Dr Clare Morrison

Article by Dr Clare Morrison

Tadalafil vs Sildenafil: Which is better?

Tadalafil and Sildenafil are two popular generic erectile dysfunction treatments. Sildenafil is the generic version of the original erectile dysfunction drug Viagra and Tadalafil is the generic version of Cialis. We compare several factors including how fast they work, cost, duration, effectiveness and more. Find out which treatment is more effective for you!



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 81 percent of men Works for 82 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 thirty 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
Selling point 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. Generic Sildenafil provides a very cost-effective treatment option
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

What is Tadalafil?

Tadalafil is the generic name of the drug Cialis. Tadalafil Daily is a low dosage tablet which is taken once a day and allows you to achieve an erection at any time of the day or night. Tadalafil 36-hour is taken 15-20 minutes before sex and works for as long as 36 hours.

What is Sildenafil?

Sildenafil is the generic version of Viagra, the best-known treatment for erectile dysfunction and has been licensed for use for over 15 years. Millions of men across the world have found it to be a very effective treatment. Since 2013, Viagra has been available as a generic medicine called Sildenafil. As a consequence, the price for Sildenafil has fallen substantially.

How do Tadalafil and Viagra work?

Tadalafil, like Sildenafil is what is known as a PDE-5 inhibitor. When sexually stimulated, the PDE-5 class of drugs maintains a relaxed muscle state and increases the flow of blood to the penis to facilitate an erection. PDE-5 inhibitors do not increase interest or sexual desire and are only used to treat the physical problems associated with erectile dysfunction.

Does Tadalafil work more quickly than Sildenafil?

Although both have a fast onset of action, Tadalafil works slightly faster than Sildenafil. While Sildenafil usually takes about 20-30 minutes, Tadalafil can work in 15-20 minutes. Tadalafil is also available as Tadalafil Daily, which is taken once a day, and will enable you to achieve an erection anytime throughout the day.

Winner: Tadalafil

Does Tadalafil last longer than Sildenafil?

Tadalafil has a longer duration of action than Sildenafil, and can remain in the body for up to 36 hours. This has earned it the reputation of “The Weekend Pill”. This benefits you because you don’t need to pre-plan your dosage close to any expected sexual activity, but instead can utilise its effects up to 12, and sometimes 36 hours after taking it.

Winner: Tadalafil

Is Sildenafil more effective than Tadalafil?

Both medications have a high success rate, helping the majority of men to regain control over their erection. In clinical trials for Sildenafil, Sildenafil 100mg  was effective at treating 82 percent of patients; while in clinical trial data for Cialis, 81 percent of patients found that Tadalafil improved their erections. The clinical trial data indicates that both are effective and there is no significant difference between the two drugs.

Winner: Draw

Does Tadalafil have fewer side effects than Sildenafil?

As both drugs work in the same way, they share many of the same side effects. These include face flushing, headaches and indigestion.  However, Sildenafil also has a few other effects that don’t seem to affect users of Tadalafil to the same extent, such as rashes, visual disturbances and diarrhoea.  Headaches also occur more commonly with Sildenafil, but may last longer with Tadalafil.  If any of these affect you after taking a dose of Sildenafil, Tadalafil may be a better option.

Winner: Tadalafil

Conclusion: Which is Better – Tadalafil vs Sildenafil?

Tadalafil is a more modern, effective treatment for erectile dysfunction. Tadalafil appears to offer advantages over Sildenafil when it comes to the most desirable attributes for an erectile dysfunction medication, including duration of action, onset of action, and side effects.

Winner: Tadalafil

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 2017, updated March 10 2020