What are the side effects of bilberry?

What are the possible side effects of bilberry ()? Although rare, allergic reactions to bilberry may occur. Stop taking bilberry and seek emergency medical attention if you experience symptoms of a serious allergic reaction including difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives.Other less serious side effects have not been reported, although they may occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.