Constipation, diarrhea, or upset stomach may occur. These effects are usually temporary and may disappear as your body adjusts to this medication. If any of these effects persist or worsen, contact your doctor or pharmacist promptly.

What are the side effects of taking biotin?

Biotin supplements can cause problems if you take too much. Side effects can include skin rashes, digestive upset, problems with insulin release, and kidney problems. As with any supplement, the safety of long-term or high-dose use isn't known.

Does biotin affect bowel movements?

Common side effects may include upset stomach or diarrhea.