Daily How Much

A two-tablet daily serving of Viviscal 4D lists 3,000 mcg of biotin on its Supplement Facts panel.

Most hair-growth capsules in this brand list 3,000 mcg of biotin per 4-capsule serving, but check your bottle for updates.

One cooked whole egg provides 10 mcg of biotin, which is about one-third of the Daily Value.

Most adults do fine with 30–100 mcg daily, while high-dose pills (1,000–10,000 mcg) rarely change hair unless a true deficiency is in play.

Most adults do well near 30 mcg daily from food, while higher supplement doses can be useful in select cases and can skew lab tests.

Biotin can help hair only when intake is low; for most adults, food plus an AI of 30 mcg/day is plenty, and high-dose pills often add little.

Most brittle-nail studies used 2,500 mcg daily; adults already have an intake target of 30 mcg/day from food and supplements.

Most adults who use biotin for hair take 30–100 mcg daily; higher doses rarely help unless a lab test shows low levels.

Most adults meet normal biotin needs at 30 mcg per day; bigger doses seldom change hair growth unless low biotin status is present.

Free biotin is absorbed well, yet after your body’s needs are met, extra biotin mostly leaves through urine.