Generic Sildenafil vs Viagra

Side by side

Every row carries how well supported it is. A claim that only reflects common practice is labelled as such rather than presented as fact.

label

Stated on the FDA label

guideline

Clinical practice guideline

literature

Published literature

practice

Common practice, not documented

Which one

The honest summary is lopsided, which is unusual for this page type and is the reason this comparison is worth having. Two labels that are identical apart from a brand name, an AB therapeutic-equivalence code on both, a federal definition of bioequivalence that both satisfy, and a 655-fold gap in acquisition cost. There is no clinical finding here that favours the brand. What there is, at the margins, is FDA's own acknowledgement that inactive ingredients can matter to a minority of people — and none of the dollar figures above is a price you can pay, so check what your pharmacy actually charges before drawing a conclusion about your own bill.

Frequently asked questions

Is generic sildenafil as good as Viagra?

By the standard FDA applies, yes, and the standard is specific rather than rhetorical. Both carry the Orange Book code AB — "Products meeting necessary bioequivalence requirements" — and 21 CFR 314.3 defines therapeutic equivalents as "approved drug products that are pharmaceutical equivalents for which bioequivalence has been demonstrated, and that can be expected to have the same clinical effect and safety profile when administered to patients under the conditions specified in the labeling." To earn that, a sildenafil ANDA has to run the study FDA specifies for it: a single-dose, two-treatment, two-period crossover in healthy males at the 100 mg strength, with the 90% confidence interval falling "at least 80.00 percent and not more than 125.00." The two prescribing informations are then word for word the same apart from the brand name.

Why is Viagra 655 times the price if the drug is identical?

Because the two prices are set by different things. The generic rate is what competition does — the 2026-09-16 NADAC file prices 31 generic 100 mg NDCs at $0.12762 each. The brand rate is what a brand holder charges when the brand has stopped competing on price, and 4 VIAGRA NDCs sit at $83.63. FDA's own published expectation is far smaller than what actually happened here: it says "a single generic competitor can lead to price reductions of 30%, while five generics competing are associated with prices drops of nearly 85%." An 85% drop is a factor of about seven. This is a factor of 655, because the generic fell through the floor rather than the brand coming down to meet it.

What actually differs between the two tablets?

On the pair compared here — VIAGRA against Jubilant Cadista's ANDA 201156 — the excipient lists differ by one entry. VIAGRA's section 11 lists "microcrystalline cellulose, anhydrous dibasic calcium phosphate, croscarmellose sodium, magnesium stearate, hypromellose, titanium dioxide, lactose, triacetin, and FD & C Blue #2 aluminum lake"; the generic lists the same set with lactose monohydrate in place of lactose and no dye at all. One is a "blue, film-coated rounded-diamond-shaped" tablet, the other "white, film-coated, oval-shaped". That comparison is against one named application and does not generalise: there are 219 current sildenafil labels on DailyMed and their inactive ingredients are not all the same, which is precisely what 21 CFR 314.3 anticipates when it says pharmaceutical equivalents "do not necessarily contain the same inactive ingredients."

Can I pay the prices on this page?

No, and that is worth being blunt about because these figures circulate as though they were prices. NADAC is the National Average Drug Acquisition Cost: a survey of what retail community pharmacies reported paying their wholesalers, published per NDC by CMS. It sits before the dispensing fee, before any markup, before rebates and before margin. $0.12762 is what the bottle cost the pharmacy, not what the counter charges you, and $83.63 is not a VIAGRA price either. The reason to quote NADAC at all is that it is the one figure the federal government publishes for both products on the same day on the same basis, which makes the 655× ratio meaningful even though neither number is a price.

Does the brand have to still be on sale for a generic to exist?

No, and the Orange Book spells out what happens when it is not: "where the RLD has been withdrawn from sale for reasons other than safety or effectiveness, FDA may select an ANDA that is therapeutically equivalent to this RLD as the reference standard." So the reference listed drug and the reference standard can come apart, and a discontinued brand can still be the RLD every generic points at. It does not apply to sildenafil. Checked on 2026-09-20, VIAGRA is current: all three strengths are marketing_status Prescription under NDA 020895, sponsor Viatris, and the 100 mg tablet is still priced in the NADAC file across four NDCs. Sildenafil is the ordinary case where the brand is still on the shelf and still 655 times the price.

Is the same true of Cialis and generic tadalafil?

Yes, at a smaller multiple, and the arithmetic comes from the same file on the same day. CIALIS 20 mg is $53.84 against $0.15815 for generic tadalafil 20 mg — 340×. Note how much the multiple moves within one brand: the CIALIS 5 mg row is only 90.2×, because generic tadalafil 5 mg and 20 mg are priced within half a cent of each other while the branded 5 mg is a ninth of the branded 20 mg. The lesson is that a brand-to-generic ratio describes two specific listings on one specific day, not a rule about brands.

Should I ask my prescriber to write "dispense as written"?

Only if you have a specific reason, and "the brand is the real one" is not one. Writing DAW blocks the substitution that the AB code exists to permit, and on this evidence it buys a dye and a shape. The reasons that do hold up are narrow: a documented problem with a particular generic, a plan design that genuinely makes the brand cheaper for you, or a known reaction to a specific excipient — and in that last case the fix is usually a different manufacturer, not the brand, because the excipient lists differ between generics too. This is a conversation for your prescriber and your pharmacist, who can see what your plan actually charges.

Sources

1. [1]CMS National Average Drug Acquisition Cost (NADAC), weekly file dated 2026-09-16. Source of every dollar figure above: VIAGRA 100 MG TABLET at $83.63 across 4 NDCs, SILDENAFIL 100 MG TABLET at $0.12762 across 31 NDCs, CIALIS 20 MG TABLET at $53.84 and TADALAFIL 20 MG TABLET at $0.15815. NADAC records what retail community pharmacies reported paying on invoice, per NDC — not a retail price, a cash price or a copay
2. [2]FDA label — VIAGRA (sildenafil citrate) tablets, film coated, Pfizer Laboratories Div Pfizer Inc (DailyMed SPL 0b0be196-0c62-461c-94f4-9a35339b4501; approval block NDA 020895, marketing category NDA). Source of "VIAGRA is indicated for the treatment of erectile dysfunction.", "For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity.", and the section 11 description "VIAGRA is formulated as blue, film-coated rounded-diamond-shaped tablets… each tablet contains the following inactive ingredients: microcrystalline cellulose, anhydrous dibasic calcium phosphate, croscarmellose sodium, magnesium stearate, hypromellose, titanium dioxide, lactose, triacetin, and FD & C Blue #2 aluminum lake."
3. [3]FDA label — SILDENAFIL tablets, film coated, Jubilant Cadista Pharmaceuticals Inc. (DailyMed SPL 1ed2420b-478a-ca9c-0330-85c845acdd32; approval block ANDA 201156, marketing category ANDA). The generic label compared word for word above. Source of "Sildenafil tablets are indicated for the treatment of erectile dysfunction." and "Sildenafil tablets, USP are formulated as white, film-coated, oval-shaped tablets… each tablet contains the following inactive ingredients: anhydrous dibasic calcium phosphate, croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, titanium dioxide, and triacetin."
4. [4]21 CFR 314.3, Definitions (via the eCFR API, current text as of 2026-09-01). Source of "Bioequivalence is the absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study."; of "Pharmaceutical equivalents are drug products in identical dosage forms and route(s) of administration that contain identical amounts of the identical active drug ingredient… do not necessarily contain the same inactive ingredients"; of "Therapeutic equivalents are approved drug products that are pharmaceutical equivalents for which bioequivalence has been demonstrated, and that can be expected to have the same clinical effect and safety profile when administered to patients under the conditions specified in the labeling."; of "Reference listed drug is the listed drug identified by FDA as the drug product upon which an applicant relies in seeking approval of its ANDA."; and of "Reference standard is the drug product selected by FDA that an applicant seeking approval of an ANDA must use in conducting an in vivo bioequivalence study required for approval."
5. [5]FDA — Draft Guidance on Sildenafil Citrate, oral tablet, October 2024 (Unique Agency Identifier PSG_020895, referencing NDA 020895 and NDA 021845). "Recommended Study: One in vivo bioequivalence study with pharmacokinetic endpoints", "Type of study: Fasting", "Design: Single-dose, two-treatment, two-period crossover in vivo", "Strength: 100 mg", "Subjects: Healthy males", "Bioequivalence based on (90% CI): Sildenafil", and the waiver of in vivo testing for the 20, 25 and 50 mg strengths. Header: "Contains Nonbinding Recommendations / Draft – Not for Implementation"
6. [6]FDA guidance for industry — Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs Submitted Under an ANDA, CDER, May 2026. Source of the acceptance limits, verbatim: "For unscaled average BE analyses, to pass a confidence interval limit of 80 to 125 percent, the rounded confidence interval value should be at least 80.00 percent and not more than 125.00."
7. [7]FDA — Approved Drug Products With Therapeutic Equivalence Evaluations (Orange Book), Preface to the Forty Sixth Edition. Source of "AB, AB1, AB2, AB3… Products meeting necessary bioequivalence requirements"; of the five therapeutic-equivalence criteria beginning "(1) they are approved as safe and effective"; and of "where the RLD has been withdrawn from sale for reasons other than safety or effectiveness, FDA may select an ANDA that is therapeutically equivalent to this RLD as the reference standard."
8. [8]FDA — Generic Drug Facts (CDER). Source of "FDA-approved generic medicines work in the same way and provide the same clinical benefit and risks as their brand-name counterparts."; of the five ways an applicant must show sameness, including "The label is the same as the brand-name medicine's label (with certain exceptions)." and "The generic medicine is bioequivalent to the brand-name medicine."; and of "a single generic competitor can lead to price reductions of 30%, while five generics competing are associated with prices drops of nearly 85%."
9. [9]FDA — Generic Drugs: Questions & Answers (content current as of 09/18/2026). Source of "Bioequivalence generally means the generic drug delivers the same amount of active ingredient to a patient at the same rate and to the same extent as the brand name drug. This is a key requirement before FDA approves a generic drug." and of the inactive-ingredient answer quoted above: "In most cases no, but in a minority of patients, inactive ingredients may affect tolerability or absorption. This is usually minor and uncommon – but worth clinical attention if patients report concerns."
10. [10]Drugs@FDA via the openFDA drugsfda endpoint, queried 2026-09-20. VIAGRA, NDA 020895, sponsor VIATRIS: all three products marketing_status "Prescription", reference_drug "Yes", te_code "AB", with reference_standard "Yes" on the EQ 100MG BASE product and "No" on the 25 and 50 mg. Generic sildenafil citrate tablet ANDAs (including ANDA 209302 and ANDA 216383): reference_drug "No", te_code "AB"

Next steps

• Sildenafil vs tadalafil
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