What are the possible side effects of Vitamin B2 (Riboflavin)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Riboflavin may cause your urine to become a yellow-orange color. This effect is harmless.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.