Biotin (B7)
Biotin
Vitamins. Modern nutrition.
Also called Vitamin B7, Vitamin H, Coenzyme R
Pinyin: shēngwùsù
Spanish: Biotina
Can skew blood testsA B vitamin the body uses to break down fats, sugars and protein for energy.
Did you know? Raw egg white contains avidin, a protein that grabs biotin and blocks its absorption. Cooking breaks avidin down, which is why cooked eggs are fine.
What it may help, and how strong the proof is
- Skin. A few small trials found that biotin may thicken brittle nails. The trials are small and short, so the proof is weak.Early proof
- Hair & nails. Biotin is sold for hair growth. True biotin deficiency, which is rare, can cause hair thinning, and fixing it helps. In people who get enough, biotin pills have not been shown to regrow hair.Not supported
Parts of the body
Traditional use
Biotin has no herbal tradition. It was once called vitamin H, from the German word Haut (skin), after animals that lacked it developed skin problems.
How it is classified
How people take it
Adults need 30 mcg a day, the adequate intake (AI), which is used when no RDA is set. No upper limit has been set. Many hair and skin pills contain 5,000 to 10,000 mcg, far above the need.
Food, capsule and tablet.
Where to get it
Good sources are cooked egg yolk, beef liver, salmon, pork, sunflower seeds, almonds, sweet potato, avocado, and mushrooms. Gut bacteria also make some biotin. Pills come as capsules, tablets and gummies.
Be careful
Biotin is safe at normal doses. Very high doses can make lab tests for thyroid, heart and hormone levels read falsely high or low, which can lead to wrong diagnoses. Tell your lab if you take biotin, and stop before tests if your doctor advises it.
Avoid if: before lab tests (stop if advised).
Mixing with other things
- Works well together
Often sold together in hair and nail blends. There is no proof that they work better as a pair.
- Worth knowingAntibiotics (doxycycline, Cipro and similar)
Long antibiotic courses can reduce the biotin made by gut bacteria. For most people the effect is small.
The honest take
Biotin is a real nutrient, and true deficiency is rare. Hair and nail claims are mostly marketing for people who already get enough. The bigger real risk is wrong lab results from high doses.