A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. These include a heart attack, stroke or a serious heart rhythm disorder in the past six months. Its effects often last for 4 to 5 hours. Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. These medicines all work well for ED. Common ones include: Flushing of the skin. 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.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 . The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles . Schedule a COVID test now Virtual Care Don’t want to leave the house? Connect with a licensed provider 7 days a week from the comfort of home. Explore Virtual Care Loading MinuteClinic can treat over different conditions. Find a walk in location near you today.