Cialis (Tadalafil)

Take 1 tablet (5 mg) orally once a day with water, at approximately the same time each day, with or without food. Do not take more than one dose per day.

Cialis contains tadalafil, a PDE5 (phosphodiesterase type 5) inhibitor. During sexual arousal, nitric oxide is released in the penis, raising cGMP levels and relaxing smooth muscle so blood can flow in. PDE5 breaks cGMP down; tadalafil blocks PDE5, sustaining the increased blood flow that produces and maintains an erection. Tadalafil has the longest half-life of any PDE5 inhibitor (roughly 17.5 hours), which is why a low daily dose provides continuous readiness rather than requiring on-demand timing.

The most common side effects are headache, flushing, indigestion, nasal congestion, back pain, and muscle aches, and these are usually mild and transient. Rare but serious effects include priapism (an erection lasting more than 4 hours, which requires immediate medical attention), sudden vision loss, and sudden hearing loss.

Do not use tadalafil if you take nitrates in any form (e.g. nitroglycerin) or riociguat — the combination can cause a dangerous drop in blood pressure. Use caution with alpha-blockers and other antihypertensives. Not suitable for men advised against sexual activity for cardiovascular reasons, or with severe liver or kidney impairment. This medication is for men only.

Tadalafil is FDA-approved for the treatment of erectile dysfunction. Cialis received FDA approval in 2003, and generic tadalafil has been FDA-approved since 2018.