Prescription required Phosphodiesterase 5 (PDE5) inhibitor

Buy Sildenafil (Viagra) — Online Prescription

Sildenafil — the active ingredient behind brand-name Viagra — is a prescription-only medication in the United States, available as a far less expensive generic since 2017. Here's what it actually treats, real dosing, brand vs. generic pricing, and what determines whether it's safe for you.

Medically reviewed Medically reviewed by Angelo DeFazio, R.Ph. — NPI 1629115530 · Last updated 2026-08-31

Medical disclaimer This page is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or pharmacist before starting, stopping, or changing any medication. Never disregard professional medical advice or delay seeking it because of something you have read on this site.
Active ingredientSildenafil citrate
Dosage formTablet (25mg, 50mg, 100mg)
Administration routeOral
FDA Drug Facts — Viagra

Indications: 1 INDICATIONS AND USAGE VIAGRA is indicated for the treatment of erectile dysfunction. VIAGRA is a phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED) ( 1 )

Contraindications: 4 CONTRAINDICATIONS • Administration of VIAGRA to patients using nitric oxide donors, such as organic nitrates or organic nitrites in any form. VIAGRA was shown to potentiate the hypotensive effect of nitrates ( 4.1 , 7.1 , 12.2 ) • Known hypersensitivity to sildenafil or any component of tablet ( 4.2 ) • Administration with guanylate cyclase (GC) stimulators, such as riociguat ( 4.3 ) 4.1 Nitrates Consistent with its known effects on the nitric oxide/cGMP pathway [ see Clinical Pharmacology (12…

Excerpted from the FDA-approved prescribing information. Read the full label on Drugs@FDA →

openFDA label data — Updated 2026-09-02
Quick answer

No, sildenafil (Viagra) is not sold over the counter in the US — it's prescription-only in every form, brand and generic alike. Generic sildenafil has been available since December 2017 and is typically far less expensive than brand-name Viagra, with no difference in the medication itself. Once you have a valid prescription, we can fill it quickly and discreetly.

1998Year the FDA first approved sildenafil (as Viagra)
2017Year the first FDA-approved generic launched in the US
4+ hrsErection duration that needs emergency care (priapism)

Is sildenafil available over the counter?

No — in the United States, sildenafil requires a prescription, whether you're asking about brand-name Viagra or generic sildenafil. A prescriber needs to evaluate you first, mainly to rule out a dangerous interaction with nitrate medications and to confirm your cardiovascular health can tolerate the physical exertion of sexual activity.

A lot of the "is Viagra OTC" confusion actually comes from a real, but different, fact: in November 2017, the UK's Medicines and Healthcare products Regulatory Agency (MHRA) reclassified 50 mg sildenafil (sold there as Viagra Connect) from prescription-only to a "pharmacy medicine" — meaning a UK pharmacist can sell it after an in-person consultation, with no doctor's prescription required. That's a genuinely different regulatory system; it has no effect on US law, and no dose of sildenafil is available without a prescription at any US pharmacy, in person or online.

Legitimate ways to get evaluated quickly
  • Telehealth — many services can evaluate you and send a prescription to your pharmacy same-day
  • Your primary care provider or a urologist
  • Ask us — we can often coordinate with your prescriber's office
Red flags
  • Any site offering sildenafil with no prescription or medical evaluation
  • "Herbal Viagra" or unregulated supplements claiming the same effect
  • Unusually cheap pricing with no pharmacy license or address listed

Erectile dysfunction medications are among the most commonly seized categories of counterfeit drugs by US Customs and the FDA — counterfeit product may contain the wrong dose, no active ingredient at all, or undisclosed and dangerous additional drugs. See the FDA's BeSafeRx guidance on identifying a legitimate online pharmacy.

What sildenafil actually treats

Sildenafil has two separate, distinct FDA approvals under two different brand names — most people only know about one of them:

Brand Approved use Typical dosing
Viagra Erectile dysfunction (ED) 25–100 mg, taken as needed before sexual activity
Revatio Pulmonary arterial hypertension (PAH) — high blood pressure in the lung arteries Different regimen, taken regularly, unrelated to sexual activity

Both contain the same active ingredient, sildenafil citrate, at different doses and for entirely different purposes. If you were prescribed sildenafil and aren't sure which use applies to you, check with your prescriber — the two are not interchangeable in how or when they're taken.

Dosage: 25mg, 50mg, and 100mg

For erectile dysfunction, sildenafil comes in three strengths:

25 mgLower starting dose — often used with kidney/liver impairment or other medications
50 mgTypical starting dose for most adults
100 mgMaximum recommended dose

Take it roughly 30–60 minutes before sexual activity — effectiveness generally lasts about 4–5 hours, though this varies by person. A high-fat meal can delay how quickly it kicks in (though not how well it ultimately works), so timing around a heavy meal is worth planning for. Never take more than one dose in 24 hours, and never adjust your own dose beyond what's prescribed.

Generic sildenafil vs. brand-name Viagra

Brand

Viagra

Active ingredient
Sildenafil citrate
FDA approval
1998
Cost
Significantly higher than generic for the identical medication
Generic

Sildenafil

Active ingredient
Sildenafil citrate — chemically identical
FDA approval
First generic approved December 2017
Cost
Typically far less expensive, same FDA bioequivalence standard

Generic sildenafil must meet the same FDA bioequivalence standard as brand-name Viagra — same active ingredient, same dose, same expected effect. There is no clinical reason to pay a brand-name premium once a generic is available, which it has been in the US since 2017.

Sildenafil vs. tadalafil (Cialis)

Both are PDE5 inhibitors and work the same basic way, but they differ enough in practice that it's worth understanding before asking your prescriber which fits you better:

Sildenafil (Viagra) Tadalafil (Cialis)
Duration of effect ~4–5 hours Up to 36 hours
Dosing pattern As-needed only As-needed, or a lower daily dose
Food effect High-fat meals delay onset Minimal food effect

Neither is universally "better" — it's a fit question based on how spontaneous vs. planned you want sexual activity to be, and how each affects you individually. See our Cialis (Tadalafil) page for the full picture on that option.

Side effects, nitrates, and safety

Sildenafil is a PDE5 inhibitor — it relaxes blood vessels to improve blood flow. That mechanism is exactly why it carries real safety requirements:

Never combine with nitrates Sildenafil is contraindicated with nitrate medications (including as-needed nitroglycerin for chest pain) and with guanylate cyclase stimulators like riociguat — the combination can cause a severe, dangerous drop in blood pressure. Always tell your prescriber and pharmacist about every medication you take, including ones you only use occasionally.

Common side effects include headache, flushing, upset stomach, and nasal congestion. Less commonly, sildenafil can cause temporary vision changes (including a blue tinge to vision) and back pain. Seek emergency care for an erection lasting longer than 4 hours (priapism, which can cause permanent damage if untreated) or sudden vision or hearing loss in one or both eyes/ears.

The FDA label also advises caution for anyone whose cardiovascular health makes sexual activity inadvisable — this is exactly the evaluation a prescriber and pharmacist are positioned to do, and an unregulated online seller is not.

Sildenafil for women, and other questions

Sildenafil is not FDA-approved for use in women — its safety and effectiveness for female sexual dysfunction haven't been established, despite it being a common search. If low sexual desire is the underlying concern, flibanserin (Addyi) is a separate medication FDA-approved specifically for premenopausal women with acquired, generalized low sexual desire — see our Addyi (Flibanserin) page.

This page covers human use only. Veterinary use of sildenafil (for a different condition, in animals) is a matter for your veterinarian, not this page.

Buying, pricing, and savings

  • Choose generic. Ask us to fill generic sildenafil unless your prescriber specifically calls for brand-name Viagra — same medication, same FDA standard, meaningfully lower price.
  • Check the cash price. For a medication like this, the cash price is sometimes lower than an insurance copay, especially at higher quantities — ask before assuming insurance is cheapest.
  • Ask about savings programs. Manufacturer or discount savings options may apply to your specific prescription — ask our pharmacists before paying full price anywhere.
  • Speed and discretion. Call us at (860) 522-9289 once you have a prescription and we'll have it ready quickly.
FDA drug shortage status

No active shortage reported — No shortage records found for this generic name.

FDA openFDA — Updated 2026-09-02
Fair price reference

National Average Drug Acquisition Cost (NADAC): $0.136 per tablet (SILDENAFIL 100 MG TABLET). This is the average price pharmacies pay wholesalers — not your out-of-pocket cost — published by CMS for pricing transparency.

CMS NADAC — Updated 2026-09-02

Sildenafil (Viagra) Prices in the USA

These are estimated average US retail cash prices — not insurance copays, not coupon prices, and not a quote from Arrow Pharmacy. Actual cost varies significantly by pharmacy, region, quantity, and insurance. Generic sildenafil has been available since December 2017 and is chemically identical to brand-name Viagra — nearly everyone fills the generic today. Call us at (860) 522-9289 for a current price.

Dosage Brand-name avg. price Generic avg. price
25 mg (30 tablets) $700–1,000 (Viagra) $15–35
50 mg (30 tablets) $800–1,200 (Viagra) $20–45
100 mg (30 tablets) $900–1,300 (Viagra) $25–60
Average market pricing — Updated 2026-08-31

Frequently asked questions

Is sildenafil (Viagra) available over the counter in the US?

No. Sildenafil is prescription-only in the United States, whether sold as brand-name Viagra or as generic sildenafil. A prescriber needs to confirm it's safe for you — mainly to rule out a dangerous interaction with nitrate heart medications — before you take it. (The UK allows a pharmacist-supervised non-prescription sale under the name Viagra Connect — that's a different country's regulatory system and doesn't apply in the US.)

Is generic sildenafil the same as Viagra?

Yes. Generic sildenafil citrate contains the same active ingredient, at the same doses, and must meet the same FDA bioequivalence standards as brand-name Viagra. The FDA approved the first generic in December 2017. The main difference is price — generics are typically far less expensive, with no clinical downside.

What is the standard sildenafil dosage?

For erectile dysfunction, 50 mg taken about an hour before sexual activity is the typical starting dose, adjusted by your prescriber to 25 mg or 100 mg (the maximum) based on effectiveness and side effects. It should be taken no more than once daily. For pulmonary arterial hypertension (brand name Revatio), dosing is different and unrelated to sexual activity timing.

How long does sildenafil last, and how long does it take to work?

Most people notice an effect within 30–60 minutes, with the window of effectiveness lasting about 4–5 hours for most people, though this varies by individual. A high-fat meal can delay how quickly it starts working, though it doesn't reduce overall effectiveness — taking it on a fuller stomach just means a longer wait.

Why can't I take sildenafil with nitrate medications?

Sildenafil can cause a dangerous, potentially life-threatening drop in blood pressure when combined with nitrates (such as nitroglycerin) or guanylate cyclase stimulators like riociguat. This combination is contraindicated on the FDA label — always tell your prescriber and pharmacist about every medication you take, including as-needed nitroglycerin you might not think to mention.

Can I drink alcohol with sildenafil?

Moderate alcohol is generally not a strict contraindication, but both alcohol and sildenafil can independently lower blood pressure, and combining them can increase dizziness, flushing, and headache. Heavy drinking can also impair the ability to get or maintain an erection regardless of the medication. Keep it light, and ask your pharmacist if you have any cardiovascular risk factors.

Is sildenafil approved for anything besides erectile dysfunction?

Yes — under the brand name Revatio, sildenafil is separately FDA-approved to treat pulmonary arterial hypertension (high blood pressure in the arteries of the lungs), at different doses than the ED indication. These are distinct, FDA-reviewed uses of the same active ingredient, not an off-label workaround.

Can women take sildenafil?

Sildenafil is not FDA-approved for use in women, and its safety and effectiveness for female sexual dysfunction haven't been established. If low sexual desire is the concern, flibanserin (Addyi) is a separate medication that is FDA-approved for that specific purpose in premenopausal women — see our Addyi page for details.

Does sildenafil expire, and does it still work after that date?

Yes, like all medications it has an expiration date, and potency can decline afterward — the FDA doesn't guarantee effectiveness or safety past it. Don't use expired sildenafil; ask your pharmacist about disposal and getting a current prescription filled.

What's the difference between sildenafil and tadalafil (Cialis)?

Both are PDE5 inhibitors that work the same basic way, but tadalafil lasts much longer (up to 36 hours, vs. about 4–5 for sildenafil) and is also approved for daily use, while sildenafil is taken on-demand only. Which fits better depends on how you want to plan around it — that's worth discussing with your prescriber.

How much does sildenafil cost, and how can I save?

Generic sildenafil is inexpensive at the wholesale level — CMS pricing data puts the national average acquisition cost around $0.14 per 100 mg tablet — though your actual price depends on dose, quantity, and insurance. Always ask for generic unless your prescriber specifies brand-name Viagra, and ask your Arrow Pharmacy pharmacist for a cash-price quote before assuming insurance is your cheapest option — it sometimes isn't.