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. Tadalafil is the generic version of Cialis, and sildenafil is the generic version of Viagra (the 'little blue pill').

To help you find out which is the best option for you, here's our expert guide to both treatments.

Article Summary

• Tadalafil and sildenafil are both popular treatments for erectile dysfunction (ED). Tadalafil is the generic version of Cialis, and sildenafil is the generic version of Viagra.
• Because tadalafil and sildenafil are both PDE5 inhibitors, they work in the same way to support sexual function by increasing blood flow to your penis. Neither medication affects sexual desire, but they can help you achieve and maintain a stronger, longer-lasting erection once aroused.
• Both oral ED medications have high success rates and share similar side effects. The main difference between tadalafil and sildenafil is how they are dosed and how long their effects last.

What is tadalafil?

Tadalafil is the active ingredient of the drug Cialis and comes as a generic medication also called Tadalafil. This means they contain the same active ingredient (tadalafil), but are prescribed under different names. The main difference between tadalafil and Cialis is cost, with branded Cialis often being more expensive than generic tadalafil. [1]

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 experience sexual stimulation. On-demand doses of tadalafil have the same effect, but they help you get erections for up to a 36-hour period, and you don't need to take them every day.

What is sildenafil?

Sildenafil is the generic version of Viagra, the best-known treatment for erectile dysfunction. Like tadalafil and Cialis, sildenafil and Viagra both contain the same active ingredient (sildenafil citrate) but are prescribed under different names. [2]

And, aside from cosmetic differences (Viagra is known for its iconic 'little blue pill' appearance, while sildenafil is produced as white tablets), cost is the biggest difference between Viagra and generic sildenafil. So, if sildenafil is an appropriate treatment for you, whether you choose Viagra or the generic version comes down to your preference.

How do erectile dysfunction treatments work?

Both tadalafil and sildenafil belong to the same class of medications, called phosphodiesterase type 5 (PDE5) inhibitors. [3] PDE5 inhibitors 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. This is why they can be an effective treatment for erectile dysfunction. PDE5 inhibitors don't affect your sexual desire, just the physical aspect of erectile dysfunction.

Does tadalafil work faster than sildenafil?

Tadalafil and sildenafil both take roughly within 20-30 minutes for some patients, but tadalafil lasts significantly longer.

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 simply take it in advance for more spontaneous sex.

In contrast, one dose of sildenafil will stay in your body for up to 4-5 hours.

Is sildenafil more effective than tadalafil?

Both medications have a high success rate, helping the majority of men to regain control over erectile dysfunction. 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. [4] Both sildenafil and tadalafil are effective treatments for erectile dysfunction. There is not a clear, universal winner for effectiveness overall, and choice often depends on factors such as onset, duration, side effects, and patient preference.

Does tadalafil have fewer side effects than sildenafil?

Because these drugs work in a similar way (with different active ingredients), they share many of the same common side effects. [5] These include: headaches, stuffy nose, facial flushing and indigestion.

In most cases, these side effects are usually mild. Seek urgent medical attention by calling 999 or attending A&E immediately if you experience any of these severe side effects while taking tadalafil or sildenafil:

• Chest pain
• Sudden loss of vision
• A prolonged, painful erection lasting over 4 hours (priapism)
• Severe allergic reaction (anaphylaxis). Signs include difficulty breathing or swelling of the lips, mouth, tongue or throat.

It's always best to monitor any side effects, and speak to your clinical team if you have any concerns. [6]

Can you make lifestyle changes to help with ED?

Yes. You can make some small changes to your lifestyle that can have an overall impact on your experience with erectile dysfunction. ED is closely linked to vascular health, and that's why making simple adjustments to your lifestyle like increasing your physical exercise, quitting smoking and reducing alcohol intake could help minimize any health risks. [7]

Choosing a treatment

Both treatments are established as effective for improving your blood circulation to help you get harder erections during sexual activity. They also have very similar common side effects.

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

If you prefer, chewable tablets could be a good alternative to traditional capsules because they're typically more discreet, easier to swallow and sometimes flavored. They also contain the same active ingredients as other ED medications.

Remember that erectile dysfunction treatments always need to be prescribed by a medical professional, and used in line with guidance from your clinical team.

Find out what treatment is suitable for you with MedExpress.

Note from the experts: This blog shouldn't be regarded as medical advice, diagnosis, or treatment. We make sure everything we publish is fact checked by clinical experts and regularly reviewed, but it may not always reflect the most recent health guidelines. Always speak to your doctor about any health concerns you have.

References

1. Carrier S, Brock GB, Pommerville PJ, Shin J, Anglin G, Whitaker S, et al. Efficacy and safety of oral tadalafil in the treatment of men in Canada with erectile dysfunction: a randomized, double-blind, parallel, placebo-controlled clinical trial. The journal of sexual medicine [Internet]. 2005 Sept;2(5):685–98. Available from: https://pubmed.ncbi.nlm.nih.gov/16422827/
2. Sildenafil (Oral Route) Description and Brand Names - Mayo Clinic [Internet]. www.mayoclinic.org. Available from: https://www.mayoclinic.org/drugs-supplements/sildenafil-oral-route/description/drg-20066989
3. Mills TM. Vasoconstriction and vasodilation in erectile physiology. Current Urology Reports. 2002 Nov;3(6):477–83.
4. Steers W, Guay A, Leriche A, Gingell C, Hargreave T, Wright P, et al. Assessment of the efficacy and safety of Viagra® (sildenafil citrate) in men with erectile dysfunction during long-term treatment. International Journal of Impotence Research. 2001 Oct 1;13(5):261–7.
5. Tadalafil (CIALIS) vs Sildenafil (Viagra) – Is One Better? [Internet]. Dcurology.net. 2025. Available from: https://dcurology.net/2023/06/07/comparing-tadalafil-generic-cialis-and-sildenafil-generic-viagra/
6. Gong B, Ma M, Xie W, Yang X, Huang Y, Sun T, et al. Direct comparison of tadalafil with sildenafil for the treatment of erectile dysfunction: a systematic review and meta-analysis. International Urology and Nephrology. 2017 July 24;49(10):1731–40.
7. Maiorino MI, Bellastella G, Esposito K. Lifestyle modifications and erectile dysfunction: what can be expected? Asian Journal of Andrology [Internet]. 2015;17(1):5–10. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291878/