Viagra, known generically as sildenafil, is a widely recognized medication primarily used to treat erectile dysfunction (ED) and, in some cases, pulmonary arterial hypertension. Viagra works by inhibiting an enzyme called phosphodiesterase type 5 (PDE5). This action helps to relax blood vessels and increase blood flow to certain areas of the body, notably the penis.

 

When sexually stimulated, this increased blood flow facilitates the achievement and maintenance of an erection. It is important to note that Viagra does not cause an erection without sexual arousal. Viagra is available in various dosages, commonly 25mg, 50mg, and 100mg. The appropriate dosage is determined by a healthcare provider based on individual needs and medical history.

 

The medication is typically taken about 30 to 60 minutes before sexual activity, and its effects can last for up to four hours. However, it should not be taken more than once a day. Common side effects of Viagra include headaches, flushing, indigestion, nasal congestion, dizziness, and visual disturbances.