For starters, all three drugs are PDE-5 inhibitors so they help relax compromised or hardened penile arteries thus allowing more blood to flow into the penis and subsequently cause an erection. All three drugs also help keep high levels of cGMP within the penis. What’s cGMP? It means cyclic guanosine monophosphate and it is an incredible substance which is naturally produced by the penile tissue in response to sexual stimulation and which aids vascular muscle relaxation. When high levels of cGMP are present, the penile arteries become relaxed and a natural and stiff erection will occur.

Unfortunately, in most men suffering from E.D., the PDE-5 enzyme neutralizes any available cGMP and without cGMP an erection will become flaccid or will not occur at all. That’s where PDE-5 inhibitors such as Viagra, Cialis and Levitra come in. These drugs “inhibit” or block the unwanted PDE-5 and hence the very much wanted cGMP is allowed to remain within the penis after sexual stimulation occurs, thus aiding the erection process and keeping the penis erect. The question is, “Since all of these drugs have the same effect, why should I choose one over another?”

Let’s compare the three PDE-5 inhibitors side by side to determine their differences:

Manufacturers:
Viagra: Pfizer
Cialis: Eli Lilly and ICOS
Levitra: GlaxoSmithKline and Bayer

Generic Name:
Viagra: Sildenafil Citrate
Cialis: tadalafil
Levitra: vardenafil hydrochloride

Dosages: Available and Recommended:
Viagra: 25 mg, 50 mg, and 100 mg tablets. Most patients begin using the 50 mg pill and either increase or decrease the dosage based on drug tolerance and / or effectiveness. Most healthcare practitioners recommend taking Viagra 1 hour prior to sexual activity but studies have shown that Viagra can actually be taken anywhere from 30 minutes to 4 hours before having sex.

Cialis: 5 mg, 10 mg, and 20 mg tablets. It is recommended that you start out using 10 mg tablets and either increase or decrease the dosage depending on the results achieved. Traditionally, Cialis tablets can be taken anywhere from 30 minutes to 12 hours prior to sexual activity. Cialis soft tabs (which need not go through the digestion process) may be taken around 15 minutes prior to sexual activity.

Levitra: 2.5-mg, 5-mg, 10-mg, and 20-mg. Most people start out on the 10 mg pill and either work their way up or down depending on the results achieved. Levitra should be taken anywhere from 25 minutes to 1 hour prior to sexual activity, though some experts claim sex can be initiated in as early as 15 minutes.

How long does the effect last?
Viagra: approximately 4 hours
Cialis: approximately 17 to 36 hours (This is why they call Cialis the weekend pill.)
Levitra: approximately 5 hours

Year approved by the FDA:
Viagra: March 27, 1998
Cialis: November 1, 2003
Levitra: August 20, 2003

Cost of Pill

The cost for each of the 3 drugs is similar though Cialis tends to be a bit cheaper.

Success Rate

All three drugs work for approximately 70 percent of all men. Unfortunately, PDE-5 inhibitors won’t work for everyone. Certain men may need to use alternative treatments such as vacuum pump devices or even penile implants.

Side Effects

All three drugs share most of the same side effects. Some men may experience headaches, flushing, back pain, runny noses, stomach aches, or even changes in vision (example: some Viagra studies have revealed that on rare occasions a man may begin seeing a bluish tinge but that should go away after the drug has been eliminated from the body). These are all common side effects and should not be reason to worry excessively.

None of the three PDE-5 inhibitors should be taken in combination with low blood pressure medication as this can potentially cause a person to have a heart attack. People with high blood pressure should also take PDE-5 inhibitors only after consulting with their doctor. In fact you should never self-prescribe yourself with any of the 3 PDE-5 inhibitors or any other prescription drug for that matter. Even if you are purchasing your PDE-5 inhibitors online you must still open up and tell the pharmacist everything he/she needs to know in order to properly formulate the correct treatment for you.

What the drug looks like:
Viagra: Small blue tablet with the word Pfizer engraved in the middle.
Cialis: Yellow tablet that is almond shaped and film coated.
Levitra: Orange tablet with a flame logo.

Notable Differences

Basically the only major difference between the three drugs is that Levitra begins working the fastest and will work regardless of what kind of food you have previously eaten. Viagra has the proven track record and has been trusted by over 30 million men and Cialis is the longest lasting. In the end though, the real choice is up to you.

Even if I have severe ED, can Cialis® work for me?

Yes. Cialis® has been shown to work in men with all severities of ED. However individual results may vary. Your doctor is your best source of information for treatment options for erectile dysfunction.

If I have diabetes can Cialis® work for me?

Yes. Results from studies of men in the general population, including diabetics, and one study of only men with diabetes showed that 68% of men with diabetes mellitus reported improved erections.

How should I take Cialis®?

Cialis® comes in a 20 mg dose and can be taken with or without food. Beginning in 30 minutes and for up to 36 hours after taking the pill, Cialis® can help you get an erection if you are sexually stimulated. You results may vary. Do not take Cialis® more than once every 24 hours. Do not take Cialis® more often than your doctor recommends.