
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 cheapt cialis soft aches and back pain were more common in tadalafil than sildenafil, though.
| Side Effect | Severity | Common Symptoms | When to Seek Medical Advice |
|---|---|---|---|
| Headache | Mild to Moderate | Throbbing pains, scalp tenderness | If persistent or severe |
| Flushing | Mild | Warmth, redness in face or neck | Usually temporary |
| Upset Stomach | Mild | Nausea, indigestion | If severe or prolonged |
| Muscle Aches | Mild | Back or limb pain | Consult if pain worsens |
| Vision Changes | Rare | Blurred vision, color perception | Immediate medical attention |
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.
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, 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. 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. As with any medication, Cialis comes with possible side effects.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Cialis Super Active | 20mg | 90 + 10 Pills | 314.14€ 299.18€ | |
| Cialis Generic | 2.5mg | 60 + 4 Pills | 83.43€ 79.46€ | |
| Cialis Generic | 2.5mg | 20 Pills | 40.73€ 38.79€ | |
| Cialis Black | 80mg | 180 + 10 Pills | 356.64€ 339.66€ | |
| Cialis Generic | 5mg | 270 + 10 Pills | 205.81€ 196.01€ | |
| Cialis Generic | 5mg | 180 + 10 Pills | 159.65€ 152.05€ | |
| Cialis Generic | 5mg | 10 Pills | 29.39€ 27.99€ | |
| Cialis Generic | 20mg | 30 + 4 Pills | 68.05€ 64.81€ | |
| Cialis Generic | 10mg | 270 + 10 Pills | 308.71€ 294.01€ | |
| Cialis Generic | 20mg | 10 Pills | 31.49€ 29.99€ | |
| Cialis Generic | 2.5mg | 30 + 4 Pills | 51.95€ 49.48€ | |
| Cialis Original | 20mg | 22 + 2 Pills | 129.20€ 123.05€ | |
| Cialis Professional | 40mg | 120 + 4 Pills | 436.68€ 415.89€ | |
| Cialis Generic | 2.5mg | 270 + 10 Pills | 199.64€ 190.13€ |
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.
If you are contemplating Cialis for daily use, consider these questions and then discuss it with your doctor: If it's two or more times a week, a daily pill might be a reasonable choice, since the drug continually circulates in your bloodstream. A daily pill clears the path for sex at any time—if the drug works for you. (Remember, just like other ED drugs, it may not work for everyone). On the other hand, the 36-hour window offered by the nondaily version of Cialis might offer enough spontaneity. Have side effects of your current ED pill been bothering you?
Taking a daily low-dose pill may reduce side effects, though it may reduce effectiveness as well. In studies, the most common daily pill side effects were headache, muscle pain, indigestion, and back pain. Men taking Cialis for daily use can experience a worrisome drop in blood pressure if they drink too much. Ask your doctor if any medications or supplements you take might interact with a daily erectile dysfunction pill, including blood pressure drugs, antifungal drugs, and HIV drugs. Also, men taking nitrate medications are advised not to take any ED drugs.
While the manufacturer suggests that a 30-day supply of daily Cialis should cost about the same as eight pills of 36-hour Cialis a month, there's no way to enforce this. Check your insurance policy and local pharmacies for price information. – By Matthew Solan Executive Editor, Harvard Men's Health Watch As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. 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. If your erection lasts more than four hours, seek medical advice.
| Phase | Description | Duration | Effect Duration |
|---|---|---|---|
| Absorption | Tadalafil enters bloodstream quickly via GI tract | 30-60 mins | Up to 36 hours |
| Action | Enhances blood flow to penile tissue | Ongoing | Up to 36 hours |
| Metabolism | Liver processes Tadalafil | Several hours | - |
| Excretion | Primarily through feces and urine | 17-19 hours | - |
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.
Get the latest in health news delivered to your inbox! 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. 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. 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 dilating the blood vessels in the penis, which leads to a firmer erection. Cialis — 20 mg or otherwise — doesn’t just give you an erection, though. Some form of sexual stimulation is required to get hard. If you notice any vision loss in one or both eyes, stop taking Cialis and seek medical help. 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. 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. The combo can cause your blood pressure to drop suddenly, resulting in dizziness, loss of consciousness, or even a heart attack or stroke. 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. 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. 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. 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.
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. 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. 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. 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. 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. 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. If you have both BPH and ED (the two conditions are linked), you may also get a 5 mg daily dose of Cialis. Cialis 10 mg: For an as-needed ED treatment, you’ll most likely be prescribed a 10 mg dose of Cialis to get started. A healthcare provider may then increase your dose to 20 mg or decrease it to 5 mg depending on how you react to the medication and how well it works for you.
| Step | Instructions | Timing | Tips |
|---|---|---|---|
| Oral Administration | Swallow with water, with or without food | About 30-60 mins before activity | Take once per day for weekend coverage |
| Dose Adherence | Follow prescribed dose | Daily or as directed | Do not exceed recommended dose |
| Storage | Keep in a cool, dry place | Away from children | Avoid excessive heat or moisture |
| Alcohol Consumption | Minimize to avoid side effects | Before and after taking medication | Alcohol can reduce effectiveness |