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.
Cialis is the brand name for the FDA-approved drug tadalafil, a PDE5 inhibitor commonly used to treat erectile dysfunction.
Affecting around 30 million men in the U.S. alone, erectile dysfunction is a sexual dysfunction that makes it difficult to get or maintain an erection long enough or hard enough for satisfying sex. Some men with ED are never capable of getting erections when untreated. Others are only capable of getting erections sometimes.
Similar to sildenafil, the active ingredient in Viagra, tadalafil was originally developed to treat high blood pressure. However, clinical trials revealed these drugs had an unusual side effect: induced erections. This happy accident led to the improvement of sex lives around the globe.
Like other PDE5 inhibitors, Cialis blocks an enzyme known as phosphodiesterase type 5 (PDE5) in the spongy erectile tissues of the penis. This inhibiting effect relaxes the smooth muscle cells of the arteries supplying the penis, enabling better blood flow into the erectile tissues. Better blood flow = harder and longer-lasting erections (but only with sexual stimulation).
Cialis works within 30 minutes and has a long duration of action, which means it remains active in the body (for up to 36 hours). This means that if you take the medication early in the day, it can still help you get an erection if you attempt to have sex later.
“For patients who take Cialis only when they need it, that means that they don't need to worry nearly as much about timing sex with medication ingestion,” says Dr. Peter J. Stahl, MD, SVP of Men’s Sexual Health & Urology at Hims & Hers. “They can take it before they go out on a date and feel confident for the entire evening and even into the next day. Cialis's long duration of action also allows it to be taken every day as part of a regular routine so that patients don't have to worry about taking medication before sex and are ready for spontaneous sex 24/7.”
If you’re prescribed Cialis, always follow your healthcare provider’s guidance. They’ll work with you to determine the proper dosage based on how you plan to take it. They may start you on a smaller dose and gradually increase it if you’re not seeing results.
Remember that dosage also depends on whether you take the medication daily or as needed. If you’re taking Cialis as needed, the typical starting dose is 10 mg, but it can be increased to Cialis 20 mg if necessary.
If you take Cialis daily, you’ll take a much lower dose. A typical starting dose is 2.5 mg and can be increased to 5 mg if needed.
For as-needed Cialis, you’ll usually take the medication around 30 minutes before sex. But remember, the medication can last up to 36 hours, so if you take it well in advance, it can still work in your favor.
For daily Cialis, you’ll want to take the medication at the same time each day.
Cialis is one of the most popular erectile dysfunction medications. If you’re having difficulty getting or maintaining an erection long enough for satisfying sex, Cialis improves your erectile function by increasing blood flow to the penis. As previously mentioned, it can be taken daily or as needed before sex. In addition to standard tablets, Cialis can also be taken as a chewable ED med.
Tadalafil isn’t just an ED medication. It’s also sometimes prescribed for symptoms of benign prostatic hyperplasia (BPH), or enlarged prostate, under the brand name Adcirca®. BPH is common in older men and typically carries symptoms of lower urinary tract problems, which can become bladder problems over time.
Tadalafil can also treat pulmonary arterial hypertension (PAH), a form of high blood pressure affecting the arteries in the lungs.
Studies show that PDE5 inhibitors like Cialis successfully treat ED in 60–70 percent of the population. (That’s a lot!)
In one meta-analysis of the long-term efficacy of tadalafil, research revealed that daily use offered a better effect on ED than as-needed for long-term treatment. Daily tadalafil also had a lower incidence of side effects. Moreover, daily tadalafil has been shown to have a “cardioprotective” effect of decreasing the incidence of heart attack, stroke and mortality in men. While surprising, this also supports its daily use.
Some people consider Cialis superior to Viagra because it lasts longer in the body. Another advantage is that you don’t have to time your medication around meals. While Viagra’s effects can be inhibited if you take the drug after eating a large meal (or fatty foods), you can take Cialis with or without food, and the medication will still work as it should.
The cost of Cialis varies depending on dosage and how you decide to take the medication.
At Hims, we offer access to generic Cialis starting at $79/month for daily use and $36/month for as-needed use.
If you opt for brand-name Cialis, the daily use version starts at $1,045/month or $525 for as-needed.
What’s the difference between generic or brand-name Cialis? Not much. Both contain the active ingredient tadalafil and work the same way. The only real difference is the name (and the price tag).
Most tadalafil side effects are mild and resolve on their own over time.
They include:
Headaches. According to a 2008 review of studies on tadalafil, 15 percent of men who used this medication at its highest dose (20 mg) experienced headaches. If you’re prone to headaches after taking Cialis, our guide to treating headaches from ED drugs may help.
Indigestion. Indigestion and heartburn are other common side effects of tadalafil, which occur due to how tadalafil affects the gastrointestinal smooth muscles and also due to increasing gastrointestinal blood flow. Drinking more water or using antacid medicine may make this side effect easier to manage.
Heartburn. Cialis relaxes the lower esophageal sphincter, which may lead to heartburn. Drinking more water or using antacid medicine may make this side effect easier to manage.
Muscle aches. A small percentage of men who use Cialis experience muscle pain, including back pain. The discomfort tends to occur around 12 to 24 hours after taking the medication. Over-the-counter pain relief, like ibuprofen or aspirin, may help.
Facial flushing. Because Cialis dilates blood vessels, facial flushing can happen around your nose, cheeks, chin, and forehead. Around three percent of men who use Cialis experience facial flushing.
Nasal congestion. Tadalafil can affect nitric oxide levels inside your nasal cavity, giving you a stuffy nose. As with many other side effects of Cialis, nasal congestion tends to fade as your body processes the medication.
Nasopharyngitis. Some men who use Cialis to treat ED report cold-like symptoms after taking the medication because it affects the soft tissue inside the nose and throat.
Pain in limbs. In clinical trials, one to three percent of men who used Cialis reported leg pain and, on occasion, pain in their other limbs. This side effect was more common in guys who took 10 to 20 mg of Cialis daily.
In general, the common effects of daily tadalafil are similar to those when it’s taken as needed before sexual activity.
However, because daily-use Cialis is prescribed at a lower dose, some side effects appear less common and are generally less severe.
For instance, in clinical trials, 11 to 15 percent of men reported headaches from Cialis at a dose of 5 to 20 mg. In comparison, only three to six percent of men who took Cialis daily at a 2.5 or 5 mg dose reported headaches.
Other side effects, such as dyspepsia and back pain, were also reported less frequently by men prescribed Cialis for daily use.
Here’s where things get a little more serious. While most side effects mentioned above are relatively mild, the side effects below — although rare — require immediate care.
Serious adverse effects of Cialis might include:
Priapism. Priapism is a painful erection lasting four hours or longer. It’s a medical emergency that requires immediate attention to avoid damaging the erectile tissue. Though it’s possible to experience a prolonged erection after using Cialis, it’s highly uncommon.
Optic nerve damage. Tadalafil was linked to rare reports of NAION (non-arteritic anterior ischemic optic neuropathy) in a study of sildenafil and optic nerve damage. Optic nerve damage could cause or contribute to vision loss (including retinitis pigmentosa). Like priapism, this is a very infrequent side effect.
Loss of hearing. Cases of sudden hearing loss caused by Cialis are also very uncommon. Some evidence suggests that the reported cases may be linked to underlying medical conditions. If you take Cialis to treat ED and notice any changes in your hearing, it’s best to stop taking the medication and seek medical advice.
Allergic reactions. It’s possible to have an allergic reaction to tadalafil or other inactive ingredients used in the manufacturing process. Common symptoms include hives, rash, swelling of the lips, throat, and tongue, and difficulty breathing or swallowing.
Other uncommon side effects of Cialis include chest pain, ringing in the ears, skin issues, and high blood pressure.
Tadalafil side effects aren’t the only concern when taking this drug.
As mentioned, Cialis can interact with other PDE5 inhibitors for ED, as well as medications prescribed to treat hypertension (high blood pressure), fungal infections, heart disease, heart failure, bleeding disorders, ulcers, and other medical conditions.
Be sure to share any prescription drugs you’re taking with your healthcare provider before starting this medication.
Tadalafil can interact with nitrates used to treat hypertension, angina (chest pain), and other heart problems. This could cause abnormally low blood pressure that may lead to loss of consciousness, heart attack, or even cardiac arrest.
If you take nitrates like nitroglycerin, isosorbide dinitrate, or isosorbide mononitrate to treat hypertension (high blood pressure) or angina, you shouldn’t take Cialis.
Besides nitrates used to treat cardiovascular conditions, ED medications can interact with certain recreational drugs that contain nitrates, like amyl nitrate “poppers.”
Cialis can interact with some oral antifungal medications, like itraconazole or ketoconazole, used to treat ringworm, dandruff, or 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, like the antibiotic erythromycin, may also interact with Cialis.
Grapefruit juice can also be a problem. If you want to take Cialis at night, you may have to stop eating grapefruit in the morning.
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 10 mg no more than once per 72 hours — or a daily dosage of 2.5 mg — if you’re prescribed any other medication that inhibits CYP3A4.
Other medications may also interact with Cialis, including:
Ritonavir. This antiretroviral medication inhibits CYP3A4 and may increase the effects of Cialis in the body.
Alpha-blockers. When taken with Cialis, alpha-blockers lower blood pressure. These medications are frequently prescribed to manage high blood pressure, BPH, and other conditions. This includes Flomax® (tamsulosin HCl), Cardura® (doxazosin mesylate), and Jalyn® (dutasteride and tamsulosin HCl).
Other PDE5 inhibitors. Other PDE5 inhibitors, such as sildenafil, may interact with Cialis and further lower blood pressure. .
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 ED pills:
Make sure you get them from a reputable source.
Don’t take street drugs or gas station supplements.
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 for treating ED. Although some online vendors advertise liquid versions of Cialis, these products are not regulated in the United States, so it’s best to stay away from them.
Although there’s no simple, one-size-fits-all way to eliminate side effects from Cialis completely, you can do several other things to reduce your side effect risk.
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, including the dreaded “whiskey dick.”
The best way to do this is to avoid any alcohol consumption. But if you typically drink while out on dates or as part of your everyday lifestyle, cutting your intake to one to two small servings can help.
Drug labels exist for a reason. Most potential side effects of Cialis are dose-dependent, meaning they become more common at higher doses. 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.
Cialis is a long-lasting ED medication that’s not intended for use more than one time a 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 your medication, don’t take a second dose of tadalafil. Rain-check sexy time if needed, and get in touch with your healthcare provider about potentially adjusting your dosage or trying a new ED med.
Cialis (tadalafil) is one of the most popular ED drugs for good reason. It’s approved by the FDA, proven to work, and lasts longer in the body than other ED drugs, making it appealing for as-needed or daily use. To recap:
Cialis increases blood flow to the penis. Like other PDE5 inhibitors, Cialis relaxes the smooth muscle in the penis to increase blood flow, enabling you to get or maintain better, longer-lasting erections.
Tadalafil has other uses. Tadalafil, the active ingredient in Cialis, is also prescribed for enlarged prostate and pulmonary arterial hypertension.
You may experience side effects with Cialis. If you’re prescribed Cialis for erectile dysfunction or benign prostatic hyperplasia and notice a concerning or problematic side effect, talk to your healthcare provider as soon as possible. They may suggest adjusting your dosage.
Other ED drugs can work if Cialis doesn’t. In some cases, your provider may suggest switching to another ED drug, like sildenafil (Viagra), vardenafil (Levitra®), or avanafil (Stendra®). These medications are shorter-acting than Cialis, so any side effects you experience may fade away sooner.
If you think Cialis can help improve your sex life, schedule an online consultation with a licensed healthcare provider to determine if prescription drugs are appropriate for your symptoms.
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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.