Compounding is the pharmaceutical science of making a medication and an individual patient compatible.
In this day and age most medications are mass produced; that is they are made in bulk by large pharmaceutical companies for thousands of people who at some time may need to have a prescription filled. In many instances mass produced medications will work just fine for you or a loved one who has fallen ill. However, in some instances a mass produced medication will not work or be tolerated. Something about the medication is not compatible with your unique physiological makeup.
Compounding allows a specially trained pharmacist to make a medication and a patient (human or animal) compatible. This is done by taking into consideration the patient's unique needs and symptoms.
A compounding pharmacist uses raw chemicals, powders, liquids, and special equipment to make each medication, one at a time. This results in a customized medication made by a pharmacist, according to a doctor's directions, to meet an individual patient need.