Manforce 50 mg can be taken with or without food, but consuming a heavy, high-fat meal may delay its onset of action. Limit alcohol intake, as excessive alcohol consumption can interfere with the effectiveness of the medication. Like any medication, Manforce 50 mg can have potential side effects. Common side effects may include headache, flushing, nasal congestion, upset stomach, and changes in vision. Serious side effects are rare but can include priapism (prolonged and painful erection) and sudden changes in vision or hearing.