What is biotin?
Biotin is a water-soluble B vitamin involved in normal metabolism. Because keratin formation depends on normal nutrient and amino-acid metabolism, biotin is often included in hair, skin and nail formulas.
Can biotin make hair grow?
Biotin deficiency can be associated with thinning hair, but deficiency is uncommon. Evidence that extra high-dose biotin improves hair in people who are not deficient is limited.
Food sources
Biotin is found in foods such as cooked eggs, meat and fish, nuts and seeds, legumes, soy foods, some vegetables and whole grains.
Important safety point
High-dose biotin can interfere with certain laboratory tests, including some thyroid, hormone and cardiac tests. Tell your doctor and laboratory staff if you take a biotin-containing supplement before blood tests.
Choosing a hair-nutrition formula
Look for balanced formulation, clear labelling, sensible doses and responsible claims rather than simply the highest biotin number.
Frequently asked questions
Are biotin and vitamin B7 the same?
Yes. Biotin is commonly called vitamin B7.
Is a higher dose always better?
No. Evidence does not show that ever-higher doses improve hair in people who are not deficient, and high doses can interfere with lab tests.
Does hair shedding prove biotin deficiency?
No. Hair shedding has many possible causes, including genetics, stress, medical conditions, medication, other nutrient deficiencies and scalp problems.