Overall, tadalafil and sildenafil had similar efficacy and safety, but men and their partners preferred tadalafil. You can learn more about the two ED treatments in our Cialis vs. Viagra guide. As with any medication, Cialis comes with possible side effects.

Brand names

Before prescribing Cialis, your doctor may send you for a blood test to check how well your kidneys and liver are working. This is because they’ll take your kidney and liver health into consideration when determining your dosage. For many people, their kidneys may not work as well as they age. So if you’re an older adult (age 65 years or older), it may take longer for your body to break down and clear Cialis from your system. Older adults’ bodies also be more sensitive in how they react to Cialis, which may increase their risk of side effects.

Erectile dysfunction explained

If you’re 70 years old, your doctor will likely start you on a low dosage of Cialis. If it works well for you, you’ll probably continue taking a low dosage. If it doesn’t work well for you or you develop bothersome side effects, your doctor will adjust your dosage. The goal is to find the lowest dosage that effectively treats your BPH symptoms or ED without causing bothersome side effects. If you have questions about what your Cialis dosage should be, talk with your doctor. The most common Cialis side effects include: Clinical trials show that most side effects are dose-dependent, meaning you’re more likely to get them with higher doses — and remember, Cialis 20 mg is the highest dose of the drug. Allergic reactions to Cialis aren’t common but they’re possible.

Product	Dosage	Quantity + Bonus	Price
Cialis Black	80mg	270 + 10 Pills	502.88€ 478.93€
Cialis Generic	20mg	120 + 8 Pills	188.15€ 179.19€
Cialis Professional	20mg	20 Pills	78.33€ 74.60€
Cialis Professional	20mg	120 + 4 Pills	291.68€ 277.79€
Cialis Generic	20mg	180 + 10 Pills	254.09€ 241.99€
Cialis Generic	60mg	20 Pills	65.61€ 62.49€
Cialis Generic	5mg	180 + 10 Pills	159.65€ 152.05€
Cialis Super Active	20mg	10 Pills	55.64€ 52.99€
Cialis Generic	20mg	270 + 10 Pills	335.21€ 319.25€
Cialis Professional	40mg	20 Pills	110.24€ 104.99€

Swelling of the lips, tongue, or throat Swelling of the lips, tongue, or throat There’s also a risk of priapism or prolonged erections — we’re talking for several hours here. It may sound great if you’re suffering from ED, but prolonged erections can be painful and cause irreversible damage to the penis.

Shipping Information

Depending on your preference and lifestyle, you may not want to take Cialis day in and day out. In fact, the 20 mg dose of Cialis should only be taken as needed. Side effects of Cialis are usually mild and should go away on their own — although they may be worse with higher doses. For example, in clinical trials, 11 percent of people taking tadalafil 10 mg got a headache, canadian pharmacy cialis 40mg whereas 15 percent of those taking tadalafil 20 mg got a headache. Some side effects have the same likelihood in both doses, such as flushing and limb pain.

Discover more about Cialis

If the side effects of Cialis 20 mg are too much, a healthcare provider may reduce your dose. If this is a particularly annoying side effect of other ED medications, switching to Cialis may be the answer. A 2017 systematic review and meta-analysis compared sildenafil (the generic of Viagra) and tadalafil. It found that tadalafil caused lower rates of flushing. Muscle aches and back pain were more common in tadalafil than sildenafil, though. If your erection lasts more than four hours, seek medical advice.

What other drugs will affect Cialis?

If you’re taking it as needed, you’ll likely be prescribed 5 mg, 10 mg, or 20 mg. The 10 mg strength is the typical starting dose, and it can be adjusted up or down depending on efficacy and side effects. But you won’t be taking 20 mg of Cialis daily. The lower doses of 2.5 mg and 5 mg are the daily doses of Cialis. For ED — which is when you struggle to get or keep an erection — Cialis works by cialis weekend pill dilating the blood vessels in the penis, which leads to a firmer erection.

Is a 40-mg dose of Cialis safe to take?

Cialis — 20 mg or otherwise — doesn’t just give you an erection, though. Some form of sexual stimulation is required to get hard. Cialis 20 mg may be a more effective treatment for ED than the 10 mg version. Clinical trials found that 68 to 77 percent of men taking 10 mg Cialis were able to have penetrative sex with their partner. Of those taking 20 mg Cialis, 76 to 85 percent were able to have penetrative sex. You may be more likely to get prolonged, painful erections from Cialis if you have: Anatomic deformations in the penis (like Peyronie’s disease) Anatomic deformations in the penis (like Peyronie’s disease) There’s also a small risk of vision loss.

Country	Legal Status	Notes
USA	Over-the-counter or prescription	Prescription required for 20 mg dose
UK	Prescription only	Available via doctor’s prescription
Canada	Prescription needed	Can be obtained with a doctor's script
Australia	Prescription-only	Legal for treatment of ED
India	Over-the-counter / prescription	Widely available, some formulations sold without prescription

If you notice any vision loss in one or both eyes, stop taking Cialis and seek medical help.

Cialis (Tadalafil) was first approved by the FDA in 2003 for ED.
The approval for BPH symptoms was granted in 2011.
A combination product for both ED and BPH symptoms was later approved.
It is one of the most widely prescribed medications for erectile dysfunction.
Patents for brand-name Cialis have expired in many markets.
This expiration allowed for the production of generic Tadalafil.
Generic versions must meet the same FDA standards for safety and efficacy.
This has increased access and reduced the cost for many patients.

This could be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), which is caused by a lack of blood flow to the optic nerve.

What Are the Differences Between Tadalafil and Cialis?

But not all research agrees — a smaller daily dose may be just as effective as the as-needed Cialis treatment. A systematic review and meta-analysis examined six randomized controlled trials involving more than 1,500 people and compared an as-needed tadalafil treatment to a once-a-day dose. The results showed that both treatments were about equally effective. While Cialis works similarly to Viagra®, Cialis lasts longer in your body. In fact, Cialis is known as the “weekend pill” for its long half-life.

Cialis form and strengths

Because you can pop one pill and have sex whenever you like over the next 36 hours (give or take a few hours), it offers more spontaneity. In comparison, avanafil only lasts up to six hours, and Viagra only lasts up to four hours. Clinical trials show that Cialis is effective for various severities and types of ED, including difficult-to-treat ED. If you find Cialis 10 mg isn’t working, a 20 mg tablet might do the trick. You don’t need to take it every day. Another serious side effect includes a sudden decrease in hearing or hearing loss. Again, get medical advice as soon as you notice this. There are also a few drug interactions you should know about. You shouldn’t take Cialis 20 mg (or any dose of the drug) at all if you’re taking nitrates.

Step	Description	Duration
Take with water	Swallow the pill whole, with a glass of water	Once daily
Timing	30 minutes to 1 hour before sexual activity	As needed
Food interactions	Can be taken with or without food, high-fat meals may delay effect	N/A
Maximum dosage	20 mg per day	N/A

The combo can cause your blood pressure to drop suddenly, resulting in dizziness, loss of consciousness, or even a heart attack or stroke.

Warnings & Precautions

The typical dose of Viagra for ED is 50 mg. Talk with your doctor to determine whether Cialis or Viagra is the better option for you. Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. You might have seen Cialis® — the popular erectile dysfunction (ED) medication — available in doses ranging from 2.5 mg to 20 mg. Cialis 20 mg is an effective erectile dysfunction treatment, but so are the lower doses of the drug.

Cialis for erectile dysfunction (ED)

Below, we’ll cover what Cialis 20 mg is used for, the benefits and side effects of this dose of Cialis, and how it compares to other strengths. Cialis is a brand name for tadalafil, a widely prescribed ED medication. Benign prostatic hyperplasia (BPH) or an enlarged prostate Benign prostatic hyperplasia (BPH) or an enlarged prostate Other forms of tadalafil are used to treat pulmonary arterial hypertension, a type of high blood pressure in the lungs, but Cialis is not prescribed for this condition. Cialis doses include 2.5 mg, 5 mg, 10 mg, and 20 mg. You can take Cialis on an as-needed basis and pop a pill before sex, or you can take a daily dose of Cialis so you’re always ready for action. Nitrates can be found in medications like isosorbide dinitrate or isosorbide mononitrate, which are used to treat prevent angina caused by heart disease. Also, watch out for recreational drugs that contain nitrates, like “poppers.” You also shouldn’t take Cialis if you take medications called guanylate cyclase stimulators, such as riociguat, which treats pulmonary hypertension.

Cialis can interact with many common medications beyond nitrates.
These include certain antibiotics, antifungal agents, and HIV medications.
Other blood pressure drugs and alpha-blockers are common interactants.
Always provide your doctor with a complete list of your medications.
This includes over-the-counter drugs, herbs, and supplements.
St. John's Wort may decrease the effectiveness of Tadalafil.
Other erectile dysfunction medications should not be used concurrently.
Using multiple PDE5 inhibitors increases the risk of severe side effects.

If you’re taking alpha-blockers (like doxazosin, tamsulosin, or alfuzosin) — which mainly treat high blood pressure or BPH — or CYP3A4 inhibitors (like the antibiotic erythromycin and the antifungal medication ketoconazole), which treat a wide variety of conditions, you may be prescribed a low dose of Cialis—probably not the 20 mg kind.

Clinical trials showed Cialis 20 mg improved erectile function in most men.
Improvement was measured using validated questionnaires like the IIEF.
Many men were able to achieve and maintain an erection sufficient for intercourse.
Patient and partner satisfaction scores were significantly improved.
The medication also significantly improved symptoms for men with BPH.
It reduced the International Prostate Symptom Score (IPSS) in studies.
The most common side effects in trials were headache and dyspepsia.
The incidence of serious cardiovascular events was low.

It’s unclear whether it’s safe to take Cialis 20 mg or any dose of the drug with other PDE5 inhibitors, such as: Tell your prescribing healthcare provider about the medications or supplements you’re taking before trying Cialis. Beyond medications, watch out for how much you drink when you’re taking Cialis. If you have five or more alcoholic drinks, you may experience: And a weird one to watch out for: grapefruit and Cialis.

Cialis 20 mg offers a discreet, convenient option for ED.
It can be taken with or without food.
Never share Cialis pills with others.
Cialis can also treat benign prostatic hyperplasia.
Always inform your healthcare provider about other medications.
Avoid grapefruit and grapefruit juice when taking Cialis.

A 2020 study on rats found that grapefruit juice inhibits tadalafil metabolism — remember, that’s the active ingredient in Cialis. This can lead to you having more tadalafil in your system, which can increase your risk of side effects. You can learn more about what to avoid in our guide to tadalafil interactions. Finally, tell a healthcare provider about any medical conditions you have before taking Cialis so they can determine whether it’s safe for you. Heart problems like angina (chest pain caused by reduced blood flow to the heart), heart disease, or irregular heartbeats Heart problems like angina (chest pain caused by reduced blood flow to the heart), heart disease, or irregular heartbeats Cialis is available in a range of doses. Here’s what they’re usually prescribed for: Cialis 2.5 mg: If you’re taking Cialis daily, you might be prescribed a 2.5 mg dose.

What special precautions should I follow?

As ED treatments, both Cialis and Viagra can be taken occasionally (as needed) before sexual activity. The usual dosage for occasional Cialis use is one 10-mg tablet at least 30 minutes before anticipated sexual activity. The usual dosage for occasional Viagra use is one dose 1 hour before sexual activity. Cialis is also approved for once-daily dosing for ED, but Viagra is not. This is because the effects of Cialis on ED can last much longer than Viagra’s effects.

Cialis form

One dose of Cialis can help with erectile function for up to 36 hours. In comparison, Viagra’s effects can last up to 4 hours. But on average, its effects start to reduce 2 to 3 hours after you take a dose. The typical dose for once-daily Cialis for ED is 2.5 milligrams (mg) to 5 mg. When used as needed for ED, the usual Cialis dose is 10 mg (with a maximum daily dose of 20 mg). If 2.5 mg isn’t effective and you don’t have any bothersome side effects, the dose may be increased to 5 mg. Cialis 2.5 mg: If you’re taking Cialis daily, you might be prescribed a 2.5 mg dose. Cialis 5mg: You may be prescribed a 5 mg daily dose of Cialis for BPH.

Cialis 20mg Daily Use Versus On-Demand Dosing