Sildenafil — what it does and how to use it safely

Wondering if sildenafil is right for you? Sildenafil (brand names include Viagra and Revatio) relaxes blood vessels to help with erectile dysfunction (ED) and certain lung conditions (pulmonary arterial hypertension). It works fast for many men and can be a reliable option when used correctly.

Here’s practical, straight talk on doses, timing, risks, and how to buy sildenafil without getting burned.

How to take sildenafil and common doses

For erectile dysfunction: common doses are 25 mg, 50 mg, and 100 mg. Most people start at 50 mg taken about 30–60 minutes before sex. If that works well, you might stay at that dose; if it’s too strong or you get side effects, try 25 mg; if not effective, talk to your doctor about 100 mg.

For pulmonary arterial hypertension (PAH): the typical dose is 20 mg three times daily (Revatio). Don’t mix dosing schedules between conditions without medical advice.

Take sildenafil on an empty stomach for faster effect. A heavy, fatty meal can delay how quickly it works. Avoid alcohol in excess — it can blunt response and raise side-effect risk.

Side effects, interactions, and danger signs

Common side effects are headache, flushing, nasal congestion, indigestion, and mild vision changes (blue tint or sensitivity). Most fade within a few hours.

Red flags you must avoid: nitrates (for chest pain) and organic nitrates. Combining sildenafil with nitrates can cause a dangerous drop in blood pressure. If you take alpha-blockers, certain blood-pressure meds, or some HIV and antifungal drugs, dose adjustments or timing changes may be needed. Tell your doctor about every medication you take.

Seek immediate help for priapism — a painful erection lasting more than four hours — and get urgent care if you feel faint, very dizzy, or have chest pain after taking sildenafil.

Older adults or people with serious heart, liver, or kidney disease need personalized dosing. Always check with a clinician if you have any major health issues.

Thinking of buying sildenafil online? A few quick rules will keep you safer:

• Only buy from pharmacies that require a prescription and show a licensed pharmacist contact.
• Check for secure site indicators (HTTPS), clear company info, and real customer reviews.
• A price that’s way lower than everywhere else is a red flag for counterfeit pills.
• Be cautious with sites that offer quick quizzes instead of a real prescription from a doctor you see or speak with live.

If you’re curious about alternatives, there are other PDE5 inhibitors like tadalafil (Cialis) and vardenafil (Levitra). Each has different timing and duration—talk with your healthcare provider to find the best fit.

Want to learn more or check specific online pharmacies? Our site has reviews and guides on buying meds safely. If you’re unsure about interactions or the right dose, a quick consult with a pharmacist or your doctor will save trouble down the road.