Sildenafil vs. Tadalafil
See how Sildenafil and Tadalafil compare on approved uses, dosing, side effects, and cost.
Key Takeaways
Sildenafil and tadalafil are both PDE5 inhibitors for erectile dysfunction, but tadalafil lasts up to 36 hours while sildenafil works for about 4 to 6 hours.
Tadalafil is also FDA-approved for benign prostatic hyperplasia, while sildenafil's approved use beyond ED is limited to pulmonary arterial hypertension.
Both drugs carry similar core risks, including nitrate interactions, priapism, and rare vision or hearing loss, so timing and lifestyle often drive the choice.
Sildenafil vs. Tadalafil Drug Summary
Sildenafil
Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor taken as an oral tablet to treat erectile dysfunction, used on an as-needed basis about 30 to 60 minutes before sexual activity. It's also approved under the brand name Revatio for pulmonary arterial hypertension. Its effects typically last about 4 to 6 hours.
Tadalafil
Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor available as an oral tablet, approved for erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. It can be taken as needed before sexual activity or as a low daily dose. Its effects can last up to 36 hours.
Sildenafil vs. Tadalafil Side Effects
Sildenafil
Tadalafil
Sildenafil vs. Tadalafil Dosage
Sildenafil
Tadalafil
| STAGE | DOSE | WHEN |
| Starting dose | 25 mg as needed | At the start |
| Maximum dose | 25 mg as needed | Same as starting |
| Dose changes | None | Fixed dose |
| STAGE | DOSE | WHEN |
| Starting dose | 20 mg once daily | Weeks 1-4 |
| Maximum dose | 20 mg once daily | Same as starting |
| Dose changes | None | Fixed dose |
Sildenafil
| STAGE | DOSE | WHEN |
| Starting dose | 25 mg as needed | At the start |
| Maximum dose | 25 mg as needed | Same as starting |
| Dose changes | None | Fixed dose |
Tadalafil
| STAGE | DOSE | WHEN |
| Starting dose | 20 mg once daily | Weeks 1-4 |
| Maximum dose | 20 mg once daily | Same as starting |
| Dose changes | None | Fixed dose |
Sildenafil vs. Tadalafil Indications
Sildenafil
Sildenafil is FDA-approved to treat erectile dysfunction and, under the brand name Revatio, pulmonary arterial hypertension. Some doctors also prescribe it off-label for conditions like Raynaud's phenomenon or female sexual arousal disorder, though these uses aren't FDA-approved.
Erectile dysfunction (FDA-approved)
Pulmonary arterial hypertension, as Revatio (FDA-approved)
Raynaud's phenomenon (off-label)
Female sexual arousal disorder (off-label)
Tadalafil
Tadalafil is FDA-approved for erectile dysfunction, benign prostatic hyperplasia, and the combination of both conditions in men who have them together. It's also approved to improve exercise ability in pulmonary arterial hypertension. It has no widely recognized off-label uses beyond these indications.
Erectile dysfunction (FDA-approved)
Benign prostatic hyperplasia (FDA-approved)
Combined ED and BPH (FDA-approved)
Pulmonary arterial hypertension (FDA-approved)
Sildenafil vs. Tadalafil Pros and Cons
Sildenafil
Sildenafil works fast and clears the body within a few hours, making it well suited to planned, single-use dosing. It has been on the market since 1998, giving it the longest track record among PDE5 inhibitors. It is not approved for prostate symptoms, so men with both ED and BPH may need a different option.
Pros
First PDE5 inhibitor approved, with over 25 years of use
Shorter duration means side effects clear faster
Available in three dose strengths for tailored dosing
Effects wear off within about 4 to 6 hours
Cons
Not approved for benign prostatic hyperplasia symptoms
High-fat meals can delay or reduce its effectiveness
Must be timed before each sexual encounter, no daily option
Shorter window than tadalafil limits spontaneity
Tadalafil
Tadalafil's long half-life means one dose can stay effective for up to 36 hours, and a daily low dose removes the need to plan around sex. It's also FDA-approved for benign prostatic hyperplasia, covering both conditions with one medication. Because it lasts longer, any side effects that occur may also last longer.
Pros
Approved for BPH and combined ED-BPH treatment
Effective for up to 36 hours, longest among PDE5 inhibitors
Daily dosing option allows spontaneous activity
Absorption is not significantly affected by food
Cons
Fewer years on the market than sildenafil, since 2003
Multiple dosing regimens can be confusing to manage
Side effects may linger longer given the longer duration
Extra caution needed if also taking alpha-blockers for BPH
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