Cialis is a prescription treatment for erectile dysfunction (impotence), which contains an ingredient tadalafil. Tadalafil is known as a phosphodiesterase type 5 inhibitor, and stops a chemical in the body called phosphodiesterase type 5 from working.
You can buy cialis online in various dosages of 10 mg and 20 mg which should be taken depending on the condition of the man. Cialis effects can last for up to 36 hours after it has been ingested, compare this to Viagra which last for up to 4 hours.