Viagra, Cialis and Levitra all treat erectile dysfunction in the same way, but they differ in how fast they work, how long they last and how food affects them.
How they work
Sildenafil, tadalafil and vardenafil are all PDE5 inhibitors. They relax the blood vessels in the penis so more blood can flow in when you are sexually aroused. None of them causes an erection without arousal, and none of them increases sex drive.
Side-by-side
| Sildenafil (Viagra) | Tadalafil (Cialis) | Vardenafil (Levitra) | |
|---|---|---|---|
| Starts working | 30–60 minutes | About 30 minutes to 2 hours | About 60 minutes |
| Lasts | About 4 hours | Up to 36 hours | About 4–5 hours |
| Heavy, fatty meal | Can delay it | Little effect | Can delay it |
| US strengths | 25, 50, 100 mg | 2.5, 5, 10, 20 mg | 2.5, 5, 10, 20 mg |
| Daily option | No | Yes (2.5–5 mg) | No |
Which one is right for you?
- Tadalafil suits people who want more spontaneity: one dose can last a whole weekend, and the daily option means no planning at all. The 5 mg daily dose also treats urinary symptoms of an enlarged prostate.
- Sildenafil has been used the longest and is often the least expensive. It's taken only when needed.
- Vardenafil works in a similar way to sildenafil and is an alternative if one doesn't suit you.
Your prescriber will help you choose based on your health, your other medicines and how you'd like to take it.
Common side effects
All three can cause headache, flushing, a stuffy nose and indigestion. Tadalafil can also cause back pain and muscle aches. Sildenafil can cause a temporary blue tinge to vision.
Important safety rules
- Never combine any of them with nitrates (such as nitroglycerin) or riociguat.
- Don't take two ED medicines together, and don't take more than one dose a day.
- Get help right away for chest pain, an erection lasting more than 4 hours, or sudden vision or hearing loss.
We sell FDA-approved sildenafil, tadalafil and vardenafil, dispensed after our pharmacist verifies your prescription.