Sildenafil is the active ingredient made well known by Viagra and is also available in authorised generic medicines. It is used for erectile dysfunction in adult men when obtaining or maintaining an erection is difficult.
How sildenafil works
During sexual stimulation, the body releases signals that relax blood vessels in the penis. Sildenafil slows the breakdown of one of these signals, cGMP, which supports increased blood flow. It is not an aphrodisiac and does not work without arousal.
Food, alcohol and expectations
A high-fat meal may delay the start of the effect. Large amounts of alcohol can make an erection more difficult and increase some side effects. The response should not be judged like an instant switch: stimulation, context and correct use all matter.
Common side effects
- headache;
- facial flushing;
- indigestion;
- nasal congestion;
- dizziness or temporary changes in vision.
Not everyone experiences these effects. Contact a doctor or pharmacist if a symptom is severe, unusual or persistent.
When sildenafil may not be suitable
Sildenafil must not be combined with nitrates used for angina and requires caution with some cardiovascular treatments. Tell a clinician about all medicines and relevant health conditions, particularly heart disease, very low blood pressure, liver or kidney disease and previous serious vision problems.
Warning signs
Chest pain, sudden loss of vision or hearing and a painful erection lasting longer than four hours require urgent medical attention. If chest pain occurs after sildenafil, do not use nitrates to treat it; tell the medical team what you have taken.
Related guides: sildenafil, tadalafil, vardenafil and avanafil compared and generic and brand-name medicines.
