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
Tadalafil
Viagra vs. Tadalafil Dosage
Viagra
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 |
Viagra
| 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 |
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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