Vardenafil usually works for 4 to 5 hours. This medicine also works best when you take it an hour before sex on an empty stomach. It’s available in 10 mg and 20 mg tablets. Other uses for this medicine This medication may be prescribed for other uses; ask your doctor or pharmacist for more information. Its effects might last longer if you have mild to moderate ED. If you are taking tadalafil for erectile dysfunction on a regular schedule, take the missed dose as soon as you remember it.A manufacturer coupon or copay card is not available for Cialis. However, GoodRx discounts are available to help make it more affordable. Tadalafil, the generic version of . With SingleCare, Cialis costs as little as $ for 30, 20mg Tablet of generic Cialis, which could be more affordable than your insurance. Get our coupons for Cialis online or via . Use a mail-order pharmacy to get your medication. Using a mail-order pharmacy might help lower your cost for Cialis. Plus, you could get your medication without leaving home.