How Does Cialis Work and What to Do If It Doesn’t

Reviewed by Katelyn Hagerty, FNP

Written by Geoffrey Whittaker

Updated 26/04/2023

Cialis® is one of several medications used to treat erectile dysfunction (ED). But what if Cialis is not working for you? What do you do then?

It’s a question most people never have to ask. Like Viagra®, Stendra® and Levitra®, Cialis is highly effective as a treatment for ED. But unlike the competitors and thanks to its long half-life, Cialis can provide relief from erectile dysfunction that lasts for 36 hours. Basically, it thinks it’s a little bit better than everyone else.

Experts generally agree that it’s great, by the way. Studies of tadalafil, the active ingredient in Cialis (which is the brand name version), show that it improves erections and enhances sexual performance even at a relatively low dose. 

However, no medication has a 100 percent success rate, and Cialis is no exception. Even after you take Cialis, you could still experience some symptoms of ED. 

Below, we’ve explained how Cialis works, some reasons why it might not work for you and some things you can do if Cialis doesn’t treat your ED. 

How Does Cialis Work?

ED medications are all very similar, so it’s easy to paint with wide brush strokes when we talk about how ED meds work. Tadalafil, the active ingredient in Cialis, works the same way as the sildenafil used in Viagra, the avanafil used in Stendra or the vardenafil used in Levitra. 

These medications are all categorized as phosphodiesterase type 5 or PDE5 inhibitors, which help improve blood flow to the smooth muscles in your penis.

Tadalafil increases blood flow to the blood vessels in the erectile tissue of your penis by inhibiting the PDE5 enzyme that keeps those muscles rigid. This makes it easier for blood to move into your penis when you’re ready for sexual activity, giving you an erection.

How Long Does Cialis Take to Work?  

This medication kicks in pretty reliably as well. For most people, Cialis typically begins working within 30 minutes to one hour. 

Depending on the cialis dosage you’re prescribed (and how you’re instructed to take it) that may mean different things for your ability to get and maintain an erection. 

A daily dose works for you around-the-clock, helping you to have an erection anytime you get aroused. As-needed doses, on the other hand, might work for up to 36 hours, again depending on how you’ve been instructed to use it. 

If you’re concerned about making sure you’re primed for performance during game time and wondering when to take Cialis, it’s best to talk to a healthcare provider about any questions you may have. 

Factors That Can Affect How Cialis Works

As any guy who’s been catfished on a dating app knows, expectations don't always measure up to reality. When it comes to Cialis results, the same can be true — sometimes, things don’t work out the way we’d like. But what causes Cialis to deliver disappointing results? It can be a number of things, including:

  • The drug’s own efficacy

  • Using Cialis incorrectly

  • Using the wrong dose

  • Performance anxiety

  • ED caused by psychological issues

  • Porn addiction

Let’s look at these reasons Cialis can fail in more detail.

Cialis Efficacy Statistics

The first is just a numbers game. According to Harvard Men's Health Watch, the active ingredients used in Cialis, Viagra, Stendra and Levitra are only fully effective for healthy men around 70 percent of the time, meaning that many men still have erection issues even with the use of medication.

That means that three out of 10 boners just may not materialize the way you want them to. It’s certainly better than zero, but we get that you might be a little disappointed with “average” results.

You’re Not Using Cialis Correctly

Look, we don't like to read the instructions either,  but when it comes to medications like Cialis, it's extremely important to avoid winging it.

Cialis is designed to be used under specific conditions for maximum effectiveness. While you should always take Cialis exactly as your healthcare provider tells you to, it is generally recommended that for optimal results, you should:

  • Take Cialis at least one hour before sex. How long does it take Cialis to work? Cialis can take up to one hour to start fully working inside your body, according to an article published in the journal Patient Preference and Adherence. Try to take your Cialis tablet at least one hour before sex for optimal results. Since Cialis is a long-lasting medication, you can take it several hours before sex without having to worry about its effects wearing off.

  • Avoid drinking alcohol or taking recreational drugs. Not only can alcohol make Cialis and other medications less effective, but it can also affect your blood flow. This side effect of mixing Cialis with alcohol makes it harder to get an erection even with the help of medication.

You’re Not Using the Right Dose of Cialis

Cialis comes in several dosages: 2.5 mg, 5 mg, 10 mg and 20 mg. Most of the time, the 10 mg and 20 mg dosages are used as-needed for the treatment of erectile dysfunction.

Lower doses of Cialis, like 2.5 mg and 5 mg tablets, tend to be used as daily doses to treat mild ED and medical conditions such as benign prostatic hyperplasia (BPH), according to a clinical trial published in The Journal of Sexual Medicine

If you’re prescribed a lower dosage of Cialis and you find that it’s not fully effective (for example, you notice some improvements but still have difficulty maintaining an erection), it’s a good idea to discuss this with your healthcare provider to see if switching you to a higher dose is appropriate.

You’re Experiencing Performance Anxiety

ED can be caused by sexual performance anxiety — a feeling of nervousness and anxiety before and during sex. If you’re affected by sexual performance anxiety, it’s quite normal to feel worried about Cialis’ effectiveness the first few times you use it.

This nervousness can result in worse ED than normal even after sexual stimulation, meaning that Cialis might not be totally effective as a treatment. 

If you find that Cialis doesn’t work the first time you use it at a normal dosage, stick with it before you throw in the towel on this specific medication. Wait until you feel relaxed, confident and in the right mood so that you can judge Cialis’s performance fairly. 

If problems persist, let your healthcare provider know and see what they have to say. They may recommend a different dose, or even switch you to another ED medication altogether.

Your ED is Caused by a Psychological Condition

Cialis is designed to treat erectile dysfunction’s physical causes, such as poor blood flow to the erectile tissue of your penis. However, it’s not a psychiatric medication and isn’t designed to be a treatment for psychological causes of ED.

According to an article published in the journal Health Psychology Open, erectile dysfunction can be associated with anxiety, stress and depression. If you have a mental illness or other condition that affects your sexual performance, the use of Cialis and other ED drugs might not be completely effective. 

If you think one of these conditions is the cause of your ED, your healthcare provider may suggest therapy, anxiety and depression medications, as well as other treatment options. 

Get hard, stay hard

Get effective, affordable ED treatment... from your home!

Your ED is Caused by a Physical Health Condition

Erectile dysfunction is often caused by a physical health condition, such as: 

Tadalafil, the active ingredient in Cialis, works by increasing blood flow to the erectile tissue of your penis. But if your ED is caused by another physical condition that doesn’t affect blood flow or causes decreased blood flow, it may not be completely treated by Cialis.

According to an article published in the Arab Journal of Urology issues like low testosterone can also affect both your sexual performance and your general level of interest in sex. Because Cialis isn’t a hormonal medication, it might not be completely effective at treating ED caused by low testosterone. 

Porn is Affecting Your Sexual Performance

If you frequently watch porn, it could negatively affect your sexual performance. Porn-induced ED affects your sexual tastes, expectations and perceptions. 

Porn consumption can also potentially result in anxiety around sex, which can contribute to erectile dysfunction.

Since this is a psychological cause of ED, it often can’t be fully treated with medications like Cialis, Viagra, Stendra or Levitra. Our guide to porn-induced ED explains this phenomenon in more detail and shares techniques that you can use to avoid letting porn affect your sex life. 

ED treatments, delivered

No matter the treatment plan, the best place to start is somewhere.

Prescription

Hard Mints by Hims

Tadalafil + Sildenafil

From £3/use

  • A fresh new way to treat ED. Chewable mints in a discreet portable tin

  • The same active ingredients as Cialis® and Viagra®

  • Ingredients shown to help men get harder erections and last longer

  • Tadalafil works in as little as 60 minutes and can last up to 36 hours

Prescription

Traditional Pill

Generic Viagra®Sildenafil

From £2.25/use

  • Uses the same exact active ingredient as brand name Viagra® (no chemical difference)

  • 80% cheaper than the brand name

  • The most commonly prescribed ED treatment

Prescription

Hard Mints by Hims

Tadalafil Daily

From £33/month

  • Chewable once-daily mints in a discreet portable tin

  • Formulated with the exact same active ingredient as Cialis®

  • Active ingredient that builds up in the body if you want to be ready 24/7 and don't want to plan ahead

Prescription

Traditional Pill

Daily Generic Cialis®Tadalafil Daily

From £24/month

  • Daily ED pill formulated with the exact same active ingredient as Cialis®

  • Active ingredient that builds up in the body if you want to be ready 24/7 and don’t want to plan ahead

Prescription

Traditional Pill

Generic Cialis®Tadalafil

From £2.25/use

  • The unbranded, more affordable generic form of Cialis® taken as-needed

  • As-needed tadalafil lasts for 24-36 hours

  • Helps get and keep harder erections

Over-the-counter

Traditional Pill

Viagra Connect®

From £5.83/use

  • The classic over the counter Blue Pill

  • Used by men who know they want the brand name pill

  • The original ED drug

Important safety information for Sildenafil, Tadalafil, Tadalafil Daily or Viagra Connect.

Common Side Effects of Cialis to Keep in Mind

According to the FDA, common side effects of Cialis include:

  • Headache

  • Indigestion

  • Back pain

  • Muscle pain

  • Flushing of the skin

  • Stuffy nose 

More serious side effects include:

  • Chest pain

  • Heart attack

  • Low blood pressure

  • Allergic reaction

  • Prolonged erection (also known as priapism)

Additionally, you’ll want to talk to your healthcare about the potential for drug interactions if you’re taking other medications. Among other medications, Cialis may interact in dangerous ways with any of the following:

  • Alpha-blockers

  • Nitrates like nitroglycerin and amyl nitrate

  • “Poppers” and other nitrites 

  • Antifungal medications like itraconazole and ketoconazole

  • Riociguat, a drug used to treat pulmonary hypertension

Get hard, stay hard

Get effective, affordable ED treatment... from your home!

How Cialis Works: Final Thoughts

Cialis works when you use it correctly most of the time. But when you start messing with the system, those changes and deviations can keep your rocket from achieving liftoff. 

And that’s just one version of user error that may cause tadalafil to fail you. If you’re taking Cialis, and not getting the results you want, remember some key points:

  • Dealing with erectile dysfunction can be a frustrating experience, especially if you don’t get the results you anticipated from medications like Cialis. 

  • These medications are real, proven, science-backed erectile dysfunction treatments though, and are generally effective when used correctly.

  • Using them incorrectly — having the wrong dosage or not following instructions — can cause Cialis not to work.

  • Cialis might also fail if your ED is related to psychological issues — performance anxiety, intimacy issues, low self-confidence and depression can all affect your erections.

  • FDA-approved prescription medications like Cialis are substantially more safe and effective than supplements and over-the-counter treatments you might get elsewhere.

So if Cialis is failing you, talk to a healthcare provider today about other options. They may adjust your dose, give you some tips or switch you to another medication. Whatever it takes, get your ED under control today, buddy — you deserve to enjoy sex.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

ED treatment that comes to you

Answer some questions

Consult with a licensed provider

Get ED pills delivered, if prescribed

Get started