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Key takeaways
Cialis and Viagra are both PDE5 inhibitors used to treat erectile dysfunction, with Cialis also approved for benign prostatic hyperplasia (BPH).
Cialis offers a longer duration of action, up to 36 hours, and can be taken with or without food, whereas Viagra’s effects last for about 4 hours, and its absorption can be affected by food.
Both medications have similar side effects and drug interactions, but Cialis may cause diarrhea and arm or leg pain, while Viagra may lead to more nausea, dizziness, and rash.
Cialis and Viagra have similar efficacy for ED, but individual preference for dosing convenience and side effect profiles can guide the choice between them.
Drug overview and main differences | Dosages | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | Alternatives | FAQ
If you are experiencing erectile dysfunction (ED), there are many options available to help you. Treatment options for ED include medications and non-drug treatments, such as lifestyle changes and talk therapy. Cialis (tadalafil) and Viagra (sildenafil) are two of the most commonly prescribed medications for ED.
Cialis and Viagra are brand-name prescription drugs that can treat ED.
They are part of a class of medications called phosphodiesterase-5 (PDE5) inhibitors that work by increasing blood flow to the penis. Other similar drugs include Levitra (vardenafil) and Stendra (avanafil). While they can help treat occasional or long-term ED, PDE5 inhibitors will not treat any underlying medical condition that can contribute to ED, such as diabetes or heart disease.
As always, it’s important to consult a healthcare provider before starting a new medication. Continue reading to learn more about using Cialis or Viagra, their potential side effects, and other information.
What are the main differences between Cialis and Viagra?
Cialis (Cialis coupons | What is Cialis?), which is manufactured by Eli Lilly, was FDA-approved in 2003 as a brand-name drug containing tadalafil. It is prescribed to treat erectile dysfunction and benign prostatic hyperplasia (BPH). Cialis can be taken as needed before sexual activity or once daily, with effects lasting up to 36 hours. Cialis reaches maximum levels in the body between 30 minutes and six hours after taking it. It can be taken with food or on an empty stomach.
Viagra (Viagra coupons | What is Viagra?), also known by its generic name sildenafil, was approved by the FDA in 1998 and is a popular drug made by Pfizer to treat ED. It can be taken as needed before sexual activity, with maximum levels of the drug reached within 30 minutes to two hours after taking it. Eating a high-fat meal with Viagra may reduce the absorption of the drug.
| Main differences between Cialis vs. Viagra | ||
|---|---|---|
| Cialis | Viagra | |
| Drug class | Phosphodiesterase type 5 (PDE5) inhibitor | Phosphodiesterase type 5 (PDE5) inhibitor |
| Brand/generic status | Brand and generic version available | Brand and generic version available |
| What is the generic name? What is the brand name? |
Tadalafil Cialis |
Sildenafil Viagra |
| What form(s) does the drug come in? | Oral tablet | Oral tablet |
| What is the standard dosage? | ED: 10 mg before sexual activity Once-daily use for ED: 2.5 mg by mouth daily BPH or BPH with ED: 5 mg taken at the same time every day |
ED: 50 mg before sexual activity |
| How long is the typical treatment? | Short-term or long-term treatment as advised by a healthcare provider | Short-term or long-term treatment as advised by a healthcare provider |
| Who typically uses the medication? | Adult men aged 18 years and older | Adult men aged 18 years and older |
What is the standard dosage of Cialis and Viagra?
Cialis dosage
The usual starting dosage for Cialis is 10 mg as needed before expected sexual activity. It starts working within 30 to 45 minutes after taking it. The dosage may be increased to 20 mg or decreased to 5 mg as needed depending on the response to treatment.
Cialis can also be taken once daily if you have ED, BPH, or ED and BPH. For ED, Cialis can be taken as 2.5 mg once daily. The maximum dosage for once-daily treatment for ED is 5 mg per day. For BPH alone or BPH and ED, Cialis can be taken as 5 mg at around the same time every day.
Cialis can be taken with or without food. It should not be taken more than once daily.
Viagra dosage
Viagra is typically prescribed to be taken as a 50 mg tablet as needed around one hour before sexual activity. Viagra generally starts working between 30 minutes and four hours after taking it. The dosage may be increased to 100 mg or decreased to 25 mg as needed based on the treatment response or side effects experienced.
Viagra can be taken with or without food. However, a high-fat meal may reduce the absorption of Viagra into the body. If you eat a high-fat meal with Viagra, you may have to wait longer for the drug to start working. Viagra should not be taken more than once daily.
Conditions treated by Cialis vs. Viagra
Cialis is primarily used to treat ED. However, it is also approved to treat signs and symptoms of an enlarged prostate, also called benign prostatic hyperplasia (BPH). Tadalafil, the active ingredient in Cialis, is also available as a brand-name drug called Adcirca, which is used to treat pulmonary arterial hypertension (PAH), or high blood pressure in the lungs. Tadalafil can also be used off-label for Raynaud’s phenomenon, a rare blood vessel disorder, and female sexual arousal disorder.
Viagra is only FDA-approved to treat ED. Sildenafil citrate, the active ingredient in Viagra, is also used to treat PAH under the brand name Revatio. Viagra is sometimes used off-label to treat Raynaud’s phenomenon and female sexual arousal disorder.
Cialis and Viagra have also been prescribed to treat other sexual problems in men regarding ejaculation, orgasm, and overall sexual satisfaction. For instance, Cialis has been shown to help improve ejaculation and the ability to reach an orgasm in men. Viagra may also help men who have problems with early ejaculation by improving ejaculatory control.
| Conditions treated by Cialis and Viagra | ||
|---|---|---|
| Condition | Cialis | Viagra |
| Erectile dysfunction (ED) | Yes | Yes |
| Benign prostatic hyperplasia (BPH) | Yes | No |
| Raynaud’s phenomenon | Off-label | Off-label |
| Female sexual arousal disorder | Off-label | Off-label |
| Premature ejaculation | Off-label | Off-label |
Is Cialis or Viagra more effective?
Cialis and Viagra are both effective treatments for erectile dysfunction. Most of the differences between the two drugs have to do with how long their effects last and how they are dosed. Still, clinical trials comparing the drugs have provided some interesting insights.
Although Cialis and Viagra are both effective, Cialis may be preferred for its once-daily dosing. Cialis may also be preferred over Viagra in men who have BPH in addition to ED. Viagra may be preferred for its short half-life in men who are able to plan their sexual encounters or those who only need ED treatment on occasion.
In a meta-analysis pooling 16 different trials and analyzing over 5,000 patients, Cialis and Viagra were found to be similarly effective and safe. Results on effectiveness were based on the International Index of Erectile Function (IIEF)-EF scale, which is widely used to assess erectile function. Both drugs had similar incidences of side effects. However, those taking Cialis experienced improved sexual confidence and preferred it over Viagra for its long-acting effects.
If you experience ED, it’s important to consult a doctor to determine which treatment option may be best for you. One medication may be more effective or preferred over the other, depending on your overall condition.
Coverage and cost comparison of Cialis vs. Viagra
Brand-name Cialis is not typically covered by Medicare and most insurance plans. Some plans, however, may cover generic tadalafil. The average retail cost of Cialis is around $400 for thirty 5 mg tablets, although the cost can vary depending on the quantity and dosage prescribed. With a SingleCare Cialis coupon, you may be able to receive a discount at participating pharmacies.
Brand-name Viagra is not usually covered by Medicare and most insurance plans. Check your insurance plan’s formulary because some plans may cover generic sildenafil. The average retail cost of Viagra is around $90 for a 100 mg tablet. However, the cash price can depend on the quantity prescribed. A SingleCare Viagra coupon may help you lower the cash price of your prescription.
| Cialis (tadalafil) | Viagra (sildenafil) | |
| Typically covered by insurance? | No | No |
| Typically covered by Medicare? | No | No |
| Standard dosage | 2.5 mg tablets (supply of 30) | 25 mg tablets (supply of 30) |
| Typical Medicare copay | $275 | $140-$400 |
| SingleCare cost | $20-$100 | $75-$140 |
Common side effects of Cialis and Viagra
Cialis and Viagra share several common side effects, such as headache, indigestion, muscle pain, back pain, and nasal congestion. Other possible side effects of these drugs include abnormal changes in vision, nausea, dizziness, and rash.
Both ED medications can also cause some degree of flushing, which is a warm feeling with a blushed skin tone, especially on the face. Flushing is caused by the vasodilator effects of these drugs, which relaxes smooth muscles in the blood vessels to increase blood flow.
In addition to these side effects, Cialis may also cause diarrhea and some pain in the arms or legs. Viagra may cause more nausea, dizziness, and rash than Cialis.
Serious side effects of Cialis and Viagra include an erection that doesn’t go away (priapism) and sudden loss or decrease in vision or hearing. Other serious side effects may include cardiovascular complications, such as heart attack and stroke, when taken with certain drugs (see Drug Interactions).
| Side effects of Cialis vs. Viagra | ||||
|---|---|---|---|---|
| Cialis *10 mg tablet |
Viagra *50 mg tablet |
|||
| Side Effect | Applicable? | Frequency | Applicable? | Frequency |
| Headache | Yes | 11% | Yes | 21% |
| Indigestion | Yes | 8% | Yes | 9% |
| Muscle pain | Yes | 4% | Yes | 2% |
| Back pain | Yes | 5% | Yes | 4% |
| Nasal congestion | Yes | 3% | Yes | 4% |
| Flushing | Yes | 3% | Yes | 19% |
| Pain in the arms or legs | Yes | 3% | No | – |
| Abnormal vision | Yes | <0.1% | Yes | 2% |
| Nausea | Yes | <1% | Yes | 3% |
| Dizziness | Yes | <2% | Yes | 4% |
| Rash | Yes | <2% | Yes | 2% |
*Consult a doctor or pharmacist for all possible side effects.
Source: DailyMed (Cialis), DailyMed (Viagra)
Drug interactions of Cialis vs. Viagra
PDE5 inhibitors like Cialis and Viagra have similar drug interactions. The use of Cialis or Viagra should be avoided with certain medications that can decrease blood pressure. These medications include nitrates and guanylate cyclase stimulators. Taking nitrates or guanylate cyclase stimulators, such as riociguat, with Cialis or Viagra can cause dangerously low blood pressure (hypotension).
Combining a PDE5 inhibitor with alpha-blockers, antihypertensives, or alcohol may also lead to hypotension. Very low blood pressure could lead to dizziness, fainting, and an increased risk of heart attack or stroke.
Cialis and Viagra are both processed in the liver. Therefore, they should not be used with medications that alter the function of certain liver enzymes. CYP3A4 inhibitors, such as certain antibiotics, antifungals, and HIV protease inhibitor drugs, can increase the levels and possible side effects of Cialis and Viagra in the body. CYP3A4 inducers, such as certain anticonvulsants and antibiotics, can decrease the levels and overall effectiveness of Cialis and Viagra.
The use of Cialis or Viagra should also be avoided with alcohol and grapefruit juice. Consuming alcohol or grapefruit juice may increase the side effects of ED medications.
| Drug | Drug Class | Cialis | Viagra |
| Nitroglycerin Isosorbide dinitrate Isosorbide mononitrate Amyl nitrate Amyl nitrite Butyl nitrate |
Nitrate | Yes | Yes |
| Riociguat | Guanylate cyclase stimulator | Yes | Yes |
| Doxazosin Tamsulosin Terazosin Prazosin Alfuzosin |
Alpha blocker | Yes | Yes |
| Amlodipine Enalapril Lisinopril Metoprolol Losartan Valsartan |
Antihypertensive | Yes | Yes |
| Erythromycin Clarithromycin Telithromycin Rifampin |
Antibiotic | Yes | Yes |
| Ketoconazole Itraconazole |
Antifungal agent | Yes | Yes |
| Ritonavir Atazanavir Darunavir Indinavir Lopinavir Saquinavir |
Protease inhibitor | Yes | Yes |
| Phenytoin Carbamazepine |
Anticonvulsant | Yes | Yes |
*This may not be a complete list of all possible drug interactions. Consult a doctor with all medications you may be taking.
Warnings of Cialis and Viagra
The use of ED drugs, such as Cialis and Viagra, may increase the risk of heart attack or stroke in people with heart disease or related conditions.
Prolonged erections lasting longer than four hours are possible with ED medications. Erections that are painful and last longer than six hours indicate a condition called priapism. If you experience a prolonged erection with Cialis or Viagra, seek medical attention immediately.
Although rare, Cialis and Viagra can cause abnormal changes in vision or hearing. In more serious cases, these drugs can cause sudden hearing or vision loss. If you experience sudden hearing changes, stop taking Cialis or Viagra and contact your healthcare provider immediately.
Cialis and Viagra are not FDA approved for women or children younger than 18 years old.
Cialis and Viagra do not protect against sexually transmitted diseases (STDs). Consider other protective measures to prevent STDs while taking Cialis or Viagra.
Serious adverse effects may be common with counterfeit ED drugs. Counterfeit Viagra may contain other ingredients or incorrect amounts of the active ingredient. Counterfeit drugs are not approved by the FDA. Make sure you are getting safe and effective ED drugs from a reliable source.
Alternatives to Cialis and Viagra
Cialis and Viagra are not the only medications that can treat ED. The other PDE5 inhibitors FDA-approved to treat ED are Levitra (vardenafil) and Stendra (avanafil). These ED drugs may differ in how fast they work and how long their effects last. However, they may cause similar side effects and have similar drug interactions. It’s best to consult a healthcare provider if you’re considering a particular ED drug.
Levitra (vardenafil)
Levitra is a brand-name drug that contains the active ingredient vardenafil hydrochloride. The usual dosage is 10 mg as needed before sexual activity but not more than once per day. It may take around 60 minutes for Levitra to start working. Levitra can be taken with or without food. Levitra may cause fewer side effects than Viagra in some people. However, its effects last for around four hours, which is a similar duration to that of Viagra’s effects.
Stendra (avanafil)
Stendra is a relatively new PDE5 inhibitor used to treat ED. It contains the active ingredient avanafil. The usual dosage of Stendra is 100 mg as needed before sexual activity. What makes Stendra different from other PDE5 inhibitors is that it works more quickly; it can be taken as early as 15 minutes before sexual activity. Its effects last for around six hours. Stendra can be taken with or without food.
Frequently asked questions about Cialis vs. Viagra
What is Cialis?
Cialis, also known by its generic name tadalafil, is a prescription drug used for erectile dysfunction (ED). It can also treat men with an enlarged prostate, or benign prostatic hyperplasia (BPH). Cialis can be taken as needed or once daily with effects lasting up to 36 hours.
What is Viagra?
Viagra is also known by its generic name sildenafil. It is prescribed for erectile dysfunction (ED). Viagra is usually taken as a 50 mg tablet 30 minutes to 4 hours before sexual activity. It should be avoided with a high-fat meal which can reduce its absorption.
Are Cialis and Viagra the same?
Cialis and Viagra are in the same class of drugs called phosphodiesterase 5 (PDE5) inhibitors. However, they are not the same. Cialis contains tadalafil and Viagra contains sildenafil. They also have some different side effects and uses.
Is Cialis or Viagra better?
Cialis and Viagra are both effective for ED. Cialis may be preferred for its once-daily dosing and longer-lasting effects. If you experience erectile dysfunction and are looking for treatment, there are many doctors and specialists who can assess your ED and help you find the best option for your sex life.
Can I use Cialis or Viagra while pregnant?
No. Cialis and Viagra are not indicated for pregnant women. While some off-label uses have been reported for female sexual arousal disorder, women who are pregnant should not be taking ED medications.
Can I use Cialis or Viagra with alcohol?
It is not recommended to use Cialis or Viagra with alcohol. Alcohol can increase side effects such as dizziness and headache. Drinking alcohol with these drugs may result in low blood pressure.
How long does it take for Cialis to peak?
According to the FDA label, maximum levels of Cialis in the body are reached within 30 minutes and 6 hours after taking a single dose. Taking Cialis with or without food does not affect its absorption.
Does Cialis make you last longer?
Cialis does not affect your ability to last longer. It is used to help get and maintain an erection for sexual activity. Sexual stimulation or arousal is required for an erection with Cialis.
Can Viagra and Cialis be taken together?
Viagra and Cialis should not be taken together. Because they act in similar ways, taking them together can increase the risk of adverse side effects.