4 The half life of a medication is the amount of time for half of the drug to be eliminated from the body The half life of Advil or ibuprofen is represented by the equation R M 0 5 where R is the amount of Advil remaining in the body M is the initial dosage and t is time in hours These numbers are made up Consult your Dr before taking any medication a A 200 milligram dosage of Advil is taken at 1 00 pm How many milligrams of the medication will remain in the body at 6 00 pm AMA Advil See new warningsinformation b If a 200 milligram dosage of Advil is taken how many milligrams of the medication will remain in the body 12 hours later