Milligram/ˈmɪliɡræm/ Definition 1 of 1Pro Tip 1/3Medical Dosage Milligram is highly used in medicine to measure precise drug dosages. The label says to take 200 milligrams of ibuprofen every 8 hours. Pro Tip 2/3Nutritional Labels Food and supplement labels often list micronutrient amounts in milligrams. This cereal contains 150 milligrams of iron per serving. Pro Tip 3/3Precision Importance Use milligram when precision matters, like in scientific measurements. The solution requires 5 milligrams of this chemical.