Vitaros is a topical cream used to treat erectile dysfunction. It contains the active ingredient Alprostadil which is a prostaglandin (PGE-1) and can also be found in other products such as Caverject and MUSE. Vitaros cream is absorbed into the skin and acts by dilating (opening) the blood vessels that control the movement of blood into the penis. It also helps blood vessels which let blood out of the penis to constrict (tighten) and thus keeping blood in the penis enabling it to stay erect long enough for intercourse. Vitaros is unique within the line of alprostadil products as it gets to work by being applied to the opening of the urethra at the tip of the penis, via a plunger (provided in the pack). The effects of the treatment are noticeable within 5-30 minutes, and can last for 1-2 hours afterwards. All the other alprostadil products have to injected thus making Vitaros relatively non-invasive to use. Vitaros is particularly useful for patients that find it difficult to swallow tablets or experience any intolerable side effects from oral PDE-5 inhibitors. Vitaros causes less known side effects, has less interactions and is less affected by food and drink than the oral PDE-5 inhibitors. It is also suitable for patients who also take nitrates for angina / heart disease, who cannot safely take oral PDE-5 inhibitors.