Cialis is the trade name and generic name for tadalafil tablets, which generally does not thicken or enlarge the penis. Penile shortening is a condition in which the length and thickness of an adult man’s penis is less than the average for a normal man when it is weak and erect, and tadalafil tablets do not treat it. Tadalafil tablets are used to treat male erectile dysfunction, which is defined as the persistent inability of the penis to achieve or maintain an erection sufficient to accomplish a satisfactory sexual life for a period of more than three months; the main manifestation is often unable to have a normal erection, or the erection is not sufficiently hard to complete sexual intercourse, or the duration of erection is too short to complete sexual intercourse. It is important to note that this product should not be taken by patients with known hypersensitivity to tadalafil and its prescribed ingredients; it is contraindicated in women. The most common adverse reactions to tadalafil tablets are headache and indigestion, which are usually mild to moderate. This drug is a prescription medication.