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

Most common
Headache (up to 16%)
Dyspepsia (up to 7%)
Nasal congestion (up to 4%)
Flushing (up to 10%)

Tadalafil

Most common
Headache (up to 15%)
Dyspepsia (up to 10%)
Nasal congestion (up to 3%)
Back pain (up to 6%)

Sildenafil vs. Tadalafil Dosage

Sildenafil

Dosage
Dosage Table
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

Dosage
Dosage Table
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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