When talking about fertility treatments, injectables refer to drugs taken via injection, for example, gonadotropins, GnRH agonists and progesterone in oil. There are two kinds of injectables: intramuscular and subcutaneous. Intramuscular injections must be injected in muscle tissue, usually your buttocks.
Subcutaneous injections are shots that are injected in to the fatty tissue below the skin. For fertility treatments, these are usually given an inch below the belly button or in to the fatty tissue of the thighs.
As opposed to fertility drugs taken by mouth, injectables are typically stronger medications and come with a higher risk of multiple pregnancy and ovarian hyperstimulation syndrome.Source:
Medications for Inducing Ovulation: A Guide for Patients. American Society of Reproductive Medicine. Accessed February 3, 2008. http://asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/ovulation_drugs.pdf