Viagra use recommendations from Doktererectie! Read on Cialis usage, inform yourself, get the best benefits and stay safe. Common side effects of Viagra include dizziness, headache, flushing, upset stomach or indigestion, abnormal vision (such as increased sensitivity to light, blurred vision, or blue-tinted vision), nasal congestion or runny nose, back pain, insomnia, rash, and muscle […]