Yes, ED pills can cause side effects. Those with pre-existing conditions should always consult a healthcare provider before taking new medications or supplements. While each PDE5 inhibitor differs slightly, they’re very similar in treating erectile dysfunction. When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse. Erectile dysfunction medications require a prescription from a licensed provider. In some cases, online ED providers accept health insurance.Generic Cialis (tadalafil): Starting at $39/month; Generic Cialis Daily (tadalafil): Starting at $89/month; Branded Viagra: Starting at $70/dose; Branded Stendra: Starting at $59/dose; Branded Cialis Daily: $/month. Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include headache and indigestion. Tadalafil (Cialis) does interact with some medications. Reviewed by: Kristianne Hannemann, PharmD. Connie Zheng, PharmD. Last reviewed on April 11, savings_outlined. GoodRx . Disp Pack. Tablet. No data.. Dosage. mg. 5mg. 10mg. 20mg. No data.. Quantity. 5. 6. No data.. Read More About This Drug.