This increase in blood flow results in a firmer, longer-lasting erection. Online pharmacies also may not fill short-term prescriptions, such as those for antibiotics. This is important for your overall health and safety, as certain medications can negatively interact with each other or cause existing conditions to worsen. Online pharmacies can be broadly categorized as: Mail-order pharmacies are operated by pharmacy benefits managers PBMs on behalf of health insurers or providers. Both options require valid medical documentation, but some online services only require a health questionnaire to be filled out and reviewed for approval—meaning no face-to-face video interaction is needed.sildenafil citrate or viagra Savings, Coupons and Information. | SILDENAFIL (sil DEN a fil) treats erectile dysfunction (ED). It works by increasing blood flow to the penis, which . $ (save %) local_offer_outlined Avg retail price $ medication_outlined Availability Available See GoodRx coupons warning Are you looking . Cart. Transfer your prescription for Sildenafil (Generic for Viagra, Oral Tablet) on Amazon Pharmacy. FREE SHIPPING for Prime members.