If you’re eager to grow out your hair, chances are you’ve been served up a supplement on Instagram or through a Google search that contains biotin. Biotin, a B-vitamin, is found in foods like eggs, salmon, sweet potatoes, and almonds and is often a featured ingredient in beauty supplements as a means to help with hair loss and brittle nails.
With searches like “how much biotin should I take for hair loss,” “best biotin for hair growth,” and “too much biotin side effects?” up 100 percent, 70 percent, and 90 percent respectively in the last 7 months, plus “how much biotin should I take daily?” becoming a new breakout search on Google in 2021, it begs the question: Do we need supplemental biotin? And how can it affect your health?
Do we need biotin?
Most people don’t need biotin supplementally. Though exact figures aren’t available, the National Institutes of Health reports that biotin deficiency is rare in healthy adults eating a balanced diet. “Generally, biotin is found readily available in most diets, so meat, fish, eggs, seeds, nuts, and vegetables, like sweet potato, spinach — all very common sources of biotin,” says Dhaval Bhanusali, a board-certified dermatologist based in New York City.
“In different countries, there are different diets. There are a lot of things that people definitely have more nutritional deficiencies in,” says Nancy Samolitis, a board-certified dermatologist in Los Angeles. “With our diet here, even if you’re a vegan, there are options. There are a lot of vitamins that people are truly deficient in, and biotin is usually not one of them.”
That’s due largely in part to the recommended daily amount (RDA) of biotin. According to Bhanusali, it depends on the source you’re getting the RDA from, but typically between 30 and 100 micrograms — not milligrams — a day is sufficient. The National Institutes of Health (NIH) reports a whole cooked egg provides 10 micrograms per serving, or 33 percent of the daily value, for example.
Does biotin actually help the hair grow?
Hair supplements promising “longer, stronger” hair often contain more than the typical RDA of biotin. But having an excess of biotin doesn’t necessarily provide hair with the benefits you may be seeking. Bhanusali, Samolitis, and board-certified dermatologist Shanthi Colaco all say that biotin is water-soluble, meaning what your body doesn’t use, you urinate out. Although high doses are unnecessary, it’s considered harmless if you intake more than the RDA.