Cialis can be taken daily, providing constant treatment for ED for people who have sex frequently. It works best when taken one hour before sex. That means you can have erections whenever you want or need them. Your healthcare provider will discuss which dose is right for you. Pearlman says it can often take months to get an appointment with a healthcare provider who can prescribe the medications commonly used to treat ED. Cialis lasts longer.Before taking Viagra, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or . Cialis and Viagra have both been shown to be safe and effective for erectile dysfunction. The main differences are cost and timing. For occasional use, most people start with Viagra which also tends to be cheaper. Cialis lasts longer and can also be . Shop male enhancement products at Walgreens. Find male enhancement products coupons and weekly deals. Pickup & Same Day Delivery available on most store items. Buy 1, Get 1 50% OFF Buy 1, Get 1 50% OFF. Extra 15% off $30 Sitewid Not sold at your store. Check other stores Opens a simulated dialog.