Cialis is a popular medicine which is also widely known under the generic name of Tadalafil. This medicine belongs to a class of muscle relaxant drugs. The drug is used for the effective treatment of impotency and erectile dysfunction.
Viagra is the brand name for sildenafil, a prescription drug used to treat erectile dysfunction (ED).
Sildenafil belongs to a class of medications called phosphodiesterase inhibitors, which work by increasing blood flow to the penis during sexual activity, resulting in an erection.