You can take this medicine with or without food 30 minutes before sex, depending on the dose. Severe liver disease. People with heart conditions should never take ED medications without consulting a doctor. Your health information should remain between your provider and yourself. It’s available in 50 mg, mg, and mg tablets.Best Low Cost: GoodRx Fastest Delivery: Blink Health: Sesame Sign Up Now Key Specs Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions Medical . 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 .