Short answer: Stendra (avanafil) and Viagra (sildenafil) are both PDE5 inhibitor tablets for erectile dysfunction, taken as needed, at most once a day.12 The Stendra label says it can be taken as early as about 15 minutes before sex at 100 mg or 200 mg; Viagra's usual dose is 50 mg about 1 hour before. Neither label reports a trial against the other.
| Stendra (avanafil) | Viagra (sildenafil) | |
|---|---|---|
| Tablet strengths | 50, 100 or 200 mg1 | 25, 50 or 100 mg2 |
| Usual start | 100 mg as early as about 15 minutes before sex1 | 50 mg about 1 hour before sex (30 minutes to 4 hours)2 |
| Dose range | 50 mg (about 30 minutes before) to 200 mg (about 15 minutes before)1 | 25 mg to 100 mg2 |
| How often | At most once a day1 | At most once a day2 |
| Food | With or without food; a high-fat meal delayed the peak about 1.1 to 1.25 hours1 | With or without food; may take a little longer after a high-fat meal2 |
| Headache | 5.1% to 10.5% vs 1.7% on placebo1 | 16% to 28% vs 7% on placebo (fixed-dose trials)2 |
| Flushing | 3.2% to 4.3% vs 0.0%1 | 10% to 19% vs 2%2 |
| Vision changes | 1 man across all trials reported a color vision change1 | Abnormal vision, mostly a color tinge, up to 11% on 100 mg vs 1%2 |
| With nitrates or riociguat | Not to be used1 | Not to be used2 |
The labels give different timing. Stendra may be taken as early as about 15 minutes before sex at 100 mg or 200 mg, or about 30 minutes before at 50 mg; peak levels came at a median 30 to 45 minutes when fasting.1 Viagra is usually taken about 1 hour before, and may be taken anywhere from 30 minutes to 4 hours before.2 The labels do not include a trial comparing how fast the two work.
Stendra's three 3-month trials reported headache in 5.1% to 10.5% across doses vs 1.7% on placebo, and flushing in 3.2% to 4.3% vs none.1 Viagra's fixed-dose trials reported headache in 16% to 28% vs 7%, flushing in 10% to 19% vs 2%, and indigestion in 3% to 17% vs 2%.2 These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison. Placebo rates also differed between the programs.
Both labels share warnings: no nitrates or riociguat, care with alpha-blockers and blood pressure medicines, prolonged erections, and rare sudden vision or hearing loss.12
Which tablet and dose to use is a question for your prescriber, especially with heart disease or other medicines. More detail: Stendra side effects, Viagra side effects, the Stendra and Viagra dosing schedules, and the Sildenafil guide.