Some links on this site are paid links: if you buy through them, we earn a commission at no extra cost to you. This page has no paid links. Affiliate disclosure.
No tolerable upper intake level (UL) has been set for biotin. The National Academies found too little data to set one for biotin. Health Canada, which uses the same values, adds that this "does not mean that there is no potential for adverse effects resulting from high intakes." That doesn’t make any amount safe for everyone: talk to your doctor about high doses.
Take several supplements? Add them all up in the Supplement Checker: it shows your biotin total next to the nutrients that do have a limit.
How much Biotin you need
| Age | Males | Females | Pregnancy | Breastfeeding |
|---|---|---|---|---|
| Birth to 6 months | 5 mcg* | 5 mcg* | – | – |
| 7-12 months | 6 mcg* | 6 mcg* | – | – |
| 1-3 years | 8 mcg* | 8 mcg* | – | – |
| 4-8 years | 12 mcg* | 12 mcg* | – | – |
| 9-13 years | 20 mcg* | 20 mcg* | – | – |
| 14-18 years | 25 mcg* | 25 mcg* | 30 mcg* | 35 mcg* |
| 19-30 years | 30 mcg* | 30 mcg* | 30 mcg* | 35 mcg* |
| 31-50 years | 30 mcg* | 30 mcg* | 30 mcg* | 35 mcg* |
| 51-70 years | 30 mcg* | 30 mcg* | – | – |
| 71+ years | 30 mcg* | 30 mcg* | – | – |
* Adequate Intake (AI): the amount set when there isn’t enough evidence for an RDA.
What counts toward the Biotin limit
No upper limit (UL) has been set for biotin.
What happens with too much Biotin
The National Academies' 1998 DRI report says "No reported adverse effects of biotin in humans or animals were found", and that toxicity has not been reported in patients treated with daily doses up to 200 mg orally. It still judged the data insufficient to set a UL. Health Canada adds that the lack of a UL "does not mean that there is no potential for adverse effects resulting from high intakes."
Sources: Health Canada, Dietary Reference Intakes tables (the joint U.S.-Canada values); National Academies, Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998); National Academies, Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998). Limits checked November 8, 2026. More from the NIH: Office of Dietary Supplements Biotin fact sheet.
If you think you or a child took too much of a supplement, call Poison Control at 1-800-222-1222 (U.S., free, 24 hours) or use poison.org. In an emergency, call 911.
General information, not medical advice. Your doctor may recommend a different amount, for example to treat a deficiency. Talk to your doctor or pharmacist before you start, stop or change a supplement, especially if you are pregnant, nursing, take medication or have a medical condition.