The short verdict
Avanafil suits men who want less planning: a dose that can work in roughly 15 minutes, with no need to time it around meals, and a lower chance of the blue-tinted vision some men get on sildenafil. Sildenafil suits men who want the most familiar option at the lowest price, and who do not mind taking a tablet about an hour ahead. Both are FDA-approved PDE5 inhibitors that work the same way, and neither has been shown to be stronger than the other. For many men, cost and what their pharmacy can supply end up deciding.
Side by side
| Sildenafil (Viagra) | Avanafil (Stendra) | |
|---|---|---|
| First U.S. approval | 1998 | 2012 |
| Label timing | About 1 hour before sex, range 30 minutes to 4 hours | As early as about 15 minutes before (100 or 200 mg); about 30 minutes for 50 mg |
| Typical duration (AUA table) | Up to 12 hours | Up to 6 hours |
| Food | High-fat meal can slow it | Taken with or without food |
| PDE5 selectivity over the retinal enzyme PDE6 | About 10-fold | More than 100-fold |
| Common side effects | Headache, flushing, indigestion, abnormal vision, nasal congestion | Headache, flushing, nasal congestion, sore throat and nose, back pain |
| Generic | Yes, widely stocked | Newer to the generic market |
| Use with nitrates | Never | Never |
How each one works
Both drugs block PDE5, the enzyme that switches off the blood-flow signal in the penis. With that brake removed, the arteries relax more fully during arousal and the erection is firmer and easier to keep. Neither drug causes an erection by itself, and both need sexual stimulation.
Where they differ is speed and focus. The Stendra label allows the 100 mg and 200 mg doses to be taken as early as about 15 minutes before sex, and it can be taken with or without food. MedlinePlus gives the same timing and adds the once-per-day limit. Sildenafil reaches its useful level more slowly and, per the Viagra label, is usually taken about an hour ahead. Our avanafil and sildenafil pages cover each drug in more detail.
Why vision side effects differ
Your retina uses a close cousin of PDE5, called PDE6, to process light. A drug that blocks PDE6 a little can briefly tint vision blue or make blues and greens harder to tell apart. The Viagra label explains that sildenafil is only about 10 times more potent at PDE5 than PDE6, and it lists abnormal vision among its most common side effects. The Stendra label puts avanafil’s preference for PDE5 at more than 100-fold, and vision changes are not among its most common effects.
The American Urological Association’s ED guideline agrees that sildenafil tended to have the highest rates of visual disturbance among the pills studied, while noting that data for avanafil were more limited. Sudden loss of vision in one or both eyes is different: it is a rare emergency warned about on every PDE5 label, and it means stopping the drug and getting care right away.
Other side effects and safety
Headache, flushing and a stuffy nose are common to both, because PDE5 also sits in blood vessels outside the penis. Most are mild and fade as the dose wears off.
The safety rules overlap, with a few differences in the details:
- Nitrates. Both are off-limits with nitroglycerin or other nitrate medicines. The Stendra label says at least 12 hours should pass after avanafil before a nitrate is given in an emergency, and only under medical supervision.
- Alpha-blockers. Men on doxazosin, tamsulosin and similar drugs need to be stable on them first, then start at the lowest dose: 25 mg for sildenafil and 50 mg for avanafil, per the labels.
- Interacting drugs. Strong CYP3A4 blockers, such as certain antifungals, HIV medicines and some antibiotics, rule out avanafil and lower the sildenafil dose.
Call 911 for an erection lasting longer than 4 hours, chest pain during sex, or sudden vision or hearing loss.
Convenience and cost: what usually decides
Speed sounds like a clear win for avanafil, and for spontaneous sex it can be. But the AUA guideline notes that 56% to 81% of pill failures come from using the medicine incorrectly, such as taking it with a large meal or without stimulation. A man who learns to time sildenafil well may get most of the benefit he hoped for from avanafil. Our guide to taking sildenafil and tadalafil covers the timing details.
Price is the other lever. Sildenafil has been sold as a generic for years and is stocked almost everywhere; our page on generic sildenafil versus Viagra explains why the generic is the same drug. Avanafil is newer, fewer pharmacies keep it on hand, and its price per tablet is usually higher. Exact costs change with the pharmacy, the strength and the quantity, so compare like for like. The ED medication cost guide explains what moves the number.
If you need a long window rather than a fast start, neither may be ideal. Tadalafil lasts much longer, and our tadalafil versus vardenafil comparison shows how the longer-acting options stack up.
How Ultimate Male helps you choose
Choosing between these two depends on facts specific to you: what you take for blood pressure, the prostate or infections, how you have responded to any PDE5 pill before, how much planning your sex life allows, and what each option will cost you. At a private consultation in San Gabriel or Downey, your provider reviews those points, checks your blood pressure and, when labs are due, draws them on site the same day.
Ask directly which PDE5 medicines the clinic can supply for you right now and what each would cost within your plan, since availability and pricing for avanafil can change. You get a quote before you commit, and you can pay with an HSA or FSA card where your plan allows, or through CareCredit, Prosper Healthcare Lending or Afterpay. See every pill, topical and injectable option on our ED medications page.
