Cialis can also interact with other medications, including nitrates and blood pressure medications. Common side effects include headache, facial flushing, indigestion, and dizziness. How long does Cialis last? In some cases, online ED providers accept health insurance. Read our editorial process. When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse. It’s best to check your chosen provider’s site for more information.Prices vary greatly depending on which medication you’re prescribed. Generic versions cost much. Yes. Cialis is approved by the FDA to treat erectile dysfunction (ED). Our medical team can prescribe Cialis 5mg, 10mg, and 20mg. The starting dose we generally recommend is 10mg. Tadalafil is the name for the active chemical ingredient in Cialis. PDE-5 inhibitors is the name of the group of medicines. Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash.