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Cialis® (Tadalafil) Side Effects: What to Expect

Mike Bohl, MD, MPH, ALM

Reviewed by Mike Bohl, MD, MPH, ALM

Written by Nick Gibson

Published 07/01/2019

Updated 12/11/2023

If you've just started taking Cialis®, you might be hypersensitive to some of what you're feeling. Is that hair in the bottom of your sink normal, or is it a side effect? 

What about your feet — they're smelling a little funky today. Is that a side effect, or do you just need to do a better job getting in between your toes next time you shower?

Like other medications for the treatment of erectile dysfunction, Cialis — and its generic version, tadalafil — can cause adverse effects. 

Most side effects of Cialis are mild and resolve on their own over time. However, there are a few side effects that you should be aware of before starting treatment, as well as drug interactions that could occur when Cialis is used with other medications. 

Below, we’ve explained:

  • What you can expect when using this treatment for ED (besides better erections) 

  • Common and uncommon side effects of Cialis

  • Side effects that may come from taking Cialis with other medications 

Here’s a look at Cialis’ less-fun side. 

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Cialis has several common side effects, many of which also occur with other drugs used to treat erectile dysfunction like sildenafil (generic Viagra), vardenafil (Levitra®) or avanafil (Stendra®). One difference is that Cialis is active in the body for longer than other oral ED medications, which means its side effects can stick around for longer, too. These side effects include:

  • Headaches

  • Heartburn/Indigestion

  • Back pain

  • Muscle aches

  • Facial flushing

  • Nasal congestion

  • Nasopharyngitis (common cold symptoms)

  • Pain in limbs

Headaches

Headaches are a common side effect of oral ED medications, and Cialis is no exception. The things we do for love, eh?

 In fact, headaches are among the most frequently reported adverse effects of tadalafil, making an appearance in all clinical trials of this medication. 

According to a 2008 review of studies on tadalafil, 15 percent of men who use this medication at its highest recommended dose (20mg) experience headaches.

Headaches can still be common for those who take a lower 10mg dose of Cialis, affecting about 12 percent of men.

Most of the time, Cialis-induced headaches are mild and become less intense over time, although Cialis’ long half-life means that a dull headache might continue for several hours after the fun is over.

If you’re prone to headaches after taking Cialis, our guide to treating headaches from ED drugs may help. It discusses several practical techniques for managing this side effect, from adjusting your dosage to using over-the-counter pain relief medication.

Heartburn and/or Indigestion

If you've ever taken Cialis and felt butterflies in your stomach before clothes came off, it may not have been love. In fact, there’s a pretty good chance it was just a li’l indigestion.

Indigestion is the second-most common side effect of tadalafil, affecting about eight percent of users at 10mg dosage and 10 percent of users at a higher 20mg dose. 

Indigestion is a common side effect of oral ED medications, which are known as phosphodiesterase 5 inhibitors (PDE5 inhibitors for short).

Cialis causes your lower esophageal sphincter (the part of your body that normally stops stomach contents from going back up the esophagus) to relax. This may lead to heartburn as stomach acid travels from your stomach upward into your esophagus because, well, those are some other smooth muscle tissues in your body.

If you develop acid reflux, an upset stomach or other digestive issues after taking Cialis, making small changes — like drinking more water or using a generic antacid medication — can make this side effect easier to deal with. 

If you experience this side effect often, discuss your Cialis dosage with your healthcare provider. They may adjust your dosage or suggest other changes you can make to make Cialis a more fruitful experience.

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Back Pain

No, you're not just getting too old for this — Cialis can cause back pain, too. Roughly three to six percent of men who take it develop back pain, and the discomfort tends to occur around 12 to 24 hours after taking the medication.

What’s the back pain Cialis solution? Well, many people report that it usually fades on its own within 48 hours. In the meantime, you might consider treating mild to moderate back pain from Cialis with over-the-counter pain relief.

Muscle Aches

Like Viagra and other ED medications, a small percentage of men who use Cialis experience myalgia, or pain that involves your muscles, ligaments, tendons and/or fascia (connective tissues).

In clinical trials of Cialis, approximately one to four percent of men reported muscle pain as an adverse effect, with this side effect more common in men prescribed tadalafil at higher dosages.

Here's some good news: muscle aches from Cialis or other ED medications are typically mild and tend to only last while the medication is active in your body.

Facial Flushing

Feeling your cheeks getting red after taking Cialis? It may not just be those two glasses you had at date night dinner. 

Tadalafil is a vasodilator, which means it improves blood flow throughout your body, including to the erectile tissue of your penis. But this medication is also used to treat benign prostatic hyperplasia, or BPH, and (under the brand name Adcirca®) pulmonary arterial hypertension (PAH), a form of high blood pressure that can affect the arteries in the lungs.

Because Cialis causes your blood vessels to dilate, facial flushing is also on the table, including around your nose, cheeks, chin and forehead. This side effect can also occur elsewhere on your face and body. 

Around three percent of men who use Cialis experience facial flushing. This side effect typically occurs with moderate and high doses. Like with other side effects of Cialis, it usually fades as your body metabolizes the medication over the course of several hours.

Since facial flushing is a common oral ED medication side effect, switching to another drug might not help the issue. 

Nasal Congestion

When you use tadalafil, it may affect nitric oxide levels inside your nasal cavity, giving you a stuffy nose that could make it difficult to smell the love in the air.

As with many other Cialis side effects, nasal congestion tends to fade on its own as your body processes the medication.

While a stuffy nose is a common side effect of oral ED medications, switching from Cialis to shorter-lasting options like Viagra or Levitra might make sense, as these medications remain active in your body for shorter periods of time and may make this side effect (drum roll please) shorter.

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Nasopharyngitis (Common Cold Symptoms)

Some men who use Cialis to treat ED report developing cold-like symptoms, or nasopharyngitis, after taking the medication.

The common cold is caused by a viral infection — not Cialis. But because this medication affects the soft tissue inside your nose and throat, some users experience some suspiciously similar symptoms. 

But rest easy — you're not sick. Not from Cialis, at least.

Pain in Limbs

Limb pain is a real-deal side effect. In clinical trials, one to three percent of men who used Cialis reported experiencing leg pain and, on occasion, pain in their other limbs as well. This side effect was most common in men who were prescribed Cialis at a dosage of 10 or 20mg per day. 

Long-term Side Effects

There are no known long-term side effects associated with the use of tadalafil — in fact, studies have shown that over the long term (and if you can handle the shorter-term side effects), this medication is well tolerated.

However, quick reminder, fellas: even though it hasn’t been associated with long-term issues, that doesn’t mean you shouldn’t be careful to use only the prescribed amount, especially if you’re using Cialis daily.

Cialis has an impressively long half-life, which means one dose can last up to 36 hours (hence why it’s sometimes called “the weekend pill”). But you can also take Cialis daily at a lower dose if you’re the kinda guy who needs more assurance than for 36 hours at a time. 

In general, the common effects of Cialis taken daily are similar to those of Cialis when it’s taken as needed before sex. 

However, because daily-use Cialis is prescribed at a lower dosage, some side effects appear less common and are generally less severe.

For example, in clinical trials, 11 to 15 percent of men reported headaches from Cialis at a dose of 5mg to 20mg. In comparison, only three to six percent of men who took Cialis every day at a dose of either 2.5mg or 5mg reported headaches.

Other side effects, such as dyspepsia and back pain, were also reported less frequently by men prescribed Cialis for daily use. 

Our guide to daily Cialis provides more information about the advantages and disadvantages of using Cialis every day to treat ED.

Here's where things get a little more serious. While most of the side effects mentioned above are relatively benign (that's doctor-talk for "pretty mild"), the side effects below — although rare — require immediate care. 

So pay attention.

Serious adverse effects of Cialis include:

  • Priapism (a painful erection that may last for four hours or longer)

  • Optic nerve damage

  • Loss of hearing

  • Interactions with other prescription medications.

Priapism

Priapism is a prolonged, often painful erection lasting four hours or longer. While it might sound awesome in theory, in practice ischemic priapism is a medical emergency that requires immediate attention to avoid damaging the erectile tissue.

Although it’s possible to experience a prolonged erection after using Cialis, this is an extremely uncommon side effect. 

If you get a persistent and/or painful erection after using Cialis, it’s important to seek emergency medical care immediately. 

Optic Nerve Damage

Although exact data isn’t available, tadalafil was listed as one of several PDE5 inhibitors linked to rare reports of NAION in a study of sildenafil (Viagra) and optic nerve damage.

This condition is called non-arteritic anterior ischemic optic neuropathy, or NAION. It can develop when the blood supply to the optic nerve is reduced, potentially producing a reduction of the visual field.

Optic nerve damage may cause or contribute to vision loss (including retinitis pigmentosa). Like priapism, this is an extremely rare side effect that only affects a tiny percentage of Cialis users.

It’s also worth noting that NAION appears to occur primarily in people with a pre-existing risk factor for eye damage, such as a small cup-to-disc ratio.

Hearing Issues

Cialis has been linked to decreased hearing sensitivity or hearing loss in postmarketing reports.

Cases of sudden hearing loss caused by Cialis are very uncommon and evidence suggests that some of the reported cases of hearing loss associated with Cialis may be linked to underlying medical conditions.

And that, fellas, is why we tell our healthcare providers every single thing. 

If you take Cialis to treat ED and notice any changes in your hearing, it’s best to stop taking this medication and consult your healthcare provider immediately. 

Allergic Reaction to Cialis

It’s possible to have an allergic reaction to the tadalafil that’s used in this medication or to other, inactive ingredients that are used as part of the manufacturing process.

Common symptoms of an allergic reaction include hives; rash; swelling that affects the lips, throat and tongue; and difficulty breathing or swallowing.

If you experience any of the above symptoms or other possible signs of an allergic reaction after taking Cialis, it's important to seek emergency medical help.

Other Rare Side Effects

Other uncommon side effects of Cialis include chest pain, ringing that affects your ears and skin issues.

Make sure to inform your healthcare provider if you develop these or other side effects after you use Cialis or other medications for ED.

As a PDE5 inhibitor, Cialis can interact with other medications, including medications prescribed to treat hypertension (high blood pressure), fungal infections, cardiovascular health issues such as coronary artery disease (CAD) and heart failure, as well as other medical conditions.

Interaction With Blood Pressure Medications

Tadalafil can interact with nitrates used to treat hypertension, angina and other heart problems, which can cause abnormally low blood pressure that may lead to loss of consciousness, heart attack and even cardiac arrest (sudden death). Yikes. 

If you take nitrates like nitroglycerin, isosorbide dinitrate or isosorbide mononitrate to treat hypertension (high blood pressure) or angina (heart-related chest pain), you should not take Cialis because of this. 

In addition to nitrates used to treat cardiovascular conditions, ED medications can also interact with certain recreational drugs that contain nitrates, such as amyl nitrate “poppers.”

We know, we know… It’s a bummer. But it’s always better to be safe than sorry.

Interaction With Antifungal Medications

Cialis can interact with some oral antifungal medications like itraconazole or ketoconazole used to treat issues such as ringworm and fungal nail infections. These medications, which inhibit the CYP3A4 enzyme, may increase your exposure to the effects of Cialis.

Some other medications that affect CYP3A4, such as the antibiotic erythromycin, and ingredients that affect CYP3A4, such as grapefruit or grapefruit juice, may also interact with Cialis.

So, not-so-fun fact: If you want to take Cialis at night, you may have to stop eating grapefruit in the morning. 

You can read more about the relationship between grapefruit products and Cialis in our guide to Cialis and grapefruit interactions.

If you're prescribed these medications, your healthcare professional may adjust your dosage of Cialis to reduce your risk of developing side effects. 

The FDA suggests taking Cialis at a maximum as-needed dosage of 10mg no more than once per 72 hours — or a daily dosage of 2.5mg — if you’re prescribed any other medication that inhibits CYP3A4.

Other Medications That May Interact With Cialis

Other medications may also interact with Cialis, including the following:

  • Ritonavir. This antiretroviral medication inhibits CYP3A4 and may increase the effects of Cialis in your body.

  • Alpha-blockers. Alpha-blockers can cause a drop in blood pressure when taken with Cialis. These medications are frequently prescribed to manage high blood pressure, benign prostatic hyperplasia (enlarged prostate) and other conditions.
    Common alpha-blockers include Flomax® (tamsulosin HCl), Hytrin® (terazosin HCl), Cardura® (doxazosin mesylate), Uroxatral® (alfuzosin HCl), Jalyn® (dutasteride and tamsulosin HCl), Minipress® (prazosin HCl) and Rapaflo® (silodosin).

  • Other PDE5 inhibitors. Other PDE5 inhibitors, such as sildenafil (Viagra), vardenafil (Levitra) and avanafil (Stendra) will interact with Cialis.

Are side effects avoidable when you take prescription medications? Sometimes — if you follow the rules. And there are some important rules to follow when it comes to penis pills, including:

  • Make sure you get them from a reputable source.

  • Don’t take street or gas station supplements (read here for a list of reasons why)

  • Inform a healthcare provider of other medications and supplements you’re taking.

  • Take only the prescribed dosage.

Getting the right pills is important. Cialis comes in tablet form, making it convenient to use as a treatment for ED. Although some online vendors advertise liquid versions of Cialis, these products are unregulated in the United States. 

Dosage is also crucial to your safety. If you're prescribed Cialis for use “as needed,” most men find that a normal dose of Cialis starts working within 30 to 60 minutes and, as we mentioned above, can last for up to about 36 hours — significantly longer than other oral ED medications, such as Viagra (sildenafil), Levitra (vardenafil) or Stendra (avanafil).

Although there’s no simple, one-size-fits-all way to completely eliminate side effects from Cialis, there are several other things that you can do to reduce your side effect risk.

Limit Your Alcohol Consumption

As much as you may love those two glasses of wine on date night (and the nightcap before hitting the hay) try to limit your alcohol consumption while taking Cialis. 

Drinking alcohol with Cialis can increase your risk of experiencing side effects. Also, whiskey dick is a punishment we wouldn't wish on our worst enemy.

The best way to do this is to avoid any alcohol consumption. However, if you typically drink alcohol while out on dates or just as part of your normal lifestyle, limiting your consumption to one to two small servings can also help. 

Only Use Cialis as Prescribed

Medical advice is important to listen to. Most potential side effects of Cialis are dose-dependent, meaning they become more common at higher doses. Make sure to only use the dosage of Cialis prescribed to you. 

If you find it hard to get or maintain an erection after using Cialis, don’t adjust your dosage on your own. Instead, let your healthcare provider know about your concerns. 

Don’t Take Cialis More Than Once Per Day

Cialis is a long-lasting ED medication that’s not intended for use more than one time per day. A single dose of Cialis should produce a noticeable improvement in your erections that continues for up to 36 hours.

If you don’t notice any improvements after taking Cialis, do not take a second tablet. Instead, figure out a way to call a rain delay and let your healthcare provider know. They may suggest adjusting your dosage or switching to another ED medication. 

Avoid Grapefruit

This one seems out of place unless you’re familiar with grapefruit’s reputation as a blood pressure bad boy. Grapefruit juice can increase the serum concentrations of tadalafil and other medications in your body, which can lead to overdose-like results. Stick with water — it’s good for you.

Although Cialis is widely known as a treatment for erectile dysfunction, it's also approved by the FDA for use as a treatment for benign prostatic hyperplasia (BPH, or enlarged prostate).

Enlarged prostate is common in older men and typically carries symptoms of lower urinary tract problems which can become bladder problems over time.

As a treatment for BPH, tadalafil is typically taken daily. The potential side effects and interactions of Cialis are the same whether Cialis is used for ED or BPH, making it important to be aware of these effects before using this medication.

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It’s quite normal to experience one or several minor side effects from Cialis. However, serious side effects are pretty uncommon, luckily. 

That said, it’s important that a medication like this improves your quality of life — and doesn’t reduce it. After all, the point here is to have a great time getting laid, not to spend a bunch of time reading health information on the internet.

Let’s make this one of the last deep dives you have to do to understand your risks. Here’s what to remember if you’ve started taking Cialis or are about to take your first dose:

  • Don’t ignore side effects. If you’re prescribed Cialis for erectile dysfunction or benign prostatic hyperplasia and notice a concerning or problematic side effect, it’s important to talk to your healthcare provider as soon as possible.

  • Your dosage can change to fix problems. They may recommend adjusting your Cialis dosage or making certain changes to the way you take this medication. 

  • Other ED drugs can work if Cialis doesn’t. In some cases, your provider may recommend switching to another ED drug, such as sildenafil (the active ingredient in Viagra), vardenafil (Levitra) or avanafil (Stendra). These medications are shorter-acting than Cialis, meaning any side effects you experience may fade away in a shorter amount of time. 

Side effects aren’t something you’re stuck with. We offer several FDA-approved ED medications online, following a consultation with a licensed healthcare provider who will determine if a prescription is appropriate.

You can learn more about the causes of and treatments for ED in our complete guide to erectile dysfunction.

Don’t accept “acceptable” — get the right medication for you.

11 Sources

  1. Dhaliwal, A. & Gupta, M. (2022, May 20). PDE5 Inhibitors. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK549843/
  2. Tadalafil. (2022, February 15). Retrieved from https://medlineplus.gov/druginfo/meds/a604008.html
  3. Coward, R.M. & Carson, C.C. (2008, December). Tadalafil in the treatment of erectile dysfunction. Therapeutics and Clinical Risk Management. 4 (6), 1315-1330. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2643112/
  4. CIALIS- tadalafil tablet, film coated. (2017, May). Retrieved from https://www.accessdata.fda.gov/spl/data/05dbd8b6-1b9d-436a-a67c-8a16713f753f/05dbd8b6-1b9d-436a-a67c-8a16713f753f.xml
  5. Bortolotti, M., et al. (2001, November). Effects of sildenafil on esophageal motility of normal subjects. Digestive Diseases and Sciences. 46 (11), 2301-2306. Retrieved from https://pubmed.ncbi.nlm.nih.gov/11713926/
  6. Questions and Answers for Cialis (tadalafil). (2015, August 13). Retrieved from https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/questions-and-answers-cialis-tadalafil
  7. Stockman, A., et al. (2007, June). The effect of sildenafil citrate (Viagra) on visual sensitivity. Journal of Vision. 7 (8), 4. Retrieved from https://pubmed.ncbi.nlm.nih.gov/17685811/
  8. Too much of a good thing: The 4-hour erection. (2008, September 11). Retrieved from https://www.nbcnews.com/healthmain/too-much-good-thing-4-hour-erection-1C9926694
  9. Gorkin, L., Hvidsten, K., Sobel, R.E. & Siegel, R. (2006, April). Sildenafil citrate use and the incidence of nonarteritic anterior ischemic optic neuropathy. International Journal of Clinical Practice. 60 (4), 500-503. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448698/
  10. Washington, S. L., 3rd, & Shindel, A. W. (2010). A once-daily dose of tadalafil for erectile dysfunction: compliance and efficacy. Drug design, development and therapy, 4, 159–171. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2939761/.
  11. Ng M, Baradhi KM. Benign Prostatic Hyperplasia. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558920/
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

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. Learn more about our editorial standards here.

Mike Bohl, MD, MPH, ALM

Dr. Mike Bohl is a licensed physician, a Medical Advisor at Hims & Hers, and the Director of Scientific & Medical Content at a stealth biotech startup, where he is involved in pharmaceutical drug development. Prior to joining Hims & Hers, Dr. Bohl spent several years working in digital health, focusing on patient education. He has also worked in medical journalism for The Dr. Oz Show (receiving recognition for contributions from the National Academy of Television Arts and Sciences when the show won Outstanding Informative Talk Show at the 2016–2017 Daytime Emmy® Awards) and at Sharecare. He is a Medical Expert Board Member at Eat This, Not That! and a Board Member at International Veterinary Outreach.

Dr. Bohl obtained his Bachelor of Arts and Doctor of Medicine from Brown University, his Master of Public Health from Columbia University, and his Master of Liberal Arts in Extension Studies—Journalism from Harvard University. He is currently pursuing a Master of Business Administration and Master of Science in Healthcare Leadership at Cornell University. Dr. Bohl trained in internal medicine with a focus on community health at NYU Langone Health.

Dr. Bohl is Certified in Public Health by the National Board of Public Health Examiners, Medical Writer Certified by the American Medical Writers Association, a certified Editor in the Life Sciences by the Board of Editors in the Life Sciences, a Certified Personal Trainer and Certified Nutrition Coach by the National Academy of Sports Medicine, and a Board Certified Medical Affairs Specialist by the Accreditation Council for Medical Affairs. He has graduate certificates in Digital Storytelling and Marketing Management & Digital Strategy from Harvard Extension School and certificates in Business Law and Corporate Governance from Cornell Law School.

In addition to his written work, Dr. Bohl has experience creating medical segments for radio and producing patient education videos. He has also spent time conducting orthopedic and biomaterial research at Case Western Reserve University and University Hospitals of Cleveland and practicing clinically as a general practitioner on international medical aid projects with Medical Ministry International.

Dr. Bohl lives in Manhattan and enjoys biking, resistance training, sailing, scuba diving, skiing, tennis, and traveling. You can find Dr. Bohl on LinkedIn for more information.

Publications

  • Younesi, M., Knapik, D. M., Cumsky, J., Donmez, B. O., He, P., Islam, A., Learn, G., McClellan, P., Bohl, M., Gillespie, R. J., & Akkus, O. (2017). Effects of PDGF-BB delivery from heparinized collagen sutures on the healing of lacerated chicken flexor tendon in vivo. Acta biomaterialia, 63, 200–209. https://www.sciencedirect.com/science/article/abs/pii/S1742706117305652?via%3Dihub

  • Gebhart, J. J., Weinberg, D. S., Bohl, M. S., & Liu, R. W. (2016). Relationship between pelvic incidence and osteoarthritis of the hip. Bone & joint research, 5(2), 66–72. https://boneandjoint.org.uk/Article/10.1302/2046-3758.52.2000552

  • Gebhart, J. J., Bohl, M. S., Weinberg, D. S., Cooperman, D. R., & Liu, R. W. (2015). Pelvic Incidence and Acetabular Version in Slipped Capital Femoral Epiphysis. Journal of pediatric orthopedics, 35(6), 565–570. https://journals.lww.com/pedorthopaedics/abstract/2015/09000/pelvic_incidence_and_acetabular_version_in_slipped.5.aspx

  • Islam, A., Bohl, M. S., Tsai, A. G., Younesi, M., Gillespie, R., & Akkus, O. (2015). Biomechanical evaluation of a novel suturing scheme for grafting load-bearing collagen scaffolds for rotator cuff repair. Clinical biomechanics (Bristol, Avon), 30(7), 669–675. https://www.clinbiomech.com/article/S0268-0033(15)00143-6/fulltext

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