Sildenafil Citrate — What It Does and Why People Use It
Sildenafil citrate is the active ingredient in well-known drugs for erectile dysfunction (ED) and is also used in some cases of pulmonary arterial hypertension. If you’re considering it, this page gives the practical basics: how it works, typical doses, common side effects, important drug interactions, and simple tips for buying safely online.
How sildenafil works and typical dosing
Sildenafil relaxes blood vessels so blood can flow more easily to certain areas of the body. For ED, people usually take a single oral dose 30–60 minutes before sexual activity. Typical starting doses are 25–50 mg; doctors may increase to 100 mg if needed or lower it if side effects appear. Don’t take more than one dose in 24 hours.
When used for pulmonary arterial hypertension, dosing and timing differ and a doctor will set the proper schedule. If you have liver or kidney problems, or are over 65, clinicians often recommend lower doses and slower adjustments.
Side effects, warning signs, and interactions
Common side effects are headache, flushing, indigestion, nasal congestion, and mild vision changes (like blue tint). These usually go away on their own. Stop the medicine and get urgent care if you experience chest pain, sudden hearing loss, sudden severe vision loss, or a painful erection lasting more than four hours (priapism).
Do not take sildenafil with nitrates (often prescribed for chest pain). That combination can cause a dangerous drop in blood pressure. Avoid taking it with strong inhibitors of CYP3A4—like some azole antifungals and HIV protease inhibitors—unless your doctor adjusts the dose. Grapefruit can raise drug levels and increase side effects. Moderate alcohol is usually okay, but heavy drinking raises the risk of dizziness and low blood pressure.
If you take alpha-blockers for prostate problems or blood pressure meds, start on a low sildenafil dose and get medical advice before combining them. Always tell your prescriber about all medicines and supplements you use.
Practical buying tips
Sildenafil needs a prescription in many countries. If you see a pharmacy selling it without a prescription, be cautious. Look for clear contact info, a licensed pharmacist on staff, HTTPS security, and verifiable business details. Avoid sites that offer huge discounts, lifetime supplies, or substitute brand names with no clear ingredients listed. Check reviews but verify claims through trusted sources.
If you can, use local pharmacies or licensed online pharmacies that require a prescription and offer pharmacist consultation. That reduces the chance of fake, expired, or incorrect-strength products. When in doubt, ask your healthcare provider for trusted pharmacy recommendations.
Want short, practical help choosing a dose or checking an interaction? Save this page and bring the details to your prescriber—having your meds and medical history on hand makes the conversation faster and safer.
