heard of biotin.* The nutrient is a popular ingredient in not only hair and beauty supplements but multivitamins as well. But how does biotin work for hair growth, exactly? Read on to learn about the buzzy nutrient, plus what to look for in a supplement.   

Biotin, or B7, is a water-soluble vitamin. It's part of the B complex, which includes eight B vitamins that are essential for important cellular reactions in the body.* Case in point: Biotin plays a major role in energy production; specifically, it's a coenzyme for carboxylases1, or enzymes that help metabolize macronutrients (i.e., carbohydrates, fats, and proteins) into fuel for the body.* Carboxylases are also involved in biological processes like insulin release2, fatty acid production3, and gluconeogenesis4 or the synthesis of glucose. Moreover, biotin is a well-known beauty nutrient, as it can help support hair, skin, and nail health.*

Your body cannot make biotin5 on its own. And while the bacteria in your gut5 can produce it to a certain extent, they also need biotin to grow and survive6.* Thus, they might "compete" with the host (i.e., you), so you'll need to get biotin through the diet to meet your needs. Natural food sources include beef liver, salmon, animal meats, eggs, cheese, sunflower seeds, spirulina, and nutritional yeast. You can also find it in supplements, including B-complex vitamins that when complete, contain the other seven B vitamins (thiamin, riboflavin, niacin, pantothenic acid, folate, B6, and B12). Biotin is also a common ingredient in beauty supplements, particularly those with collagen, as both nutrients offer hair and skin benefits.*

Biotin is a well-known hair vitamin—and for good reason, too. Here's what the nutrient can do for your locks:*

Research shows that not getting enough biotin2 can lead to hair shedding, but taking a biotin supplement can provide support.* (We should note that lacking biotin is rare in the U.S. population, however.) The vitamin helps nourish hair follicles, says board-certified Debra Jaliman, M.D.* This is important because each hair follicle is in charge of securing or "anchoring" each hair to the skin. According to Jaliman, biotin also stimulates the growth of existing hair, as it's involved in the production of keratin, the main structural protein in hair.* One small study found that women who took supplemental biotin experienced notable hair regrowth than the placebo group.*

Healthy, strong hair is often naturally shiny and glossy. But of course, like glowing skin, achieving healthy hair isn't just about using the right products. It also relies on adequate levels of nutrients that support hair growth and strength—like biotin.* After all, not getting adequate amounts of biotin can lead to dull and lackluster hair, according to board-certified hair loss surgeon William Yates, M.D.* Thus, "if your hair is dry and brittle, you might want to consider a biotin supplement,"* says Jaliman.

Did you know that your scalp has its own community of bacteria? Yes, it's true. They're collectively known as the scalp microbiome, and they're involved in regulating hair health and scalp issues, including flakes and the like. According to research, biotin is essential for supporting this unique microbiome7 and its functions for scalp health.*

Over time, hair shedding can make your mane look limp and thin. But as biotin supports healthy hair growth, it can also contribute to more voluminous and fuller-looking locks.* Similarly, biotin's role in healthy hair follicles and the scalp microbiome can strengthen your hair, ultimately making it appear fuller.*

When shopping for a biotin supplement, here are a few things to keep in mind:

Your biotin needs might be higher if you have low levels, like between 5,000 to 10,000 micrograms (5 to 10 milligrams), according to Jaliman. Here are some other reasons you might need to pay special attention to biotin levels:

Also, keep an eye out for supplements with both biotin and collagen, which is the main structural protein in the skin.* Collagen contains amino acids that are necessary for keratin production and, therefore, hair growth.*

In general, biotin is considered to be a safe vitamin. It's also difficult to take too much of the nutrient due to its water-soluble nature. (In other words, excess amounts are simply excreted via the urine11.) But as with any supplement, it's important to check with your doctor before taking biotin. This will ensure the supplement won't interact with medications or other aspects of your health routine. Also, in some cases, high doses of biotin may affect hormone levels, including those related to healthy thyroid function15. Let your doctor know if you've been taking biotin, especially if you need routine hormone tests.

If you're experiencing hair struggles due to a lack of biotin, you should see results in "two to three months once you increase your dosage to the recommended amount,"* says Jaliman. However, this time frame will be influenced by many factors, including the degree of your needs, the original health of your hair, and your hair routine.

Biotin is a common ingredient in topical hair care products. In this form, it will strengthen the surface of your hair strands, according to Jaliman. However, biotin's hair benefits are less effective when applied topically, she adds. So, if you're looking to get the most hair benefits from biotin, supplements may be the way to go.* 

Biotin is a B vitamin that is often used in beauty and hair supplements as it can support healthy hair growth thanks to its role in keratin production and promoting scalp health.* If you're looking for a supplement to promote long, shiny locks—this may be the one for you.* For additional hair nutrient ideas, check out our full rundown of supplements for dry hair.*