Dr Clare Morrison

Article by Dr Clare Morrison

Tadalafil Vs Sildenafil: Which Is Better?

Tadalafil and Sildenafil are two of the most popular treatments for erectile dysfunction, but you may know them better by their brand names — sildenafil is the generic version of Viagra, and Tadalafil is the generic version of Cialis. To help you find out which is the best option for you, here’s our expert guide to both treatments.  

What is Tadalafil?

Tadalafil is the generic name of the drug Cialis. It comes in two forms: daily doses and on-demand pills.

Tadalafil Daily is a low-dose tablet taken once a day to help you get an erection whenever you’re aroused. 

On-demand doses of Tadalafil have the same effect, but they’re taken 15-20 minutes before sex and help you get erections for a 36-hour period, so you don’t need to take them every day.

What is Sildenafil and how do erectile dysfunction treatments work?

Sildenafil is the generic version of Viagra, the best-known treatment for erectile dysfunction.

Like Tadalafil, the type of drug in Sildenafil is known as a PDE5 inhibitor. These medications help relax the smooth muscle around your blood vessels, increasing blood flow to your penis and helping you get an erection when you’re aroused.

PDE5 inhibitors don’t affect your sexual desire, just the physical aspect of erectile dysfunction. 

Does Tadalafil work faster than Sildenafil?

Although both medications are fast-acting, Tadalafil takes less time to work than Sildenafil. You usually feel the effects of Sildenafil within 20-30 minutes, whereas Tadalafil can work in only 15-20 minutes.

Tadalafil Daily, a lower daily dose, can help you get an erection any time throughout the day.

Does Tadalafil last longer than Sildenafil?

Tadalafil can remain in your body for up to 36 hours, earning it the nickname “the weekend pill”. This means you don’t need to pause any sexual activity to take a pill, you can take it in advance and be spontaneous. 

One dose of Sildenafil will stay in your body for around 4 hours, so you need to take it 30-60 minutes before sex to make the most of its effects. 

Is Sildenafil more effective than Tadalafil?

Both medications have a high success rate, helping the majority of men to regain control over their erections. In clinical trials, over 90% of men said Sildenafil improved their erections. A study on Tadalafil found that 81% of men experienced harder erections after taking it.

Does Tadalafil have fewer side effects than Sildenafil?

Because these drugs work in the same way, they share many of the same common side effects, including: headaches, muscle aches, back pain, facial flushing and indigestion. In most cases, these settle after an hour.

Contact your doctor for urgent medical attention if you experience any of these severe side effects while taking Tadalafil or Sildenafil:

  • Chest pain
  • Blurred vision
  • Sudden hearing loss
  • Fast heart rate
  • High or low blood pressure
  • Severe allergic reaction

Choosing a treatment

Both of these treatments are equally effective at improving your blood flow to help you get harder erections. They also have very similar common side effects.

Tadalafil is also available in both daily and on-demand form, which could make it easier for you to find a dose that suits your lifestyle.

Erectile dysfunction treatments need to be prescribed by a medical professional.

Tadalafil (Cialis) 

Sildenafil (Viagra)

Price Prices start from £20 Prices start from £20
Prescription required? Yes Yes
Active ingredient Tadalafil Sildenafil
Dosage Available in 2.5, 5, 10 and 20mg tablets Available in 25, 50 and 100mg tablets
Effectiveness Works for >80 percent of men Works for >80 percent of men
How fast does it work? Works as quickly as 15-20 minutes. Tadalafil Daily is also available, which works throughout the day. Works within 30 minutes of taking the pill.
How long does it last? Effects can last up to 36 hours Remains active for four to six hours
How to take May be taken with or without food. Be careful to avoid taking with greasy or fatty foods, or eating or drinking grapefruit, as this can affect how the drug works. Best if taken on an empty stomach as food can slow absorption and reduce effectiveness. Be careful to avoid eating or drinking grapefruit, as this can affect how the drug works.
Benefits Is available in lower doses and is long-lasting – which means you won’t need to time your sexual activity. Has been around much longer than other treatments, and has a proven track record for safety and success.
Side effects Facial flushing, headache, indigestion, and a stuffy or runny nose. Facial flushing, headache, indigestion, and a stuffy or runny nose. May also cause a green-blue visual tinge.

Find out what treatment is suitable for you on our website.

Dr Clare Morrison
Dr Clare Morrison
Experienced General Practitioner in Hampshire since 1995, with particular interest in Nutrition, Obesity and Smoking Cessation.
Originally published November 15 2018, updated May 01 2024