Megalis 20 mg is generally taken as needed, usually before sexual activity, according to a healthcare provider’s instructions. It may start working within 30–60 minutes, and its effects can last for up to 36 hours in some men. The medicine does not increase sexual desire and does not cause an erection without sexual stimulation. Common side effects may include headache, facial flushing, nasal congestion, indigestion, dizziness, back pain, and muscle aches. These effects are usually mild, but medical advice should be sought if they are severe or persistent. https://www.genericday.com/megalis-20-mg.html