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Sildenafil vs. tadalafil: which ED medication fits you?
Quick answer
Sildenafil and tadalafil are FDA-approved generic medications that treat erectile dysfunction by improving blood flow.
Sildenafil (the active ingredient in Viagra®) is taken about an hour before sex and works for about 4 hours. Tadalafil (the active ingredient in Cialis®) can work for up to 36 hours and is also available as a low daily dose.
At Surna, sildenafil starts at $49/mo and tadalafil at $49/mo.
Updated · Sources below
Side by side
| Feature | Sildenafil | Tadalafil |
|---|---|---|
| Brand name | Viagra® | Cialis® |
| When to take | About 1 hour before sex | At least 30 minutes before sex, or once daily |
| How long it works | About 4 hours | Up to 36 hours |
| Effect of food | A high-fat meal can slow it down | Not affected by food |
| Daily option | No | Yes, 5 mg daily |
| Also FDA-approved for | — | Urinary symptoms of an enlarged prostate (BPH) |
| Common side effects | Headache, flushing, stuffy nose, upset stomach, vision changes | Headache, indigestion, back pain, muscle aches |
| Surna starting price | $49/mo | $49/mo |
Which is right for you?
Your provider makes the final call based on your health history.
Choose Sildenafil if
- Sex is usually planned a little ahead
- You prefer a shorter-acting medication
- You had back or muscle aches with tadalafil
Choose Tadalafil if
- You want flexibility over a weekend
- You’d rather not plan around a pill (daily)
- You also have urinary symptoms from an enlarged prostate
How they work
Both block PDE5, an enzyme that limits blood flow to the penis, so the body’s natural response to arousal works more easily. Neither creates desire on its own; sexual stimulation is still needed.
Timing and duration
The biggest difference is how long they last. Sildenafil works for about 4 hours, while tadalafil stays active for up to 36 hours. Tadalafil also comes as a low daily dose, so there’s no need to time a pill at all.
Safety for both
Neither medication is safe with nitrates for chest pain or with riociguat, because the combination can cause a dangerous drop in blood pressure. Get emergency care for an erection lasting more than 4 hours or sudden vision or hearing loss.
Questions, answered
Which works faster, sildenafil or tadalafil?
Both can start working in about 30 to 60 minutes. Sildenafil may be slowed by a heavy, high-fat meal; tadalafil isn’t affected by food.
Which lasts longer?
Tadalafil. It can work for up to 36 hours, compared with about 4 hours for sildenafil.
Can I take sildenafil and tadalafil together?
Not on your own. Only combine ED medications if your provider prescribes it, such as a combination tablet designed for that purpose.
Are they the same as Viagra® and Cialis®?
They contain the same active ingredients. Surna dispenses sildenafil and tadalafil as FDA-approved generics, which usually cost much less than the brands.
Sources
- DailyMed. Sildenafil tablets prescribing information. Source
- DailyMed. Tadalafil tablets prescribing information. Source
This page is general information, not medical advice. A licensed provider will determine whether treatment is appropriate for you. Individual results vary. Wegovy®, Ozempic®, and Rybelsus® are registered trademarks of Novo Nordisk; Zepbound® and Mounjaro® of Eli Lilly and Company; Viagra® of Viatris; Cialis® of Eli Lilly and Company. Surna Health is not affiliated with these companies.
Not sure which? Let a provider help.
Answer a few questions and a licensed provider will recommend the option that fits you.
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