There are four FDA-approved PDE5 inhibitors for ED, but three dominate the conversation: Stendra (avanafil), Viagra (sildenafil), and Cialis (tadalafil). Each has a distinct strength. Stendra is the fastest. Cialis lasts the longest. Viagra is the most affordable. The question is which one fits your life.
The Head-to-Head Comparison
| Factor | Stendra (Avanafil) | Viagra (Sildenafil) | Cialis (Tadalafil) |
|---|---|---|---|
| Onset | 15–30 min | 30–60 min | 30–60 min |
| Duration | 4–6 hrs | 4–6 hrs | Up to 36 hrs |
| Food impact | Minimal | Delayed by fatty meals | Minimal |
| Daily option | No | No | Yes (5mg daily) |
| Generic available | Yes (2024) | Yes (2017) | Yes (2018) |
| Generic cost/pill | $10–$23 | $0.30–$3 | $0.30–$2 |
| FDA approved | 2012 | 1998 | 2003 |
Speed: Stendra’s Defining Advantage
Avanafil is the most selective PDE5 inhibitor, meaning it targets the specific enzyme in erectile tissue with less activity on other PDE enzymes.[5] This selectivity contributes to its faster onset—some men report effects in as little as 15 minutes, compared to 30–60 minutes for sildenafil and tadalafil.
For men who value spontaneity and don’t want to plan an hour ahead, that 15-minute window is the primary reason to choose Stendra.
Duration: Cialis’s Clear Win
Tadalafil’s 36-hour window is unmatched. You can take it Friday evening and still experience effects Sunday morning. This has earned it the nickname “the weekend pill.”
Tadalafil is also the only PDE5 inhibitor approved for once-daily dosing at 5mg, which maintains a constant level in your system so you don’t need to time your dose around sexual activity at all.
Side Effects: Stendra Wins on Tolerability
All PDE5 inhibitors share similar potential side effects: headache, flushing, nasal congestion, and back pain. However, clinical trials suggest avanafil may produce fewer side effects due to its higher selectivity for PDE5.[1]
Sildenafil is the most likely to cause visual disturbances (the “blue tinge” effect) because it also inhibits PDE6, which is found in the retina. Avanafil has minimal PDE6 activity.[5]
Food and Alcohol Interactions
Sildenafil is notably affected by food—a high-fat meal can delay absorption by up to an hour and reduce peak blood levels.[3] Avanafil and tadalafil are far less affected, making them better choices if you plan to take your medication with dinner.
Cost: Sildenafil and Tadalafil Dominate
This is where the conversation shifts dramatically. Generic sildenafil costs as little as $0.30 per pill through some online providers, and generic tadalafil is similarly affordable.[6] Generic avanafil starts at roughly $10 per pill—better than brand Stendra, but still 10–30x more expensive than the alternatives.
Find the best price on generic ED medications from vetted online providers.
Compare Providers →So Which One Should You Choose?
Choose Stendra if: Speed is your top priority and cost is secondary. You want the fastest onset with the fewest food restrictions.
Choose Viagra (sildenafil) if: You want the most affordable option with the longest clinical track record. Take it on an empty stomach for best results.
Choose Cialis (tadalafil) if: You want the longest duration, or you prefer a daily low-dose pill that eliminates the need to time doses. Best for men in regular sexual relationships.
The Bottom Line
All three medications work through the same mechanism—they block PDE5 to increase blood flow. The differences are speed, duration, and cost. For most men, starting with generic sildenafil or tadalafil makes sense because the cost difference is dramatic. If those don’t work well or you specifically need faster onset, generic avanafil is now a viable option at a fraction of what Stendra used to cost.