Most online pharmacies do not prescribe or refill controlled substances, like Adderall, Xanax, or oxycodone. The products discussed in this site may have different product labeling in different countries. 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. If approved, the provider will issue a prescription. Those with a history of blood pressure or heart issues, hormonal imbalances, mental health issues, and diabetes should consult their doctor before trying PDE5 inhibitors.If you’re holding out for a generic version of branded Viagra, you won’t have to wait much longer. Teva Pharmaceuticals plans to release its generic of the “little blue pill” as early as. CHOOSE BRAND-NAME VIAGRA The original little blue pill prescribed by doctors for over 20 years Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring Learn More IF YOU CHOOSE BRAND-NAME VIAGRA, MAKE SURE YOU GET THE BRAND NAME. Availability Prescription only How Sildenafil (Viagra) works Sildenafil (Viagra) is a phosphodiesterase-5 (PDE-5) inhibitor. PDE-5 is a protein in your body that breaks down the molecules that normally cause an erection.