An intravenous injection is a medical procedure in which a medication or substance is directly sent into the vein and bloodstream through a tube or needle. This is one of the quickest options to get a medication into the body. During this process, a doctor will insert an IV catheter, a thin plastic tube, into the vein. Through this tube, multiple dosages of medications can be given into the body. An intravenous injection can be done at home, but it should be implemented by a healthcare provider to ensure safety and reduce the risks of possible complications.