Sildenafil vs tadalafil: which is better?
Quick answer
Neither is objectively better -- they're clinically equivalent in efficacy. The key difference is duration: sildenafil lasts 4-6 hours (plan ahead), tadalafil lasts up to 36 hours or can be taken daily (spontaneous). Your choice depends on how often you need it, whether spontaneity matters, and which side effect profile you tolerate better.
Efficacy comparison
Both sildenafil and tadalafil improve erectile function in roughly 70-80% of men with ED. Clinical trials show similar response rates when dosed appropriately. Neither has proven superiority in head-to-head studies for the primary outcome of successful intercourse.
The IIEF (International Index of Erectile Function) score improvements are comparable: sildenafil 50-100mg and tadalafil 10-20mg on-demand produce similar mean improvements. If one doesn't work, switching to the other succeeds in about 50% of non-responders, suggesting some men have individual pharmacological preferences.
Duration and timing
Sildenafil: onset 30-60 minutes. Duration 4-6 hours. Must be taken on an empty stomach or a light meal for reliable absorption (fatty meals delay it significantly). Best for planned encounters.
Tadalafil: onset 30-120 minutes. Duration up to 36 hours. Not affected by food. Available as daily dosing (2.5-5mg) for continuous coverage. Best for spontaneity.
This is usually the deciding factor. Men who want to take a pill and have a wide window of opportunity prefer tadalafil. Men who want a stronger peak effect for a specific encounter sometimes prefer sildenafil. The 36-hour window of tadalafil is its strongest differentiator.
Side effect differences
Sildenafil is more likely to cause: visual disturbances (blue tint, light sensitivity) due to cross-reactivity with PDE6 in the retina, facial flushing, and nasal congestion. These effects are dose-related and more common at 100mg.
Tadalafil is more likely to cause: back pain and muscle aches (reported by 5-6% of patients, usually starting 12-24 hours after dosing and lasting 1-2 days). This is thought to result from PDE11 inhibition in skeletal muscle.
Both cause headaches at similar rates. Both can cause indigestion. Overall tolerability is comparable, but the specific side effect profile may make one more comfortable for a given patient.
Cost comparison
Both are available as generics, making them significantly cheaper than brand names. Generic sildenafil is often slightly cheaper per pill than generic tadalafil, but per-sexual-encounter costs vary based on your frequency.
Daily tadalafil at 5mg means 30 pills per month regardless of sexual frequency. On-demand sildenafil at 2-4 pills per month may be cheaper for men who are less frequently active. Through LYV, both are available as part of prescribed ED protocols at competitive pricing.
Learn more about Sildenafil + Tadalafil
Frequently asked questions
Can I try both sildenafil and tadalafil to see which I prefer?
Yes. Many prescribers will prescribe both so you can compare. Try each at least 3-4 times before deciding (first-time use doesn't always reflect the drug's true effect due to anxiety). Never take both on the same day. Give at least 24-48 hours between switching.
Which has fewer side effects?
Neither consistently wins. Sildenafil causes more visual changes and flushing. Tadalafil causes more back pain and muscle aches. Headache rates are similar. The "better" option is whichever produces side effects you find more tolerable. Many men tolerate both equally well.
Is there a third option beyond sildenafil and tadalafil?
Vardenafil (Levitra) and avanafil (Stendra) are two other FDA-approved PDE5 inhibitors. Avanafil has the fastest onset (15-30 minutes) and fewest side effects but shorter duration. Vardenafil is similar to sildenafil in profile. If neither sildenafil nor tadalafil works well, these alternatives are worth discussing.
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