Viagra Helps You Recover Faster After Orgasm Another common belief about Viagra is that it can reduce your refractory period — the amount of time that needs to pass for a man to recover after having sex and reaching orgasm. It works for up to 36 hours. Follow the manufacturer’s directions to use and clean the oral syringe. You can take this medicine with or without food 30 minutes before sex, depending on the dose. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. International Journal of Urology.Generic Viagra (sildenafil) is available as a , , , and milligram (mg) pill and in liquid form. It’s meant to be taken as needed — about an hour before sex — but shouldn’t be.  · Maximum dose: 20 mg orally three times a day. Injection: Initial dose: or 10 mg IV bolus three times a day. Comments: No greater efficacy was achieved with oral doses higher than the maximum recommended dose. A 10 mg injection dose is predicted to provide pharmacological effect equivalent to the 20 mg oral dose.  · VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or mg of sildenafil. Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR on the other to indicate the dosage strengths. 4. Contraindications.