Viagra vs. Tadalafil

See how Viagra and Tadalafil compare on approved uses, dosing, side effects, and cost.

Key Takeaways

  • Viagra and tadalafil are both PDE5 inhibitors that treat erectile dysfunction by improving blood flow, but they differ in how long they last and how they're dosed.

  • Viagra is taken as needed before sex, while tadalafil can be taken as needed or as a lower daily dose that stays effective for up to 36 hours.

  • Tadalafil is also FDA-approved for benign prostatic hyperplasia and pulmonary arterial hypertension, while Viagra is approved only for erectile dysfunction.

Viagra vs. Tadalafil Drug Summary

Viagra

Viagra (sildenafil citrate) is a PDE5 inhibitor that treats erectile dysfunction by relaxing blood vessels to improve blood flow to the penis. It is taken as an oral tablet as needed, roughly 30 to 60 minutes before sexual activity. Viagra was the first PDE5 inhibitor approved for ED, back in 1998.

Tadalafil

Tadalafil is a PDE5 inhibitor that treats erectile dysfunction the same way, by improving blood flow to the penis. It is taken as an oral tablet either as needed before sex or as a lower daily dose, and its effects can last up to 36 hours. Tadalafil is also FDA-approved to treat benign prostatic hyperplasia and pulmonary arterial hypertension.

Viagra vs. Tadalafil Side Effects

Viagra

Most common
headache (up to 28%)
dyspepsia (up to 17%)
flushing (up to 19%)
abnormal vision (up to 11%)

Tadalafil

Most common
headache (up to 15%)
dyspepsia (up to 10%)
back pain (up to 6%)
myalgia (up to 3%)

Viagra vs. Tadalafil Dosage

Viagra

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

Viagra vs. Tadalafil Indications

Viagra

Viagra is FDA-approved only for treating erectile dysfunction in adult men. It does not carry approval for any other condition.

  • Treats erectile dysfunction in adult men

  • Taken as needed before sexual activity

  • Not approved for use in women

  • Not approved for children

Tadalafil

Tadalafil is FDA-approved for erectile dysfunction, for symptoms of benign prostatic hyperplasia, for both conditions together, and for pulmonary arterial hypertension to improve exercise ability.

  • Treats erectile dysfunction

  • Treats symptoms of BPH

  • Treats combined ED and BPH

  • Improves exercise ability in pulmonary arterial hypertension

Viagra vs. Tadalafil Pros and Cons

Viagra

Viagra has decades of real-world use as the original oral ED treatment and offers simple as-needed dosing with three fixed strengths. Its label carries no boxed warning, though its window of effectiveness is shorter than tadalafil's.

Pros

  • First PDE5 inhibitor approved, longest real-world track record

  • Simple dosing with only three strengths to choose from

  • No boxed warning on the FDA label

  • No daily pill to manage if used only occasionally

Cons

  • Must be timed around sexual activity each time

  • Shorter window of effectiveness than tadalafil

  • Not approved for BPH or pulmonary arterial hypertension

  • Higher rates of flushing and vision changes reported in trials

Tadalafil

Tadalafil offers more flexibility with both as-needed and daily dosing options, plus a much longer window of effectiveness per dose. It also carries added FDA approvals for BPH and pulmonary arterial hypertension, though its label lists specific warnings about vision and hearing loss.

Pros

  • Can be taken daily instead of timed around sex

  • Effective for up to 36 hours per dose

  • Also FDA-approved for BPH and pulmonary arterial hypertension

  • Lower rates of headache and dyspepsia reported in trials

Cons

  • More dosing options can make choosing a regimen harder

  • Label specifically warns of sudden vision or hearing loss

  • Explicit priapism warning on the label

  • Needs caution when combined with alpha-blockers

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