Common side effects include headache, facial flushing, indigestion, and dizziness. An erection results from an increase in blood flow to the penis. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. Insurance: If you plan to use insurance, make sure the online provider accepts it. However, all medications come with risks.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 is the brand name. There are many ways to save on Cialis, which is available as both a brand-name and generic medication. Save with GoodRx. GoodRx can help you save over 97% off the average retail price of the generic version. Generic Cialisat certain pharmacies is less than $13 with a free GoodRx discount. Tadalafil (Cialis) is taken by mouth either as needed before sexual activity or once daily for erectile dysfunction (ED). It’s also taken once daily to treat symptoms from an enlarged prostate (benign prostatic hyperplasia, or BPH). Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication.