The maximum recommended dosing frequency is once a day. The most common side effects with Viagra are headache, flushing, dyspepsia indigestion , visual disorders, including visual colour distortion and blurred vision, nasal congestion blocked nose , dizziness, nausea and hot flushes. What benefit has Viagra shown during the studies? Read More They range from two zones in the medieval town of Carcassone to twelve in the heavily Muslim town of Marseilles, with hardly a town in France lacking in its ZUS. Viagra increases blood flow and it helps a lot.The study for efficacy of Viagra in women which is currently in progress is a study for sexual enhancement for women. So it has nothing to do with MS. Viagra increases blood flow . Can I buy generic Viagra over the counter or do I need a prescription? In the U.S. and most other countries, generic Viagra is only available with a prescription. En France, il est obligatoire d’avoir une ordonnance valide pour retirer du Viagra dans une pharmacie. Les règles ne changent pas dans une pharmacie en ligne. Vous vous mettez .