Viagra
An oral tablet used to treat erectile dysfunction and pulmonary arterial hypertension.
Where Sildenafil is approved
All regulators →Of the three regulators tracked here, the first to approve Sildenafil was the US, on 27 Mar 1998. It is approved in 3 of the 3 regulators tracked here.
- 4 EU orphan designations, most recently for treatment of Leigh syndrome (13 Oct 2023, positive)
From the regulators' own registers: FDA Drugs@FDA, the EMA medicines list and Health Canada's Notice of Compliance database. Dates are the first listed approval of a product containing only this substance; combination products and nationally authorised EU medicines are not counted.
Sildenafil patents and exclusivity
Expiry tracker →Protections still running for marketed products containing Sildenafil, as listed by the regulators. Expired patents and exclusivities, and discontinued products, are not shown.
- 1 listed patent; the last listed expires 16 Dec 2033 (US 11123287).
- Exclusivity ODE-469: Orphan drug exclusivity: treatment of pulmonary arterial hypertension (pah) (who group i) in pediatric patients 1 to 17 years old to improv…, until 31 Jan 2030.
- Exclusivity NP: New product, until 16 Dec 2028.
Reproduced from the FDA Orange Book and Purple Book (checked 5 Oct 2026) and the European Commission's Union Register of medicinal products (CC BY 4.0; the EU expiry date is calculated exactly as the Commission's register displays it). Listed patents and dates are as submitted to or published by the regulator and may not reflect litigation, invalidation, settlements, lapsed fees or later extensions. This is not legal advice or a freedom-to-operate opinion, and it does not say when a generic or biosimilar will launch.
What health systems spend on Sildenafil
All medicines →From NHSBSA Prescription Cost Analysis (Open Government Licence v3.0) and CMS State Drug Utilization Data. Both are gross amounts: neither system publishes its discounts or rebates per drug. Products combining several substances are not counted here.
How Sildenafil works
All drug targets →- Phosphodiesterase 5A inhibitor InhibitorTarget: PDE5A phosphodiesterase 5A✓ In ChEMBL and the Guide to Pharmacology
- Eisenmenger syndromePhase 3
- Left ventricular diastolic dysfunctionPhase 3
- Beta thalassemiaPhase 3
- Chronic lung diseasePhase 3
- Congestive heart failurePhase 3
- Coronary vasospasmPhase 3
- Diabetes mellitusPhase 3
- Diastolic heart failurePhase 3
- GlaucomaPhase 3
- Heart failurePhase 3
Mechanisms and diseases from ChEMBL via the Open Targets Platform (release 26.09), ChEMBL record CHEMBL192, CC BY-SA 3.0. Targets checked against the IUPHAR/BPS Guide to PHARMACOLOGY (2026.3), ligand 4743, CC BY-SA 4.0. Trial phases are not approvals: approved uses are shown from the regulators' own records where we hold them.
Patient leaflets for Sildenafil
The package leaflet is the official guide for patients that comes with every medicine. These links go to the regulators that publish it.
- IEIreland: 48 products on the HPRA listEach product record links to the HPRA, which publishes the leaflet and SmPC.
- EUEuropean Union: Revatio, Viagra, Granpidam (generic), Mysildecard (generic), Sildenafil Actavis (generic), Sildenafil Teva (generic), Sildenafil ratiopharm (generic), Vizarsin (generic)EMA product information: package leaflet and summary of product characteristics in every EU language.
- UKUnited Kingdom: Search MHRA ProductsPatient information leaflets and SmPCs for UK-licensed products.
- USUnited States: Search DailyMedFDA-approved labels, including patient and medication guides.
Leaflets differ between brands and countries; always read the one that comes with your own medicine. This is regulatory information, not medical advice.
Reference identifiers for Sildenafil
- ATC code
- G04BE03
- ChEMBL
- CHEMBL192
- DrugBank
- DB00203
- PubChem CID
- 135398744
- CAS number
- 139755-83-2
- FDA UNII
- 3M7OB98Y7H
- Wikidata
- Q191521
- Wikipedia
- Sildenafil
Codes that identify this medicine in other databases, from Wikidata (CC0), matched by its ChEMBL ID. The ATC code is the WHO classification of what the medicine is used for.
What Viagra is used for
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 )
How it works
12.1 Mechanism of Action The physiologic mechanism of erection of the penis involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. Sildenafil enhances the effect of NO by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for degradation of cGMP in the corpus cavernosum. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum. When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil c…
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How this page is built
The facts on this page are pulled directly from official U.S. FDA datasets — they are not written from memory. Each field below names the dataset it came from, so you can check it yourself.
- FDA Drug Label (openFDA) ↗ Indications, mechanism of action and pharmacologic class
- Drugs@FDA ↗ First FDA approval date and the company holding the application
- FDA Drug Shortage Database ↗ Current US supply / shortage status
Plain-English summaries and drug-class explainers are written and reviewed by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 6 Oct 2026. How every register is built: methodology · fixes we have made: corrections log.