What is the difference in measurements of mg and mcg is pills?

Mcg (micrograms) are 1000 times smaller than mg (milligrams). For example, a drug that has a strength of .075 mg is equivalent to 75 mcg. Many drugs are measured in mg, but some are in mcg. Always be aware of what you are taking - make sure you have been given the correct strength prescribed by the doctor or that the doctor wrote down the correct strength on the prescription. A difference in a few decimal points can mean a major over/underdose! Hope this helps!