What side effects can this medication cause? Therefore the use of such treatments in combination with Cialis is not recommended. Always keep medications out of reach of children and pets. Cialis can be taken daily, providing constant treatment for ED for people who have sex frequently. Cialis reaches its maximum effectiveness two hours after you take it. A deep dive into the ins and outs of purchasing this popular medication online, ensuring that you make informed decisions every step of the way.Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency in adult men. Dosage. The dose of Cialis you need will depend on whether you’re taking it daily or as needed. Daily doses are often between and 5 milligrams (mg). The as-needed dose is usually 10 mg but can range from 5–20 mg. The typicaldose of Viagra is 50 mg. However, the dosage can range from 25– mg. AdComplete the Online Consultation with our Doctor. Personalize Your Needs. If Appropriate, Get a Prescription for ED from RexMD®. Free Shipping AvailableFree Shipping · Real Doctors · Discreet Packaging · Personalized Plan/5 (3, reviews).