There are three ways to inject peptides: intravenous, subcutaneous, and intramuscular.
With intravenous injection, a doctor would have to locate a vein on your body to inject the peptide. In an intramuscular injection, the peptide medication is directly administered deep into the muscle for quicker absorption into the bloodstream. However, the subcutaneous method is considered the most effective as the injection targets larger tissues such as the abdominal region to disperse peptide medication throughout the body effectively.