Sildenafil vs tadalafil: what’s the difference?

Sildenafil and tadalafil: the practical differences

1. How long do they work?

Sildenafil usually provides a window of support lasting several hours. Apotheek.nl describes an effect that wears off after about four hours; a four-to-six-hour window is often used as a practical estimate. Tadalafil can remain effective for up to around 36 hours. Timing varies between people.

That longer window explains tadalafil’s nickname, the weekend pill. It is a nickname, not a promise of an entire weekend of effects. And, importantly, a longer duration does not mean an erection lasting all that time. Erections should still come and go with arousal.

2. When do you take them?

Sildenafil is normally taken about an hour before sexual activity. Many people notice an effect within 30–60 minutes. A heavy or fatty meal can delay absorption, so a large dinner may change the timing.

On-demand tadalafil is taken at least 30 minutes before anticipated sex. Food has less influence on its absorption. Neither medicine works to a guaranteed stopwatch, and taking more does not make it a reliable instant solution.

3. Is tadalafil always taken every day?

No. Tadalafil can be prescribed on demand or as a low-dose daily treatment. These are different regimens. The official Cialis information describes 10 mg on demand, sometimes increased to 20 mg by a doctor, and a separate daily regimen of 5 mg that may be reduced to 2.5 mg.

Continuous daily use of the 10 mg or 20 mg on-demand doses is not recommended in that product information. Higher-strength tablets are not a shortcut to a daily regimen. Your prescriber should decide the dose and review whether daily treatment remains appropriate.

Sildenafil is usually taken as needed, with a maximum recommended frequency of once daily for erection problems. The usual starting dose in the Viagra information is 50 mg; depending on the individual, a doctor may use 25 mg or up to 100 mg. These figures describe authorised medicines, not a personal prescription.

4. Which has fewer side effects?

There is no universal winner. Both medicines can cause headache, flushing, indigestion, nasal congestion and dizziness. Visual changes can occur with sildenafil; back pain and muscle aches are recognised with tadalafil.

Different enzyme selectivity does not make tadalafil harmless or sildenafil inherently damaging to the brain or heart. What matters is your individual response, dose, medical history and other medicines. A longer-lasting medicine can also mean side effects do not disappear as quickly.

Important safety points for both

Do not combine either medicine with nitrates or poppers. A dangerous fall in blood pressure can result. Tell your doctor about all medicines and supplements, including treatments for blood pressure, prostate symptoms and heart disease. Do not stop prescribed heart medication to use an erection medicine.

Seek urgent medical help for chest pain, sudden loss of sight or hearing, or an erection lasting four hours or longer. Tell the clinician which medicine you took and when. Do not take a nitrate for chest pain after an erection medicine unless an emergency clinician specifically directs your treatment.

Read more

Visit the English knowledge centre. Our longer sildenafil guide and tadalafil guide are currently in Dutch.

Which option fits your life?

You do not need to turn intimacy into a timetable. But choosing an erection medicine involves more than deciding how spontaneous you want to be.

Ask your doctor about the likely cause of your erection problems, whether treatment is suitable with your current medicines, how often you expect to use it and what to do about side effects. Mention the dose you have already tried rather than simply asking for something stronger.

A longer window may be useful when you prefer flexibility. A shorter-acting option may suit occasional use. Neither is automatically the right choice for everyone, and persistent erection problems deserve an assessment rather than repeated self-experimentation.

Frequently asked questions

Here are the questions we hear most often. For questions about a particular treatment, your own doctor or pharmacist is the right person to assess what is suitable.