Cialis Information from Eli Lilly and Company
Provides information about Cialis on the drug manufacturer’s official website.
Cialis Information from the FDA
Information from the Center for Drug Evaluation and Research under the US Food and Drug Administration.
MedlinePlus Drug Information: Tadalafil (marketed as Cialis)
Information about Cialis from the US National Library of Medicine and the National Institutes of Health
Information about erectile dysfunction from the National Institute of Diabetes and Digestive and Kidney Diseases or NIDDK, and National Institutes of Health