Works when you are aroused
Sildenafil relaxes the blood vessels in the penis so more blood flows in during sexual stimulation. It supports your natural response, it does not force one.
- 10 doses/monthSupply
- 50mg / 100mgStrengths
- Provider reviewedBefore anything ships
The people pictured are models, not patients.
RxSexual Health
Sildenafil
Your starting dose, and the step up if you need it.
40,000+ products sold · LegitScript certified
The standard option for on-demand ED treatment, available in 50mg and 100mg. A board-certified physician reviews your file and prescribes the strength that's clinically appropriate for you.
- Works in 30 to 60 min
- Take only as needed
- Oral tablet
- Provider-reviewed
What's Included
- ✓Medication and supplies
- ✓Provider visit and unlimited follow-ups
- ✓Free expedited shipping
Pause, change, or cancel anytime from your account.
Strength
Doses per month
How Would You Like To Pay?
Choose Your Plan
1-Month Plan
$6250mg · 10 doses/mo
- $62 Billed Today
- Then $62 Every Month
- Cancel Anytime
Or pay with
$62 billed today, then every month until canceled.
Not prescribed? Full refund.
After checkout you complete a short medical review in your member portal, and a US-licensed provider reviews it before any sildenafil ships.
Full refund if not prescribed Free, discreet shipping Cancel anytime
Order today and here is what happens next
- TodayChoose a plan, then a short online intake
- Within about 24 hoursA US-licensed provider reviews your request
- Ships in 3 to 5 daysEstimated ship date, if prescribed
- Full refund
- If a provider does not prescribe it
- Licensed clinicians
- An independent US-licensed clinician reviews every request
- US-licensed pharmacy
- Prepares and ships your prescription
- Discreet delivery
- Plain, unmarked packaging
Common questions
Should treatment start at 50mg or move straight to 100mg?
Most people start at 50mg. It has the deepest evidence base for a first prescription and the lowest rate of pronounced side effects. If 50mg doesn't work well enough for you, your provider can adjust your file to 100mg, which shares the same mechanism and duration with a somewhat stronger side-effect profile. Clinical evidence shows no additional benefit above 100mg.
Is sildenafil the same medication as Viagra?
Yes. Sildenafil is the active compound sold under the brand name Viagra, first approved by the FDA in 1998 and evaluated across 21 clinical trials involving more than 3,000 men. Generic sildenafil uses the identical molecule at the identical strength, in either 50mg or 100mg; only the name and, typically, the price differ.
Is there any added benefit to taking more than 100mg?
No. The clinical trials behind sildenafil's 1998 approval, more than 3,000 men across 21 studies, found no additional efficacy beyond the 100mg dose. It sits at the top of the documented dose-response curve, which is why your file won't show anything higher prescribed.
LegitScript certifiedCert. 50087439- US-licensed pharmacyPrepares every prescription
- Independent cliniciansUS-licensed, in your state
- 40,000+Products sold
- All 50 statesFree, discreet shipping
- No insurance requiredOne price, shown up front
Dinner for two
Your starting dose, and the step up if you need it.
- 01Works in 30 to 60 min
- 02Take only as needed
- 03Oral tablet
- 04Provider-reviewed
The people pictured are models, not patients.
Why Sildenafil
On your schedule, as needed
Take one tablet about an hour before sex. There is nothing to take on the days you do not want it.
The active ingredient in Viagra
Sildenafil is the same active ingredient found in branded Viagra, compounded by a US-licensed pharmacy at 50 mg or 100 mg.
A provider reviews you first
A US-licensed provider checks your health history and heart risks before prescribing. Real pricing, shown up front.
How we compare
Sildenafil, without the waiting room.
HealthRX.comTypical in-person visit
Start online, no appointment or waiting roomBook, travel and wait
A US-licensed clinician reviews your history
Price shown before you startDepends on the visit and insurance
No insurance requiredOften billed through insurance
Delivered to your door in a plain boxPick up at the pharmacy
Full refund if you are not prescribedVisit fees usually apply either way
Understand your treatment
A focused option for the physical response.
Sildenafil inhibits PDE5, an enzyme involved in breaking down the chemical signal that helps blood vessels relax during sexual stimulation. That mechanism explains its place in erection-focused care. It also explains why sildenafil is a different conversation from a medication aimed at desire. When comparing options, the practical questions are the planned timing, tablet strength and whether you prefer an as-needed approach.
A closer look
A focused option for the physical response.
Sexual stimulation
PDE5 pathway
Blood-flow response
Make a more informed choice
Sildenafil vs. tadalafil
Both are PDE5 inhibitors. Their duration and treatment schedules differ. Sildenafil is commonly discussed as an as-needed option; the tadalafil catalog includes both as-needed and daily formulations.
Explore the ingredient research
- Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA. Oral sildenafil in the treatment of erectile dysfunction. N Engl J Med. 1998;338(20):1397-1404.
- Fink HA, et al. Sildenafil for male erectile dysfunction: a systematic review and meta-analysis. Arch Intern Med. 2002;162(12):1349-1360.
HealthRX.com verified facts
Sildenafil online: price and access
Sildenafil starts at $35 per month on 12-month plan; the lowest checkout charge is $44 (billed monthly). A prescription is never guaranteed. A licensed provider reviews each request before a pharmacy can dispense treatment.
Catalog verified August 26, 2026. Source: HealthRX.com checkout catalog and refund policy. Monthly equivalent divides the discounted plan charge by the number of months; checkout may collect a multi-month total.
A straightforward path to care
Select your plan
Choose your treatment options and complete secure checkout. Then complete the online health intake.
Provider review
A US-licensed provider reviews your history and prescribes sildenafil if it is appropriate for you.
Ships to your door
A US-licensed pharmacy compounds your dose and ships it free in discreet packaging.
Ongoing support
Message your care team anytime, and your provider can move you between 50 mg and 100 mg based on how you respond.
- Provider review
- An independent US-licensed clinician reviews every request.
- Free, discreet shipping
- Filled by a US-licensed pharmacy and shipped in discreet packaging.
- Not prescribed?
- You get a full refund for the medication.
About Sildenafil
Sildenafil belongs to the PDE5 inhibitor class. It works by blocking the PDE5 enzyme responsible for breaking down cGMP in penile tissue, which lets smooth muscle there relax and blood flow rise once stimulation begins. That last part matters: sildenafil requires sexual arousal to work, so it won't produce an erection in your body on its own, no matter how much time has passed since your dose. The mechanism is identical at 50mg and 100mg; what changes at the higher dose is how much drug is available to occupy the enzyme, and trial evidence shows no additional benefit from exceeding 100mg.
- FDA-approved since 1998, the longest track record of any option your provider can prescribe here
- Evaluated across 21 clinical trials and more than 3,000 participants in the approval data
- Peaks in your system around the one-hour mark, ahead of tadalafil's roughly two-hour peak
- 100mg available in your file if 50mg isn't enough, with no documented benefit shown above it
- Active four to six hours at either strength, timed to your plans rather than a daily dose
Arousal releases nitric oxide
Sexual stimulation signals the release of nitric oxide, which raises cGMP in the smooth muscle of the penis.
Sildenafil blocks the PDE5 enzyme
PDE5 normally breaks cGMP down. Sildenafil inhibits it, so cGMP levels stay higher.
Smooth muscle relaxes, blood flows in
The vessels widen and blood fills the erectile tissue, supporting a firmer erection.
More blood flow during arousal, which is why sexual stimulation is still required.
What the research shows
Sildenafil is one of the most studied medications for erectile dysfunction, with decades of randomized controlled trials. Here is what that research found.
69% versus 22%
of intercourse attempts succeeded on sildenafil compared with placebo in a randomized controlled trial.
Goldstein et al., N Engl J Med 1998
57% versus 21%
of attempts succeeded on sildenafil versus placebo across pooled trials of 2,283 men.
Fink et al., Arch Intern Med 2002
As needed, by mouth
An oral tablet taken about an hour before sex, with no injections or in-office visits required.
References
- Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA. Oral sildenafil in the treatment of erectile dysfunction. N Engl J Med. 1998;338(20):1397-1404.
- Fink HA, et al. Sildenafil for male erectile dysfunction: a systematic review and meta-analysis. Arch Intern Med. 2002;162(12):1349-1360.
Sildenafil or Tadalafil
Two proven options, different timing
| Sildenafil | Tadalafil | |
|---|---|---|
| Onset | About 30 to 60 minutes | About 30 to 60 minutes |
| Duration | About 4 to 6 hours | Up to 36 hours |
| Food effect | A heavy meal can slow it | Not affected by food |
| If side effects occur | Clear sooner, shorter half-life | Can persist longer |
| Best for | Planned, shorter windows | Spontaneity across a longer window |
| Active ingredient | Same as branded Viagra | Same as branded Cialis |
What to expect
Most people notice an effect within thirty to sixty minutes, with concentration peaking near the one-hour mark, the same timeline at either strength. A high-fat meal slows absorption and can delay that peak by roughly an hour, so if precise timing matters to you, a lighter meal beforehand helps. Once active, the effect holds for about four to six hours at 50mg or 100mg. 100mg is generally reserved for people whose response to 50mg wasn't strong enough, and the documented side-effect pattern runs somewhat more pronounced at that dose: headache, mild indigestion, flushing, occasional blue-tinted vision, and nasal congestion, most of it transient.
30 to 60 minutes
It takes effect
Taken about an hour before sex, sildenafil reaches peak levels near the one hour mark.
1 to 4 hours
Your window
The effect is strongest in this window, and sexual stimulation is still needed for it to work.
4 to 6 hours
It wears off
Levels taper and the medication clears, since sildenafil has a short half-life.
After a few tries
Dial in your dose
If 50 mg is not enough, or side effects bother you, your provider can adjust between 50 mg and 100 mg.
Safety and side effects
Sildenafil is absolutely contraindicated with nitrate medications; combining the two can trigger a severe, dangerous fall in blood pressure. Your provider will also want to know about certain medications and health history before confirming a prescription at either strength: alpha-blockers, CYP3A4-inhibiting drugs such as some antifungal or HIV treatments, uncontrolled blood pressure, a prior heart attack or stroke, cardiovascular disease more broadly, or a personal history of NAION, a rare condition affecting the optic nerve. Side effects run somewhat more pronounced at 100mg than at 50mg.
Common
- Headache
- Flushing
- Nasal congestion
- Indigestion
Less common
- Changes in vision or a blue tinge to vision
- Sensitivity to light
- Dizziness
Seek care
- An erection lasting more than four hours, called priapism, which needs emergency care
- Sudden loss of vision or hearing, or chest pain, seek care right away
This is not a complete list of side effects. Never take sildenafil with nitrate medications such as nitroglycerin, or with recreational poppers, because the combination can cause a dangerous drop in blood pressure. Tell your provider about alpha-blockers, heart conditions, and every medication you take. Sildenafil is not for use by women or by anyone under 18.
Frequently asked questions
How safe is sildenafil alongside other medications?
Nitrates are an absolute contraindication because combining them with sildenafil can cause blood pressure to fall to dangerous levels, and alpha-blockers require caution too. Your provider reviews your cardiovascular history, including any prior heart attack, stroke, or NAION, before deciding whether sildenafil, and which strength, is clinically appropriate for you.
Other sexual health options
Approval is never automatic.
An independent US-licensed clinician reviews every request. If they decide the treatment is not right for you, you get a full refund for the medication.
Choose a planNo insurance required
Prescriptions are filled by a US-licensed pharmacy and shipped free, in discreet packaging, on every plan.
LegitScript-certified · Cert 50087439
Compounded medications are prepared by a US-licensed pharmacy and are not reviewed by the FDA for safety or effectiveness. Products are dispensed only after a licensed provider determines they are appropriate. Information here is educational and is not a substitute for medical advice.