Megalis 20 mg contains the active ingredient Tadalafil, which is used to treat erectile dysfunction (ED). Tadalafil belongs to a class of medications called phosphodiesterase type 5 (PDE5) inhibitors. It works by increasing blood flow to the penis, allowing for an erection to occur during sexual stimulation. When it comes to the compatibility of Megalis 20 mg with alcohol, it's essential to consider potential interactions and side effects. Alcohol consumption can potentially worsen certain side effects of Tadalafil, such as dizziness, headache, and changes in blood pressure.