Click here for an email preview. Imagine if nine out of ten Advil gave you diarrhea, you know? There is a problem with information submitted for this request. Initial doses of sildenafil should not exceed 25 mg. Because it is a PDE-5 inhibitor, it functions effectively. If you feel any unease or not well during the medication then stop the medication and visit the doctor immediately. · For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual intercourse. . Take sildenafil at least 30 minutes, but no more than 4 hours, before sexual activity (1 hour before is the most effective). Do not take more than once daily. A high- fat meal may .  · Does Kamagra Oral Jelly Work for ED? While there’s relatively little research on Kamagra itself, there’s a ton of established research that concludes that sildenafil or .