b.i.d. is an abbreviation used in writing prescriptions or instructions for taking medications. It is from the Latin bis in die and means twice a day.
We sometimes see b.i.d. when discussing Migraine and headache medications.
You can read more about Migraine and headache medications in these sections of our site:
For more terms, see our Migraine and Headache Glossary.
Medical review by John Claude Krusz, PhD, MD.