Tadalafil 20 mg: Uses, cost, and side effects vs. other strengths

In this article:

• What is tadalafil 20 mg used for?
• Tadalafil 20 mg vs. other doses
• How long does tadalafil 20 mg last?
• Side effects of tadalafil 20 mg
• Tadalafil 20 mg vs 10 mg: What’s the difference?
• Tadalafil 20 mg price vs. other doses
• Who shouldn’t take tadalafil 20 mg?
• Is tadalafil 20 mg safe?

In this article

• What is tadalafil 20 mg used for?
• Tadalafil 20 mg vs. other doses
• How long does tadalafil 20 mg last?
• Side effects of tadalafil 20 mg
• Tadalafil 20 mg vs 10 mg: What’s the difference?
• Tadalafil 20 mg price vs. other doses
• Who shouldn’t take tadalafil 20 mg?
• Is tadalafil 20 mg safe?

Tadalafil is a generic oral medication prescribed for erectile dysfunction (ED) and benign prostatic hyperplasia (BPH), a condition that causes an enlarged prostate. It is also FDA approved to treat pulmonary arterial hypertension (PAH), a type of high blood pressure caused by narrowed arteries in the lungs. For ED, tadalafil can be taken as needed at a maximum dose of 20 mg. People taking the highest dose of tadalafil may have questions about safety and how it compares to lower doses. Here’s what to know about tadalafil 20 mg, including its uses, dosing, side effects, and cost.

What is tadalafil 20 mg used for?

“Tadalafil may be used daily at lower doses for more spontaneous activity or at higher doses as needed,” says Sanjay Razdan, MD, urologist and professor and chairman of the International Robotic Institute for Prostate Cancer in Miami, Florida. The right dose depends on the condition being treated and the response in the individual patient.

Erectile dysfunction (ED)

Generic tadalafil and its brand-name version, Cialis, were FDA approved to treat erectile dysfunction. They belong to a class of drugs called PDE5 inhibitors (phosphodiesterase 5 inhibitors). These drugs work by blocking an enzyme that breaks down molecules responsible for dilating blood vessels and increasing blood flow to the penis when sexually stimulated, helping produce an erection.

Tadalafil can be taken daily at doses ranging from 2.5 mg to 5 mg, or as needed in doses up to 20 mg. “The 20 mg as-needed dose is the maximum recommended dose for ED and is appropriate when lower doses (5 mg or 10 mg) have proven insufficient,” says Justin Houman, MD, urologist at Tower Urology at Cedars-Sinai Medical Center. The maximum daily dose of Tadalafil for ED is 5 mg. 

Benign prostatic hyperplasia (BPH)

Tadalafil is approved for daily use in people with BPH. It works by relaxing the smooth muscles around the prostate and bladder to relieve symptoms such as difficulty urinating. The recommended dose is 5 mg once daily, and it can be combined with other medications such as finasteride. The 5 mg daily dose also applies to people managing both ED and BPH. Men taking tadalafil 5 mg daily should not take an additional 20 mg before sexual intercourse. 

Pulmonary arterial hypertension (PAH)

Because of tadalafil’s effect on relaxing arteries, it can be helpful in people with PAH. People with PAH are typically prescribed a higher dose of 40 mg daily, taken as two 20 mg tablets. This dose may be adjusted downward to 20 mg daily in people with mild to moderate kidney disease or liver disease. Off-label, tadalafil has also been studied to improve PAH symptoms in premenopausal women. 

Off-label uses

Off-label, tadalafil can also be used for Raynaud’s phenomenon, a condition that causes blood vessels in the fingers and toes to narrow, and to prevent high-altitude pulmonary edema (fluid buildup in the lungs at high altitudes). There are also studies supporting its off-label use in women for sexual dysfunction, though it is not FDA approved for this.

Tadalafil 20 mg vs. other doses
Dose	Typical use	Frequency	Details
2.5 mg	ED	Once daily	Starting dose for daily use
5 mg	ED, BPH, ED + BPH	Once daily	Standard daily dose
10 mg	ED	As needed	Typical starting dose for as-needed use
20 mg	ED, PAH	As needed (ED); once daily (PAH)	Maximum as-needed dose for ED; adjusted starting dose for PAH with kidney/liver impairment

How long does tadalafil 20 mg last?

Tadalafil 20 mg should be taken at least 30 minutes before sexual activity and reaches peak concentration within two hours, though effects can begin as soon as 20 minutes after taking it. Tadalafil works for up to 36 hours, which is why it’s sometimes called the “weekend pill”. Someone taking it on a Friday night may still experience its erectile effects on Sunday.

Unlike sildenafil (brand-name Viagra), tadalafil can be taken with or without food without significantly affecting absorption. Heavy alcohol consumption may increase the risk of low blood pressure in people who are taking tadalafil, but it does not affect how long tadalafil works.

Tadalafil is metabolized in the liver by an enzyme called cytochrome P450 3A4 (CYP3A4), which breaks down many medications. Substances that affect this enzyme can impact tadalafil levels in the blood:

• CYP3A4 inhibitors, which slow the enzyme and raise tadalafil levels in the blood
• CYP3A4 inducers, which speed up the enzyme and lower tadalafil levels in the blood

Side effects of tadalafil 20 mg

“Higher doses carry a dose-dependent increase in side effects,” Dr. Houman says. The most common side effects of tadalafil 20 mg include:

• Headache
• Indigestion or upset stomach
• Nasal congestion 
• Flushing
• Muscle pain

Tadalafil also comes with the risk of serious side effects. People taking 20 mg tadalafil may be at risk of:

• Prolonged erections (priapism)
• Sudden loss of vision or hearing
• Fainting, chest pain, heart attack, or stroke
• Low blood pressure, which can lead to dizziness and fainting

“Nasal congestion and dyspepsia are more pronounced at higher doses. Priapism is rare, but a medical emergency, and higher doses theoretically increase risk,” Dr. Houman says. Contact your healthcare provider immediately if you experience any of these side effects.

Tadalafil 20 mg vs 10 mg: What’s the difference?

For ED, 10 mg is the typical starting dose for as-needed use, but the dose can be increased to a maximum dose of 20 mg if necessary. Both doses have been shown to be effective for ED, with only slight differences in side effect profiles. According to the drug label, people taking 20 mg tadalafil reported slightly more headaches (15% vs. 11%), indigestion (10% vs. 8%), and back pain (6% vs. 5%) compared to those taking 10 mg.

A 2007 study suggested that 20 mg tadalafil may improve severe ED symptoms better than 10 mg in men with related conditions such as cardiovascular disease, diabetes, or high blood pressure. A 2016 study supported these findings, suggesting that higher as-needed doses may offer more benefits for people with ED and a related condition.

Tadalafil 20 mg price vs. other doses

The average retail price of tadalafil is $974 for 90, 5 mg tablets without insurance, but the cost varies depending on location, pharmacy, dose, and quantity. A free SingleCare coupon can reduce the cost to $17 for 90, 5 mg tablets. 

Brand-name Cialis 20 mg costs $1,654 for 30 tablets, even with a SingleCare coupon, compared to just $35 for 90 tablets of generic tadalafil 20 mg. You can compare prices at pharmacies near you by searching for your prescription on SingleCare.com or the SingleCare app and entering your ZIP code.

Tadalafil cost comparison by dose
Dosage	2.5 mg (30 tablets)	5 mg (30 tablets)	10 mg (30 tablets)	20 mg (30 tablets)
SingleCare price	$9 at Kroger or Harris Teeter	$11 at Kroger or Harris Teeter	$10 at Kroger or Harris Teeter	$13 at Kroger or Harris Teeter
How to save	Get coupon

Who shouldn’t take tadalafil 20 mg?

People with a known allergy to tadalafil should not take it. Tadalafil also interacts with certain medications, including guanylate cyclase stimulators (drugs that relax blood vessels, such as riociguat) and nitrates such as nitroglycerin. “Patients should be counseled on the safety of tadalafil, especially avoiding use with nitrates and being cautious in those with cardiovascular disease,” Dr. Razdan says.

Tadalafil 20 mg may also not be appropriate for people with certain conditions, including:

• Those who experience chest pain (angina) after taking tadalafil or during sex
• Those who have had a heart attack within the last 90 days or a stroke within the last six months
• Those with uncontrolled arrhythmias (irregular heartbeat), low blood pressure (less than 90/50 mmHg), or uncontrolled high blood pressure
• Those who have consumed a large amount of alcohol

People with chronic kidney disease and a creatinine clearance of less than 30 mL/min should not take more than 5 mg once daily or 10 mg once every 48 hours. People with mild or moderate liver disease should not take more than 10 mg, and people with severe liver disease should not take tadalafil at all. People taking other PDE5 inhibitor drugs (like sildenafil or Viagra) should also avoid tadalafil.

There is limited research on the safety of tadalafil in pregnant or breastfeeding people, so it is generally not recommended for this population.

Is tadalafil 20 mg safe?

Tadalafil 20 mg is the highest recommended as-needed dose for ED and can also be used as part of a 40 mg daily dose for PAH. It is generally safe when taken as directed by a healthcare provider.

Compared to lower doses, people taking 20 mg tadalafil have a slightly higher risk of side effects such as headache, indigestion, and nasal congestion. Drug interactions and certain medical conditions may also make it unsuitable for some people.

Dosing is based on individual health history and response to the medication. Always consult a healthcare provider with any concerns about your tadalafil 20 mg prescription.

Expert takeaway 

“Seek emergency care if you have an erection that lasts over hours,” says Leslie Greenberg, MD, member of the SingleCare Medical Board and associate professor of family and community medicine at the University of Nevada, Reno. Dr. Greenberg advises using tadalafil with caution if you have sickle cell disease, multiple myeloma, leukemia, Peyronie’s disease (a condition when the erect penis is curved), a “crowded” optic disc, or a history of non-arteritic anterior ischemic optic neuropathy (NAION).