1 cc (cubic centimeter) is equal to 1 ml (millilitre), it measures volume. For example if a bottle contains 10 ml of liquid, this corresponds to 10 ccs.
1 mg (milligram) measures the dose of a drug, 1 mg is equal to 1/1000 of a gram.
1 mcg (microgram) is equal to 1/1000 of a milligram.
1 international unit (IU) is also used to measure the dose of a preparation for hormones for example.
