Cialis (Tadalafil) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. These lists contain up to 10 of the most common mild side effects that can occur with Cialis, with Viagra, or with both drugs (when taken individually). This list contains examples of serious. Learn about the side effects of tadalafil, from common to rare, for consumers and healthcare professionals. Although rare, Cialis can cause serious side effects like sudden hearing loss or vision changes, chest pain, or a prolonged erection that requires immediate medical attention. The risk of. Learn about common and serious Tadalafil side effects from FDA labeling, how to manage them, and when to seek immediate medical attention. Cialis (tadalafil) may cause headaches, stomach upset, and back pain. It can also cause prolonged erections in some people. Review the side effects of Cialis and learn how to manage them. Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco. What are the serious side effects of tadalafil? While less common, the most serious side effects of tadalafil are described below, along with what to do if they happen. Tadalafil's most common side effects - headache, flushing, indigestion, back pain, and nasal congestion - are generally milder than those of sildenafil (Viagra) but longer-lasting, reflecting the drug's 36-hour duration of action. Learn about tadalafil side effects long-term, including daily Cialis use, heart safety, organ risks, and what happens if you stop—based on current medical evidence.