According to the pamphlet that accompanies Viagra, the recommendation is to take the pill either one hour before the intended sex act on an empty stomach, or two hours after eating and up to four hours before sex. This will avoid a delay in its effectiveness. It is also suggested to take Viagra with a glass of water, or with skim milk. A light snack is not contraindicated. Doctors advise keeping in mind that taking a dose with whole milk or heavy food may have an impact on its effectiveness.