In short
Overview
Sildenafil or tadalafil: the two most used erection tablets work equally well and differ in timing, duration and food. This page compares them side by side.
Direct Answer
Sildenafil versus tadalafil comes down to timing, because both tablets work equally well. Sildenafil works for about 4 hours and is taken about 1 hour before sex; tadalafil works for up to 36 hours and is also taken as a low daily dose of 5 mg.
Sildenafil (Viagra) and tadalafil (Cialis) are both phosphodiesterase type 5 (PDE5) inhibitors, the first-choice tablets for erectile dysfunction. Neither tablet works without sexual stimulation, and neither is combined with nitrates. Both are prescription-only medicines in Dubai (Dubai Health Authority).
Who This Applies To
- Men with erectile dysfunction choosing their first tablet.
- Men on sildenafil who want more spontaneity.
- Men on tadalafil with back pain or other side effects.
- Men with prostate symptoms as well as erection problems.
Option Comparison / Decision Criteria
How do sildenafil and tadalafil compare?
Sildenafil and tadalafil differ in onset, duration and the effect of food, not in strength. The tables set out the differences.
| Feature | Sildenafil (Viagra) |
|---|---|
| Taken | About 1 hour before sex |
| Works for | About 4 hours |
| Food | A fatty meal delays it |
| Doses | 50 mg, raised to 100 mg |
| Typical side effects | Flushing, headache, indigestion, blue-tinted vision for 2 to 3 hours |
| Feature | Tadalafil (Cialis) |
|---|---|
| Taken | On demand before sex, or 5 mg every day |
| Works for | Up to 36 hours per dose |
| Food | No effect of food |
| Doses | 10 mg, lowered to 5 mg or raised to 20 mg; 5 mg daily |
| Typical side effects | Headache, indigestion, back and muscle pain |
Which works better, sildenafil or tadalafil?
Neither works better: sildenafil, tadalafil, vardenafil and avanafil give similar results in trials. Sildenafil made 57 percent of intercourse attempts successful against 21 percent on placebo in 27 trials with 6,659 men, close to 3 times as often (Archives of Internal Medicine, 2002). Daily tadalafil gave no erectile dysfunction in 50 percent of 268 men against 8 percent on placebo (European Urology, 2006).
Why an In-Person Physician Review Matters
Why does the choice need a doctor?
The choice between sildenafil and tadalafil needs a doctor because the medicines you take decide which tablet is safe and at what dose. Nitrates in any form exclude both tablets. Alpha blockers for the prostate need a stable dose first and a low start. The heart is checked before any erection tablet, because sexual activity is physical exertion and erectile dysfunction often appears before heart disease.
Frequently Asked Questions
No, tadalafil is not stronger than sildenafil. Tadalafil lasts longer, up to 36 hours, while sildenafil lasts about 4 hours; the effect on erections is similar.
No, sildenafil and tadalafil are not combined, because the combination raises the risk of a fall in blood pressure without a better erection.
Tadalafil is the tablet used daily, at 5 mg, and it also treats urinary symptoms from an enlarged prostate.
No, sildenafil and tadalafil improve erections, not desire. Low desire has its own causes and treatment.
Evidence
Where this information comes from
Every figure on this page is taken from the sources below. All of them are free to read, so you can check them yourself.
- Sildenafil for male erectile dysfunction: a systematic review and meta-analysis
- Evaluation of the efficacy and safety of once-a-day dosing of tadalafil 5 mg and 10 mg
- Viagra: European public assessment report
- Cialis: European public assessment report
- Erectile Dysfunction: AUA Guideline
- Drug Control
This page is general medical information and does not replace a personal consultation. Trial results are averages across large groups, not a prediction for any one person.