women happy viagra professional work viagra prescription drug used treat erection difficulties erectile dysfunction ed since first became available 1998 prescription drug viagra helped 16 million men around world improve sex lives amazing 9 tablets dispensed every second worldwide therapy prescription drug erectile dysfunction studied much amount real world experience viagra since launch wonder 600 000 doctors chosen prescription drug viagra patients ed fact taken correctly viagra works men studies show works 4 5 men versus 1 4 sugar pill viagra improves erections men matter long ed caused often old treatmentis effective refund every unopened pack send back immediately refund account read order remove email