As a result, more blood can flow into the penis when sexually stimulated, leading to a firmer and longer-lasting erection. Alcohol can impair sexual performance and reduce the effectiveness of the medication. These are commonly prescribed for an enlarged prostate or male pattern baldness. However, if you experience any severe or persistent side effects, it’s crucial to seek medical attention. Your healthcare provider will determine the most suitable dosage for you based on factors such as your overall health, severity of ED, and response to the medication. However, it’s important to note that individual responses may vary, so it’s advisable to consult with a healthcare professional for personalized guidance.In fact, in some countries, generic Viagra is available without a prescription, making it even more accessible to those in need. Generic viagra is available in various strengths, including 25mg, 50mg, and mg. Generic viagra has been found to be effective in approximately % of men with ED. Last updated: June 14, If you’re looking for a less costly Viagra, you might want to ask your doctor about sildenafil. It’s the active ingredient in both branded Viagra and the drug. Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or alcohol. Its effects often last for 4 to 5 hours. It might work longer if you have mild to moderate erectile dysfunction. Vardenafil.