In fact, according to Reuters, it was rejected by the FDA in for the second time in 10 years. Without physical action to the penis, such as that occurring during sexual intercourse, tadalafil will not work to cause an erection. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. If you are taking tadalafil for erectile dysfunction on a regular schedule, take the missed dose as soon as you remember it. The FDA has published warnings against over-the-counter OTC sexual enhancement products , citing hidden active ingredients that may be harmful. John’s wort. We’ll tell you how much below.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. Find patient medical information for Cialis oral on MD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. CIALIS for the Treatment of ED and Symptoms of BPH. ED and symptoms of BPH may happen in the same person and at the same time. Men who have both ED and symptoms of BPH may take CIALIS for the treatment of both conditions. CIALIS is not for women or children. CIALIS must be used only under a healthcare provider’s care. Who .