Certain medications, such as insulin, can only be administered by injection. Depending on the formulation and the type of medication, injectable medications can be given by several routes. They can be given through direct injection into a vein (known as intravenous, or IV injection), injection into a muscle (known as intramuscular, or IM injection), or injection directly under the skin – a procedure known as subcutaneous (SC orSQ) injection. It is very important that you understand how your pet’s injectable medication needs to be given; for example, if you accidentally give a medication intravenously instead of subcutaneously, complications can result. Most injectable medications given at home are intended to be given subcutaneously.