Highlights
- Cialis, sometimes known as the “weekend pill,” can remain effective for up to 36 hours.
- Individual differences in men’s bodies may mean shorter or longer periods of effective time.
- A free consultation with a physician at eDrugstore.com can help you decide if Cialis is right for you.
Michael DiLeo, MD, has over 30 years of experience in clinical and academic medicine. Through medical school, residency, and private practice, he has functioned as both a specialist and a primary care practitioner. He has twice served as chief of staff of a large regional hospital. He is a published author on women's health for McGraw-Hill. Now writing full time, he is passionate about medical accuracy on the internet. Contributing original content as well as vetting the information people rely upon for accuracy, he appreciates the importance of these roles as readers base decisions on the information provided by the media. Dr. DiLeo believes that while the internet is no substitute for established medical care, it is invaluable as a source of education.
Each man’s body is different, and this means that individual results for men taking Cialis may vary. However, Cialis and its generic version, tadalafil) have a much longer half-life than other erectile dysfunction medications. Read on to find out how Cialis produces hard, long-lasting erections.
What Is Cialis, and How Is It Different From Viagra?
You may have heard of Viagra but have questions about Cialis. Both Cialis and Viagra are often prescribed to men suffering from erectile dysfunction (ED).
Viagra and Cialis are both vasodilators. This means that they work to help you achieve and maintain an erection by increasing the flow of blood to your penis. The active ingredient in Cialis is tadalafil, which you can purchase in its generic form for a much lower price.
Your doctor will work with you to decide which medication is the best for you. We answer some of the most common questions about Cialis in this article, and offer some of the key differences below.
| Viagra | Cialis | |
|---|---|---|
| Active Ingredient | Sildenafil | Tadalafil |
| When to take it | 1 hour before sexual activity | If taken as needed: 30 minutes before sexual activity If taken daily: at approximately the same time every day |
| How long does it last | Usually 2-3 hours | Up to 36 hours |
The Half-Life of Cialis Determines How Long Cialis Lasts
The half-life of a drug is how long it takes for half the drug to leave the body. In the case of Cialis, for most men, the medication starts affecting the body a half hour to an hour after taking a dose, and the drug typically remains in the system for around 36 hours, on average.
This means that Cialis is a drug with a relatively long half-life, much longer than other drugs with a similar function. (Viagra, for example, has a half-life of four hours.) This makes Cialis and its generic counterpart tadalafil good choices for men who want longer effectiveness in their erectile dysfunction (ED) medication.
While the times listed above represent averages of how long Cialis lasts, there are several other factors that can affect how long Cialis and tadalafil remain in your system and how long it remains effective.
The average half-life for Cialis is seventeen and a half hours, indicating that it will last longer for some men and not as long for others.
Cialis is also available as Daily Cialis, a low-dose version that’s taken every day. This formulation is a good option for men who want to be ready anytime, such as those who have a particularly active sex life.
Why Does Cialis Last Longer for Some Men?
Cialis will last longer for some men and less for others. Here are some of the factors that determine the differences.
Kidney and Liver Function
Most drugs are broken down in the kidneys and liver. If your kidney or liver function is impaired, this will affect how long medications stay in your bloodstream.
Other Medications
If you take certain drugs, such as those that inhibit the function of your kidney and liver, Cialis will stay in your system longer because it’s not being broken down efficiently. Some antacids (such as cimetidine) and foods like grapefruit juice can increase the amount of many drugs in patients’ blood.
Physiology
Each person’s body and physiology are different, and each patient will have a different reaction to Cialis. Some users will see effects for a longer period of time, while others have bodies that break Cialis down faster so it’s effective for a shorter time.
The way your individual body works will affect the dosage of Cialis that you and your physician choose, whether you opt for 10 or 20 milligrams of Cialis as needed or take 2.5 milligrams daily.
While each man is different, you can plan to get the most from your dose of Cialis or tadalafil by working with your doctor and following some simple steps.
What Are the Risks and Side Effects of Cialis?
Because Cialis works as a vasodilator to open up your blood vessels, it may combine with other drugs you are taking, such as blood pressure medication or heart medication. In this case, the effects of both medications may last longer or be stronger.
While lasting longer may sound good, coming on stronger can be quite dangerous. Taking multiple vasodilators together can result in a dangerous drop in blood pressure and lead to fainting.
Common side effects of Cialis and tadalafil include:
- Headache
- Indigestion
- Back pain
- Muscle pain
- Flushing
- Stuffy nose
Cialis should never be combined with other drugs in its class, such as Viagra (sildenafil) or Levitra (vardenafil). Taken together, these drugs combine to cause low blood pressure and other side effects, like headaches, vision problems, and indigestion.
For more detailed information about Cialis/tadalafil, see FDA Patient Information.
When Cialis Lasts Too Long
The extended effectiveness of Cialis and tadalafil make them popular choices for some men. However, it’s important to note that one of the rare side effects of Cialis, as well as other ED drugs, is priapism, or an erection that lasts for more than four hours.
While this may sound appealing or even funny, it is actually a medical emergency that can require shunts or surgery, and it’s extremely painful. If this happens to you, you need to get to the nearest emergency department to avoid long-term or even permanent damage to your penis.
When blood stays in the spongy tissues of the penis for too long, the blood will begin to stagnate, causing serious problems in the penis itself. In severe cases, priapism has forced doctors to perform surgery to save healthy tissue and prevent serious complications, including gangrene.
Fortunately, this side effect and condition are rare. However, it is one of the elements that men must consider when considering their choices of ED medication.
Are You Ready to Try Cialis?
If you are ready to try Cialis or tadalafil, it’s important to speak with a reputable, licensed physician. At eDrugstore, we offer a free, discreet online consultation with a licensed U.S. physician, who will help you find the right medication for you. Take control of erectile dysfunction to ensure a healthy and fulfilling sex life!
Elizabeth Nichols is an experienced and flexible author with extensive experience in both popular media and academic publishing. She specializes in health, medical and travel writing.
