The Best Biotin Supplements for Hair Growth

Biotin goes by two other names—vitamin B7 and vitamin H—and plays a role in the production of keratin, a protein essential for healthy skin, hair, and nails. It’s a water-soluble vitamin, meaning it doesn’t build up in your body; rather, you excrete the excess through urine. The recommended daily intake of biotin is 30 micrograms per day, according to the National Institutes of Health (NIH), and we naturally hit that mark through our diets—most healthy adults get about 35-70 mcg per day, Woodson says. Some biotin-rich foods include meat (and organ meats), fish, eggs, nuts, seeds, and sweet potatoes.

Benefits of biotin (vitamin B7)

• Glucose: Biotin helps to process carbohydrates (glucose), fats, and proteins and convert them into energy for the body to use, says Dr. Garshick.
• Fatty acids: Biotin is necessary for the creation of fatty acids, which are essential for cell maintenance and energy storage, says Woodson.
• Amino acids: Biotin helps deconstruct amino acids, a.k.a. the building blocks of proteins. Amino acids are repurposed to create energy or support other metabolic needs, says Woodson.

Benefits of biotin supplements

• Hair growth: For people who have thinning hair because of a biotin deficiency, some studies suggest that biotin supplementation can reduce hair loss and stimulate hair regrowth. “Most people typically see significant improvements after consistent use for three months or longer,” Woodson says.
• Nail and cuticle health: Supplementing with biotin may help strengthen weak nails, as some studies show taking 2.5 mg per day can help with nail thickness. But the evidence isn’t crystal clear. The studies out there on using biotin for brittle nails are very small, and the researchers didn’t use placebo groups or check participants’ initial levels of biotin.

Some people report mild digestive symptoms, like an upset stomach, when taking biotin supplements. Yet, even in high doses, there isn’t any evidence that suggests biotin supplements are harmful or toxic, Woodson says. That’s because biotin is water-soluble and the excess gets excreted through urine, so it doesn’t build up in the body at toxic levels.

Still, you may not be in the clear, at least not on paper. Biotin may interfere with certain laboratory test results including thyroid and troponin levels (a marker used to detect heart attacks), according to the FDA. If you’re getting lab tests done, make sure to stop taking biotin beforehand and always remember to tell your doctor about all medications, including supplements (as well as multivitamins) you’re taking, Dr. Garshick says.

Research shows that taking 5,000 mcg (5 mg) of biotin daily may help treat hair loss caused by a biotin deficiency. But remember, a biotin deficiency is pretty rare. And there isn’t much scientific evidence that supports biotin supplementation significantly improving hair health for those of us without a biotin deficiency.

“Generally speaking, the only people who should absolutely be taking biotin supplements are those who are deficient, which is generally rare,” Dr. Garshick says. “That said, although there isn’t much clinical evidence, if people are looking to try something for their hair and nails, they can consider it and if they are noticing an improvement, it is fine to continue with it.”