The most common side effects of VIAGRA: headache; flushing; upset stomach; abnormal vision, such as changes in color vision such as having a blue color tinge and blurred vision; stuffy or runny nose; back pain; muscle pain; nausea; dizziness; rash. Self-esteem, confidence, and relationships in men with erectile dysfunction treated with sildenafil citrate: Pooled analysis of two double-blind, placebo-controlled trials. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. Kidney disease that needs to be treated with dialysis. Data shared with Viatris will be aggregated and de-identified; it will be combined with data related to other Savings Offer redemptions and will not identify you Viatris reserves the right to rescind, revoke, or amend this Savings Offer without notice No membership fees. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. These medicines are called PDE5 inhibitors.Viagra Connect is the first erectile dysfunction medicine in the UK to be sold without the need for a prescription, which means you can order Viagra Connect discreetly online or buy in-store without the need to make an appointment with your GP. How does Viagra Connect work? 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 helps to maintain an erection. Before taking Viagra, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or supplements you take.