Comparing Erectile Dysfunction Drugs

Tuesday 25 May 2021
Erectile Dysfunction
6 minute(s) read

Table of Contents

I. Understanding ED

II. Cialis

III. Viagra

IV. Levitra

V. So, what’s the consensus?

Understanding ED

Many men may require the use of erectile dysfunction (ED) medication throughout their life. In the United States, 1 in 5 men report a form of ED, and that number only increases as men age. Although it is common, ED is not a normal sign of aging. There are several physical and psychological causes of ED, and some men experience a combination of both. Risk factors for ED often include:

  • Being overweight
  • Undergoing prostate surgery or radiation treatment
  • Stress, anxiety, or depression
  • Drug and alcohol use
  • Tobacco use
  • Medical conditions like diabetes or heart conditions [1]

a diagram displaying how an erection occurs

ED occurs when a man cannot get or maintain an erection long enough to have sexual intercourse. This can be devastating to a man’s sex life, so it is vital to seek treatment from a primary care physician. An erection is caused by the engorgement of the penis with blood. Under normal conditions, sexual stimulation leads to the production and release of nitric oxide in the penis. Nitric oxide activates an enzyme that causes the production of cyclic guanosine monophosphate (cGMP). This enzyme is responsible for the amount of blood that the vessels deliver and remove from the penis.


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In some cases, ED can be an early sign of heart problems and vascular issues. If ED is left untreated, it can cause stress, fatigue, depression, and feelings of inadequacy. There are several drugs out there like Cialis, Viagra, and Levitra that can improve ED symptoms, but what’s the difference between these drugs? Read on to learn more about the different types of erectile dysfunction medications available. [2]


Cialis, also known as tadalafil, is a medication used in the treatment of erectile dysfunction. This drug works by blocking an enzyme called cGMP-specific phosphodiesterase type-5 (PDE-5). Tadalafil blocks PDE-5, which increases cGMP levels within the smooth muscles and promotes muscle relaxation and vasodilation.  In simpler terms, tadalafil widens blood vessels in certain regions of the body. There are high levels of PDE-5 found in the lungs, retina, and penis. Because of its function, Cialis is known as a PDE-5 inhibitor. The effects of Cialis only occur when a man is sexually aroused. [3]

Cialis can improve blood flow to the penis, but it also treats the signs and symptoms of benign prostatic hyperplasia (BPH). BPH is another common ailment men experience as they get older. BPH involves an enlarged prostate gland that may block the flow of urine out of the bladder. It can lead to bladder damage, kidney damage, bladder stones, and urinary tract infections. BPH has similar risk factors to ED, including smoking, diabetes, and being overweight. [1]

a cartoon of someone with a backache

Some people may prefer Cialis over other ED medications because it can be taken daily. Cialis is available at a lower strength, so it can be taken daily, which eliminates the need to “plan” for sex. The effect of Cialis can last for up to 36 hours.

Some possible side effects of Cialis can include:

  • Headache, back pain, nasal congestion, and flushing are the most common symptoms.
  • A possible drop in blood pressure, muscle or limb pain, or conjunctivitis may occur.
  • May cause hearing loss or lead to painful erections lasting longer than four to six hours.

It is important to note that dosages of Cialis vary depending on a man’s health condition. The dosage may need to be reduced if kidney or liver disease is present. Medications that include nitrates may interact with Cialis. [3]


Viagra, also known as sildenafil, is a commonly prescribed medication for erectile dysfunction. Viagra is a phosphodiesterase 5 (PDE-5) inhibitor, like Cialis. This medication is used for erectile dysfunction as well as a treatment used to slow the progression of pulmonary hypertension. Pulmonary hypertension is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart. PDE-5 inhibitors may even reverse some damage to the heart and lungs.

This drug works for ED because the body has the same type of blood vessels in the lungs as well as the penis. Like Cialis, PDE-5 inhibitors relax the blood vessels of the penis to assist in erectile dysfunction. [4]

a closeup of a blue eye

Some side effects of Viagra can include:

  • Nausea
  • Dizziness
  • Rash
  • Urinary tract infections
  • Facial flushing
  • Headaches
  • Possible vision changes and color perception
  • Priapism (an erection that lasts more than 4 hours)

Viagra does not stay in the system as long as Cialis. Viagra only lasts for about 4 to 6 hours. This is beneficial for some if a man only wants to take Viagra as needed for sexual intercourse. Sildenafil is rapidly absorbed, so it takes about an hour for the maximal concentration of this drug. When taking Viagra, it is crucial not to mix it with any other PDE-5 inhibitors like Cialis. Viagra also increases the effects of blood pressure-lowering medications. [5]


If a man is suffering from ED, then Levitra may be prescribed. This drug is also known as vardenafil. Like Viagra and Cialis, vardenafil is a phosphodiesterase type 5 inhibitor. As described above, PDE-5 drugs allow greater blood flow to the penis to sustain an erection. Levitra only works when a man becomes sexually stimulated and does not increase sexual desire. The recommended dose for Levitra depends on a man’s health condition. The usual recommended dose is one 10 mg tablet taken 25 to 60 minutes before sexual activity. [6]

Levitra is used when needed, and, like Viagra, it is advised not to take this medicine more than once a day. A man should allow 24 hours to pass between doses. It is important to pay attention to any side effects, including:

  • Painful erection that lasts longer than 4 hours
  • Heart attack symptoms (chest pain, nausea, sweating, pain in the jaw or shoulder)
  • Stuffy nose
  • Upset stomach
  • Back pain
  • Flushing

Like Viagra and Cialis, nitrate medications should be avoided to prevent dangerous drug interactions. In general, Levitra has fewer side effects than Viagra. Vision changes are considered a common side effect of Viagra, but changes to color perception are only a rare side effect of Levitra. [7]


a pile of multi-colored pills

So, what’s the consensus?

Every medication has its pros and cons. A doctor will help determine which drug is best for a man’s condition. A physician will consider a man’s age, weight, and pre-existing health issues to determine the most effective erectile dysfunction drug. No matter what a man decides, Canada Pharmacy Depot is the place to get erectile dysfunction medications at a discounted cost.

The content in this article is intended for informational purposes only. This website does not provide medical advice. In all circumstances, you should always seek the advice of your physician and/or other qualified health professionals(s) for drug, medical condition, or treatment advice. The content provided on this website is not a substitute for professional medical advice, diagnosis or treatment.


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