Is Taking Biotin for Hair Growth Actually Effective?

Hair Health Hotline is your direct access to dermatologists, trichologists, hairstylists, and other beauty pros. Each story in this series tackles a common hair or scalp concern and offers science-backed solutions to care for your strands.

In the search for hair loss solutions, biotin is pretty inescapable. Whether you start scrolling through TikTok, studying Amazon reviews, or surveying friends, you're bound to hear mention of the vitamin before long.

Thing is, you're likely to run into both glowing reviews and claims that the recommendation to take biotin for hair growth is off-base. To give you the full story on whether the supplements live up to their reputation, Michelle Henry, M.D., F.A.A.D., a dermatologist at Skin and Aesthetic Surgery of Manhattan, is sharing the details on biotin and hair growth below.

Q: "I know that a lot of people take biotin for hair growth, and I've been dealing with hair loss. Does it actually work?"

A: Taking biotin pills for hair growth may be effective, but at this point, research backing this up is limited, according to Dr. Henry.

But before getting into the studies, a word on what biotin is and the role it plays in your body. "Biotin, also known as Vitamin B7, is a water-soluble vitamin that can be found in various food sources, such as dairy products and fruits," says Dr. Henry. "Biotin is a natural cofactor necessary for normal gene regulation, cell signaling, and the metabolism of carbohydrates, proteins, and fats." In other words, biotin allows enzymes in your body to carry out each of their functions, such as controlling which genes are "turned on" aka expressed.

As for the potential biotin hair growth benefits, "In recent decades, it has been suggested that supplemental biotin can also play a role in hair growth by stimulating keratin production and increasing the growth rate of hair follicles," says Dr. Henry. Along with supplements, you can also absorb biotin through food sources, such as eggs and red meat, as Shape previously reported.

Is Taking Biotin for Hair Growth Effective?

Alas, "although Biotin has gained massive popularity, there is limited research that proves supplemental biotin's efficacy on hair strengthening and growth," says Dr. Henry. That said, "some studies have shown how biotin supplements significantly increased hair growth in individuals with temporary hair loss." In one such study published in the Journal of Clinical and Aesthetic Dermatology, women experiencing temporary hair thinning who took a supplement containing biotin over six months had a significantly greater increase in terminal (i.e., thick) hairs compared to a control group. Note that the study had a small sample size of 15 participants, so it's not a guarantee that taking biotin can increase hair growth.

Even assuming that taking biotin for hair growth is effective, it may be less helpful or even useless if you aren't deficient in the vitamin. "Vitamin B7, or biotin, deficiency is relatively rare with around [1 in 140,000 people] having profound congenital biotinidase deficiency," says Dr. Henry. (FYI, profound biotinidase deficiency is a genetic disorder that occurs when your body is unable to recycle biotin.) "...Research has concluded that while not as effective in healthy individuals, biotin supplements have a role in stimulating hair growth in biotin-deficient patients."

Signs of low biotin levels include hair loss and developing a scaly texture to your skin, and if you suspect that you're deficient in biotin, a blood test can confirm whether that's the case, says Dr. Henry.

How to Safely Take Biotin for Hair Growth

Convinced you'd like to give the supplements a try? Rather than Googling "best biotin for hair growth" and adding the first product you set eyes on to your cart, "it's essential to choose biotin, or any other supplement, that has been recommended by a certified nutritionist or a doctor," says Dr. Henry. As a rule, checking with your doctor for personalized advice before incorporating any supplement is a smart move.

You also want to avoid taking too much biotin, which may have side effects. "Although no serious side effects have been reported, ingesting too much biotin may cause gastrointestinal changes, such as diarrhea or constipation," says Dr. Henry. "...The right dose of biotin supplement may depend on the individual's age, however, the daily dose should not exceed 100 micrograms." Additionally, taking biotin can interfere with the results of various blood tests, she notes. With that in mind, it's important to communicate with your doctor if you're taking biotin and have an upcoming blood test.

Whether or not biotin supplements deserve their status as a popular hair growth solution is still under question. If you decide to give it a try regardless, just make sure to do your homework before deciding which biotin supplement to take.

Have a hair health question you want answered? Send your Q to hairhotline@shape.com for a chance to have it featured in a future installment of Hair Health Hotline.