Biotin (Vitamin B7)
B vitamin supporting hair, skin, and nail keratin production.
By Suplagen Team · Updated
What it is
Biotin (vitamin B7) is a water-soluble B vitamin that serves as a cofactor for carboxylase enzymes involved in keratin production and energy metabolism.
How it works
Cofactor for carboxylase enzymes (ACC, PCC, MCC, PC); supports fatty acid synthesis and amino acid metabolism critical for keratin.
What the evidence says
Evidence for hair/nail benefits mainly in deficiency states; limited evidence for benefit in non-deficient individuals.
How much to take
The catalog range is 2,500 to 5,000 mcg daily, with a 10,000 mcg ceiling. That's far above dietary needs, and the honest caveat comes with it: biotin's hair and nail benefits show up mainly in people who are deficient, which is uncommon.
If you're not deficient, the evidence for extra benefit is limited. Start at 2,500 mcg if you're going to run the experiment, and judge it at 8 to 12 weeks, because hair and nails grow slowly.
When and how to take it
Take it with food, in the morning. There's no absorption trick and no supplement it clashes with.
The one rule that matters is about blood tests: high-dose biotin distorts thyroid, troponin, and other lab results. Stop it 48 to 72 hours before any blood work, and tell whoever orders the test.
Who should skip it
Biotin is safe in pregnancy and well tolerated. The caution is procedural rather than physical: anyone with upcoming labs, a heart workup, or thyroid monitoring should pause it first, because a false troponin or thyroid result is a real clinical problem. It also interacts mildly with anticonvulsants.
Safety Notes
- IMPORTANT: High-dose biotin (>5000 mcg) can cause false results on troponin, thyroid, and other lab tests. Discontinue 48-72h before blood work.
- anticonvulsants: Some anticonvulsants deplete biotin; supplementation may be beneficial.
Common questions
How much biotin should I take a day?
2,500 to 5,000 mcg is the catalog range, and the ceiling is 10,000 mcg. More does nothing extra for hair or nails unless you were deficient to begin with.
Should I take biotin in the morning or at night?
Morning with food, but only for habit-building convenience. Biotin has no timing effect; consistency is the whole game, so attach it to a meal you never skip.
Do I need to stop biotin before blood work?
Yes. Stop 48 to 72 hours before any blood test. High-dose biotin can cause false results on thyroid and troponin panels, which can send a diagnosis in the wrong direction.