How Long Does Viagra Take to Work?
Viagra (sildenafil) usually starts working 30 to 60 minutes after you take it. The label says to take it about an hour before sex, and it can be taken anywhere from 30 minutes to 4 hours before. It needs sexual arousal to work: it makes an erection easier to get and keep, but it doesn't create one on its own.
The timeline after a dose
| Time after the pill | What's happening |
|---|---|
| 0–30 minutes | Absorbing. Some men notice an effect this early, most don't. |
| 30–60 minutes | Typical onset. On an empty stomach, blood levels peak around the 1-hour mark. |
| 1–4 hours | The labeled window for sex. Arousal leads to an erection more easily. |
| After about 4 hours | Levels have roughly halved (its half-life is about 4 hours) and the effect fades. |
The label allows one dose a day. Don't take a second pill if the first seems slow.
What makes it slower or weaker
- A heavy meal. A high-fat meal delays sildenafil's peak by about an hour and lowers it by roughly 29%. Take it on an empty stomach or after something light.
- Alcohol. A drink or two is usually fine, but heavy drinking makes erections harder on its own and adds to the blood-pressure drop sildenafil can cause.
- The wrong expectations. Without arousal, nothing much happens. That's normal and not a sign the pill failed.
- Dose. The usual starting dose is 50 mg, with a range of 25 to 100 mg. A prescriber may start at 25 mg for men over 65, men with liver or severe kidney problems, or men taking drugs that raise sildenafil levels.
How it compares with the other ED pills
| Take before sex | Effect window | Food | |
|---|---|---|---|
| Sildenafil (Viagra) | About 1 hour | Up to about 4 hours | High-fat meal delays it |
| Vardenafil (Levitra) | About 1 hour | Several hours | High-fat meal weakens it |
| Avanafil (Stendra) | About 15 minutes (100–200 mg) | Several hours | High-fat meal delays it |
| Tadalafil (Cialis) | Any time up to 36 hours | Up to 36 hours, or daily low dose | No effect |
If planning around a 1-hour window doesn't suit you, tadalafil is the usual alternative: one dose covers a weekend, or a low daily dose removes the timing question altogether. Our ED pills comparison covers doses and side effects for all four.
If it doesn't work
Most guidance suggests giving sildenafil several tries before deciding it doesn't work. Before then, check:
- Timing. Did you wait at least 30 to 60 minutes?
- Food. Was it taken after a big or fatty meal?
- Dose. Some men need 100 mg; others get side effects at 50 mg and do better on a lower dose or a different drug.
- Something else going on. ED can be an early sign of heart disease, diabetes or low testosterone. A clinician can check for these, which is part of why ED pills need a prescription.
If an erection lasts more than 4 hours, get emergency care.
Who shouldn't take it
Never combine sildenafil with nitrates (nitroglycerin, isosorbide) or riociguat: together they can drop blood pressure to dangerous levels. Men on alpha-blockers or certain HIV and antifungal drugs need a lower dose. Tell the prescriber everything you take, including supplements.
What generic sildenafil costs through telehealth
Generic sildenafil is one of the cheapest prescriptions online. Live from our price database:
Sildenafil pricing today
Live from our price database and updated by our own price checks. These are today’s prices, not the prices on the date of this article.
| Brand | Plan | Price/mo | Included |
|---|---|---|---|
 LifeMD | Sildenafil (via Rex MD) | $14–$38 | Consults · Shipping |
| Hims & Hers | Sildenafil (generic Viagra) | $16–$44 | Consults · Shipping |
| GoodRx | ED Subscription | $18–$109 | Consults · Shipping |
| Viking Man | Generic Sildenafil | $20–$60 | Shipping |
| MyDrHank | Generic Sildenafil | $25–$35 | Consults · Shipping |
 TelyRx | Generic Sildenafil | $27.99 | — |
 Strut Health | Sildenafil | $29–$59 | Consults · Shipping |
 Ro | Sildenafil | $32–$80 | Consults · Shipping |
Prices shown are based on our most recent research and may not reflect current pricing. Telehealth providers update their pricing frequently. Always verify pricing directly with the provider before purchasing.
See every provider we track on the sildenafil page.
Frequently Asked Questions
How long does Viagra take to work?
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Usually 30 to 60 minutes. The label says to take it about an hour before sex, and it can be taken anywhere from 30 minutes to 4 hours before. It only works with sexual stimulation; it doesn't cause an erection on its own.
How long does Viagra last?
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Its half-life is about 4 hours, and it's labeled for sex up to 4 hours after a dose. It doesn't keep you erect for that whole window: it makes an erection easier to get and keep when you're aroused, and the erection goes down normally after sex.
Does food make Viagra slower?
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Yes. A high-fat meal delays sildenafil's peak by about an hour and lowers it by roughly 29%, according to the label. Taking it on an empty stomach or after a light meal works fastest.
What if Viagra doesn't work the first time?
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Many men need a few tries. Check the timing, skip a heavy meal beforehand, and make sure there's arousal. If it still doesn't work after several attempts, a clinician may adjust the dose or switch you to tadalafil, which has a longer window and isn't affected by food.
Which ED pill works fastest?
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Avanafil (Stendra) is labeled to work as early as about 15 minutes at 100 or 200 mg. Sildenafil and vardenafil are labeled for about an hour before sex. Tadalafil can be taken any time up to 36 hours before.
Can I take Viagra twice in one day?
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No. The label limits sildenafil to one dose a day. If one dose isn't enough, talk to your prescriber about a different dose or medication rather than doubling up.
When is an erection an emergency?
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If an erection lasts more than 4 hours, get emergency care. Prolonged erections (priapism) can permanently damage the penis if not treated quickly.
Sources
Medical disclaimer:This guide is for general information and isn't medical advice. Talk to a licensed clinician about your own situation before starting, stopping or changing any treatment.