How long does Viagra last?
The Viagra label does not print how long an erection lasts. It says sildenafil peaks 30 to 120 minutes after a dose (median 60), has a half-life of about 4 hours, and may be taken 30 minutes to 4 hours before sex. A high-fat meal slows it. Mendoxa's 3-in-1 tablet starts at $129.
Start your ED visit From $129/month. If prescribed · Cancel anytime · Available in 49 states (not California).
Viagra timing on the label
| Question | What the Viagra label says |
|---|---|
| How long to kick in? | Peak plasma level 30 to 120 minutes after a dose (median 60 minutes), fasted |
| When to take it | About 1 hour before sex; anywhere from 30 minutes to 4 hours before |
| After a high-fat meal | Peak delayed by about 60 minutes on average; peak level 29% lower |
| Half-life | About 4 hours (sildenafil and its active metabolite) |
| After 24 hours | Plasma levels “much lower than at peak concentration” |
| How often | Once per day at most |
How does Viagra work?
The label explains that an erection starts when sexual stimulation releases nitric oxide in the penis. Sildenafil blocks PDE5, the enzyme that breaks down cGMP, so the nitric oxide signal lasts. It has no effect without sexual stimulation.
Mendoxa ED plans and prices
The Mendoxa ED tablet is a compounded rapid-dissolve tablet with sildenafil (the active ingredient in Viagra), tadalafil (the active ingredient in Cialis) and apomorphine. It dissolves under the tongue. The Mendoxa ED page lists a maximum of 1 dose per 24 hours. A licensed clinician decides if it fits you and selects the strength. Compounded medicines are not FDA-approved.
| Plan | 1-month plan | Per tablet | 3-month plan | Per tablet (3 months) |
|---|---|---|---|---|
| 6 tablets / month | $129 | $21.50 | $329 | $18.28 |
| 10 tablets / month | $149 | $14.90 | $379 | $12.63 |
| 20 tablets / month | $179 | $8.95 | $449 | $7.48 |
If prescribed · Cancel anytime · Available in 49 states (not California). Prices from the Mendoxa intake at try.mendoxa.co/f/ed on Oct 17, 2026. The intake always shows the current price.
Does Viagra make you last longer?
The Viagra label is about getting and keeping an erection firm enough for sex. It does not claim to delay ejaculation. Abnormal ejaculation is listed only among less common reported events.
How long does Viagra stay in your system?
With a half-life of about 4 hours, levels fall by half roughly every 4 hours. The label says levels at 24 hours are much lower than at peak, but that it is unknown when a nitrate can be given safely after Viagra. If you might need nitroglycerin, tell the clinician first.
The Viagra and Cialis labels list the same hard stops. Do not use them with organic nitrates in any form, or with a guanylate cyclase stimulator such as riociguat. Do not use them if sex is inadvisable because of your heart. Get emergency care for an erection that lasts more than 4 hours. Stop and get care for a sudden loss of vision in one or both eyes, or a sudden decrease or loss of hearing.
Side effects
Most common side effects (2% or more) on the Viagra label: headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash. On the Cialis label: headache, dyspepsia, back pain, myalgia, nasal congestion, flushing and pain in limb.
FAQ
How long does Viagra last?
The label does not give an erection duration. Sildenafil's half-life is about 4 hours, and it may be taken 30 minutes to 4 hours before sex.
How long does it take Viagra to work?
Peak blood levels come 30 to 120 minutes after a dose, with a median of 60 minutes. The label says take it about 1 hour before sex.
Does food change how fast Viagra works?
Yes. A high-fat meal delayed the peak by about 60 minutes and lowered it by 29% on the label.
How long does sildenafil stay in your system?
Its half-life is about 4 hours. By 24 hours levels are much lower than at peak, but the label does not say when nitrates become safe.
Is there a longer-lasting option?
Tadalafil (Cialis) reports effect up to 36 hours. Mendoxa's compounded tablet combines sildenafil and tadalafil with apomorphine, from $129 a month, if prescribed.
Start your ED visit: plans and prices
The Mendoxa ED tablet is a compounded rapid-dissolve tablet with sildenafil (the active ingredient in Viagra), tadalafil (the active ingredient in Cialis) and apomorphine. It dissolves under the tongue. The Mendoxa ED page lists a maximum of 1 dose per 24 hours. A licensed clinician decides if it fits you and selects the strength. Compounded medicines are not FDA-approved.
| Plan | 1-month plan | Per tablet | 3-month plan | Per tablet (3 months) |
|---|---|---|---|---|
| 6 tablets / month | $129 | $21.50 | $329 | $18.28 |
| 10 tablets / month | $149 | $14.90 | $379 | $12.63 |
| 20 tablets / month | $179 | $8.95 | $449 | $7.48 |
If prescribed · Cancel anytime · Available in 49 states (not California). Prices from the Mendoxa intake at try.mendoxa.co/f/ed on Oct 17, 2026. The intake always shows the current price.
References
- DailyMed: VIAGRA (sildenafil citrate) tablet, film coated, label revised 12/2017. Accessed Oct 17, 2026.
- FDA (Drugs@FDA): VIAGRA prescribing information, NDA 020895. Accessed Oct 17, 2026.
- DailyMed: CIALIS (tadalafil) tablet, film coated, label revised 3/2026. Accessed Oct 17, 2026.
- Mendoxa ED care (product, format, max 1 dose per 24 hours). Accessed Oct 17, 2026.
- Mendoxa ED intake: plan prices (term_options). Accessed Oct 17, 2026.
About Mendoxa
Mendoxa (mendoxa.co) is a US telehealth brand. Licensed clinicians in the LocumTele network review each online visit, and prescriptions are filled by Rush Pharmacy, a licensed US pharmacy. Available in 49 states (not California).
- A licensed clinician reviews every visit and can say no. A prescription is not automatic.
- A compounded medicine is not an FDA-approved finished product.
- Plans: 1 month or 3 months, from $129. If prescribed · Cancel anytime · Available in 49 states (not California).
Compounded medication prescribed only if a licensed U.S. clinician decides it is appropriate. Not FDA-approved as a finished product. Not available in California. This site is not for emergencies. Call 911 if you need urgent care.