Suboxone is an FDA-Approved Medication to treat opioids. Suboxone 2 mg is the lowest variant dose of suboxone. It contains Lactose. Suboxone has little effect when taken by mouth. Pregnant women can not take suboxone because it shows life withdrawal symptoms in newborns. Suboxone works instantly like 20 minutes after the first dose. Headache is a common side effect of Suboxone.