Cialis 20mg Tablets (4) are used to treat erectile dysfunction (ED) in men. The active ingredient, tadalafil, works by increasing blood flow to the penis, helping men achieve and maintain an erection when sexually stimulated. It can also be used to treat symptoms of benign prostatic hyperplasia (BPH). Cialis is known for its long-lasting effects, with results typically lasting up to 36 hours. Always follow the prescribed dosage and consult a healthcare provider for proper use and guidance.