Biotin (low-dose, deficiency)

Tier 2 — promising · Hair · Nails · Metabolism

At physiological doses (30–100 mcg), biotin corrects true deficiency symptoms like hair loss, brittle nails, and skin rash. Different from high-dose biotin (10,000+ mcg), which lacks evidence for hair growth in non-deficient people and can falsify lab tests.

Dose: 30–100 mcg/day for deficiency; stop 48 hours before blood tests to avoid interference