There are currently 3 oral impotence treatments available on the market Cialis, Levitra and Viagra.

Cialis, Levitra and Viagra have a slightly different chemical make up. These minor differences mean that the three treatments behave slightly differently.

The major difference in these three drugs is in the length of time the drug is effective and in how quickly the drug takes effect. The effects of both Levitra and Viagra can last for up to four hours. The effects of Cialis have been known to last for as long as 36 hours, which is why Cialis is often referred to in the world of erectile dysfunction as the “weekend pill“. Both Levitra and Viagra are said to begin working in about 30 minutes. Though there are some accounts that say that Levitra can begin to work quicker than Viagra and also that Levitra will work regardless of the foods eaten. Cialis is said to begin working within 15 to 30 minutes.

To sum up:

Viagra
Viagra has been available since April of 1998, patented and manufactured by Pfizer. Viagra was the First ED treatment to come onto the market.
Viagra should be taken an hour before sexual activity on an empty stomach.
In 30 – 60 minutes, a noticeable effect occurs which can last up to five hours.
The most commonly known side effects are headache, facial flushing, and can sometimes alter vision causing an excess of blue tint.
Despite the possible risks involved, Viagra has proven to be an effective treatment for ED, and its popularity has made it widely distributed with a reduced price for easier accessibility.

Cialis
The latest ED treatment has been Cialis, manufactured by Eli Lilly & Company since February 2003.
You make take Cialis approximately 30 minutes – 12 hours before sexual intercourse.
This medicine lasts longest in the body compared to Viagra and Levitra, possibly up to 36 hours to be exact. Therefore, sexual activity can be more spontaneous and there is no race against time.
The common side effects include headache, dyspepsia/upset stomach, and back pain.

Levitra
Manufactured by Bayer, Levitra has been available to the public since April 2003.
It comes in three different strengths (5 mg, 10 mg, and 20 mg).
Levitra is best taken 25 – 45 minutes before intercourse, and it is possible to take the medicine along with food without any restrictions
An effect can be felt in less than 20 minutes and lasts for six hours in the body.
The common side effects include headache, dyspepsia/upset stomach, facial flushing, and back pain.