Caverject and Invicorp contain different kinds of drugs. Alprostadil is the main ingredient in Caverject, and Invicorp contains both aviptadil and phentolamine mesilate. Both of them are injected into the penis and can provide results in a very short time.
The way they work is slightly different: aviptadil is a peptide, which means it works in the intestine; and phentolamine is an adrenergic antagonist which works in the nervous system. Alprostadil is a prostaglandin, which has muscle contracting qualities. In various ways, these help to increase blood flow to the penis when used in ED, enabling better erections.