On this page Jump to a section
- Key facts
- What was Viagra originally for?
- Viagra history timeline
- Who created Viagra?
- What sildenafil does
- What did men do before Viagra?
- What came next
- What each path includes
- Safety checks before ED medication
- If ED is the problem you want treated now
- Mendoxa plans and prices
- FAQ
- How we wrote this
- Sources and references
Key facts at a glance
- Original target
- Hypertension and angina (chest pain from heart disease)Ghofrani et al. 2006 · PMC
- Where and code name
- Pfizer team at Sandwich, UK, formed in 1986; compound UK-92,480Ghofrani et al. 2006 · PMC
- FDA approval for ED
- March 27, 1998 (VIAGRA, NDA 020895)Drugs@FDA: VIAGRA (sildenafil)
- US generic launch
- Teva announced its US launch of generic Viagra tablets on December 11, 2017Teva launch announcement · SEC filing
- Compounded status
- The Mendoxa compounded tablet is not FDA-approvedFDA compounding Q&A
What was Viagra originally developed for?
It was a cardiovascular research candidate before it was an ED medicine. Pfizer’s team in Sandwich, UK, pursued angina and hypertension; the compound’s research code was UK-92,480 (Ghofrani, Osterloh and Grimminger’s development history). “Originally developed for” describes the research target, rather than an earlier approved use of Viagra (sildenafil).
The turning point came during clinical development. Volunteers reported erections in 1992 studies; the first study in men with ED followed in late 1993 (Ghofrani, Osterloh and Grimminger’s development history; Viagra (sildenafil) label). An unexpected observation prompted deliberate follow-up research.
Viagra history timeline, 1982–2017
Each row links the primary record we checked. Dates are approval or publication dates, not launch dates, unless stated.
| Year | Milestone | Primary source |
|---|---|---|
| 1982 | Intracavernous papaverine injection reported for erectile failure | Virag, Lancet 1982 · PubMed |
| 1986 | Pfizer forms a project team at Sandwich, UK, to develop a selective PDE5 inhibitor, within a search for angina drugs | Ghofrani et al. 2006 · PMC |
| 1992 | Healthy-volunteer studies of UK-92,480 (sildenafil); some volunteers report erections (Viagra (sildenafil) label) | Ghofrani et al. 2006 · PMC |
| 1993 | Angina results look less promising by mid-1993; first clinical study in men with ED in late 1993. Pfizer files the priority application for its “treatment of impotence” patent (June 1993) | Ghofrani et al. 2006; US 6,469,012 |
| 1995 | FDA approves CAVERJECT (alprostadil) injection | Drugs@FDA: CAVERJECT (alprostadil) |
| Mar 27, 1998 | FDA approves VIAGRA (sildenafil citrate) tablets, a new molecular entity | Drugs@FDA: VIAGRA (sildenafil) |
| Aug 19, 2003 | FDA approves LEVITRA (vardenafil) | Drugs@FDA: LEVITRA (vardenafil) |
| Nov 21, 2003 | FDA approves CIALIS (tadalafil) | Drugs@FDA: CIALIS (tadalafil) |
| Jun 3, 2005 | FDA approves REVATIO (sildenafil) tablets; the review notes approval for pulmonary arterial hypertension (PAH) | Drugs@FDA: REVATIO (sildenafil); Ghofrani et al. |
| Apr 27, 2012 | FDA approves STENDRA (avanafil) | Drugs@FDA: STENDRA (avanafil) |
| Dec 11, 2017 | Teva announces the exclusive US launch of generic Viagra (sildenafil citrate) tablets | Teva press release (SEC filing) |
Sources: Ghofrani, Osterloh & Grimminger 2006; Drugs@FDA records for VIAGRA (sildenafil), CIALIS (tadalafil), LEVITRA (vardenafil), STENDRA (avanafil), REVATIO (sildenafil) and CAVERJECT (alprostadil); PubMed; Google Patents; SEC. Accessed Oct 29, 2026.
Who created Viagra?
Pfizer’s scientists developed Viagra as a team. The Ghofrani, Osterloh and Grimminger’s development history places the project at Sandwich, UK, starting in 1986. Its co-author Ian Osterloh worked at Pfizer.
The patent answers a narrower question about inventorship. Pfizer’s “Pyrazolopyrimidinones for the treatment of impotence” patent names Peter Ellis and Nicholas Kenneth Terrett as inventors (US 6,469,012). Those names identify the inventors on that patent; they do not describe every contributor to the development of Viagra (sildenafil).
What sildenafil does: the PDE5 mechanism
Sildenafil inhibits PDE5, an enzyme that breaks down cGMP. During sexual stimulation, cGMP helps smooth muscle in the penis relax so blood can flow in; sildenafil slows its breakdown (Viagra (sildenafil) label).
Sexual stimulation is still needed: sildenafil does not produce its intended effect without it (Viagra (sildenafil) label). For practical questions, read our sildenafil guide or how long Viagra lasts.
What did men do before Viagra?
Penile injections were already being used. Virag’s 1982 Lancet report on papaverine injection predates the FDA approvals of CAVERJECT (alprostadil) in 1995 and VIAGRA (sildenafil) in 1998.
These options still exist. NIDDK lists injectable medicines, a urethral suppository, vacuum erectile devices, penile implants and counseling alongside oral PDE5 medicines. See our guides to the ED shot and the vacuum erection device.
What came next: Cialis, Levitra, Stendra and generics
Two more PDE5 inhibitors received FDA approval in 2003: LEVITRA (vardenafil) in August and CIALIS (tadalafil) in November. STENDRA (avanafil) followed in 2012. Compare them in our guides to tadalafil, vardenafil and avanafil.
When did generic Viagra come out in the US? Teva announced the exclusive US launch of generic Viagra (sildenafil citrate) tablets on December 11, 2017 (Teva press release filed with the SEC). Generic sildenafil shares the active ingredient of Viagra (sildenafil). For today’s costs, see Viagra cost; for the pill itself, what Viagra looks like.
The same ingredient also has a different approved use. REVATIO (sildenafil) received FDA approval on June 3, 2005; the Ghofrani, Osterloh and Grimminger’s development history documents its pulmonary arterial hypertension indication. A shared ingredient does not make the products’ prescribing instructions interchangeable.
What each path includes
History explains the options; your health decides between them. Use this table to prepare questions for a prescriber, not to self-select treatment.
| Path | What it includes | Boundary |
|---|---|---|
| Brand or generic sildenafil | A single active ingredient, taken as needed (Viagra (sildenafil) label) | Prescription required; requires sexual stimulation; not with nitrates |
| Another PDE5 tablet | Tadalafil, vardenafil or avanafil (Cialis (tadalafil) label; Drugs@FDA: LEVITRA (vardenafil), STENDRA (avanafil)) | Ask the prescriber how the specific medicine fits your needs |
| Non-pill options | Injections, urethral suppository, vacuum device or implant (NIDDK) | Ask which options need training or specialist assessment |
| Mendoxa 3-in-1 visit | Online review by independent licensed providers of a compounded tablet with sildenafil, tadalafil and apomorphine (APOKYN (apomorphine) injection label; this is not approval of an ED combination) | Prescription required; compounded drugs are not FDA-approved |
Sources: Viagra (sildenafil) label; Cialis (tadalafil) label; APOKYN (apomorphine) label; NIDDK treatment; FDA compounding Q&A; Mendoxa care information. Accessed Oct 29, 2026.
Choose the question that fits your situation:
- New to ED care? Start an online visit with your medication list and describe what has been happening.
- Already tried a tablet? Tell the provider which one and what happened; use our sildenafil vs tadalafil comparison to prepare questions.
- Want to understand other approaches? Review ED medications, the ED shot and vacuum devices before discussing your options.
Could Mendoxa ED care fit you?
Online ED visit · Prescription required · Independent licensed providers · Not available in California
Safety checks before ED medication
- Sildenafil and tadalafil are contraindicated with organic nitrates or riociguat (Viagra (sildenafil) label; Cialis (tadalafil) label).
- An erection lasting more than 4 hours needs immediate medical care (Viagra (sildenafil) label; Cialis (tadalafil) label).
- Stop and seek care for sudden vision loss or sudden decrease or loss of hearing (Viagra (sildenafil) label; Cialis (tadalafil) label).
- Common adverse effects include headache and flushing with sildenafil, and headache, indigestion and back pain with tadalafil (Viagra (sildenafil) label; Cialis (tadalafil) label).
- The APOKYN (apomorphine) label contraindicates use with 5HT3 antagonists such as ondansetron and warns about nausea and fainting.
Give the prescriber your full medicine list. See ED medication and nitrates and Viagra side effects for more detail.
If ED is the problem you want treated now
Make the history useful for your next decision. Start an online Mendoxa visit to ask whether its compounded tablet is appropriate for you. Independent licensed providers assess suitability. Prescription required.
The tablet combines sildenafil — the molecule behind the 1998 approval — with tadalafil and apomorphine; it is not FDA-approved. Ingredient references are the Viagra (sildenafil) label, Cialis (tadalafil) label and APOKYN (apomorphine) label; APOKYN is an injectable Parkinson’s treatment, and its label is not approval of this ED combination.
Tell the provider your goals, current medicines and previous treatment experience. Read about the combination ED tablet before the visit; the costs appear below.
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 (APOKYN label). It dissolves under the tongue. A licensed clinician decides if it fits you and selects the strength. Compounded medicines are not FDA-approved.
| Tablets per month | 1-month total | Per tablet (1 month) | 3-month total | 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 |
The 3-month total covers three months at the monthly tablet quantity shown.
If prescribed · Cancel anytime · Available in 49 states (not California). Prices from the Mendoxa intake at try.mendoxa.co/f/ed on Oct 29, 2026. The intake always shows the current price.
FAQ
What was Viagra originally used for?
Sildenafil was originally studied for angina and hypertension (Ghofrani, Osterloh and Grimminger’s development history). Its FDA approval as VIAGRA (sildenafil) in 1998 was for erectile dysfunction.
Who invented Viagra?
Pfizer’s scientists developed Viagra as a team. The Ghofrani, Osterloh and Grimminger’s development history places the project at Sandwich, UK, starting in 1986. Its co-author Ian Osterloh worked at Pfizer. The ED-use patent names Peter Ellis and Nicholas Kenneth Terrett; Viagra (sildenafil) label identifies the medicine.
When was Viagra invented and approved?
Pfizer’s PDE5 project began in 1986, volunteer studies of UK-92,480 ran in 1992 and the first ED study started in late 1993 (Ghofrani et al.). The FDA approved VIAGRA (sildenafil) on March 27, 1998.
Was Viagra discovered by accident?
The development history describes an unexpected observation followed by planned research: volunteers reported erections in 1992 studies, and ED studies began in late 1993 (Ghofrani, Osterloh and Grimminger’s development history; Viagra (sildenafil) label). That is more precise than calling the whole discovery an accident.
What did men use for ED before Viagra?
Penile injections preceded Viagra: Virag reported papaverine injection in 1982, and CAVERJECT (alprostadil) was approved in 1995. Our ED shot and vacuum device guides explain options to discuss today.
When did generic Viagra come out?
Teva announced the exclusive US launch of generic Viagra (sildenafil citrate) tablets on December 11, 2017 (Teva press release, SEC filing). Generic sildenafil still requires a prescription, as described in the Viagra (sildenafil) label.
Ready to see if the Mendoxa ED tablet fits you?
From $129/month if prescribed · Cancel anytime · Available in 49 states (not California)
How we wrote this
Written by the Mendoxa editorial team · Sources: DailyMed/FDA. Medical facts on this page come from the FDA-approved labels on DailyMed and Drugs@FDA; each drug name links to its label. We matched historical dates to FDA approval records and the NIH-hosted development history, and checked the linked sources on Oct 29, 2026; local source copies support this page. The Viagra (sildenafil) label and other ingredient labels describe separate approved medicines; they do not establish approval of Mendoxa’s compounded combination. FDA explains why compounded drugs are not FDA-approved.
Updated Oct 29, 2026. This page is general information, not medical advice. A licensed clinician decides what fits you.
References
- DailyMed: VIAGRA (sildenafil citrate) tablet, film coated, label revised 12/2017. Accessed Oct 29, 2026.
- DailyMed: CIALIS (tadalafil) tablet, film coated, label revised 3/2026. Accessed Oct 29, 2026.
- DailyMed: APOKYN (apomorphine hydrochloride) injection, label revised 6/2022. Accessed Oct 29, 2026.
- FDA (Drugs@FDA): VIAGRA (sildenafil) prescribing information, NDA 020895. Accessed Oct 29, 2026.
- FDA (Drugs@FDA): CIALIS (tadalafil) prescribing information, NDA 021368. Accessed Oct 29, 2026.
- FDA: Compounding and the FDA, questions and answers. Accessed Oct 29, 2026.
- Ghofrani HA, Osterloh IH, Grimminger F. Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond. Nat Rev Drug Discov. 2006;5(8):689-702. PMID 16883306. Accessed Oct 29, 2026.
- Drugs@FDA: VIAGRA (sildenafil citrate), NDA 020895. Accessed Oct 29, 2026.
- Drugs@FDA: REVATIO (sildenafil citrate), NDA 021845. Accessed Oct 29, 2026.
- Drugs@FDA: CIALIS (tadalafil), NDA 021368. Accessed Oct 29, 2026.
- Drugs@FDA: LEVITRA (vardenafil), NDA 021400. Accessed Oct 29, 2026.
- Drugs@FDA: STENDRA (avanafil), NDA 202276. Accessed Oct 29, 2026.
- Drugs@FDA: CAVERJECT (alprostadil), NDA 020379. Accessed Oct 29, 2026.
- Virag R. Intracavernous injection of papaverine for erectile failure. Lancet. 1982;2(8304):938. PMID 6126784. Accessed Oct 29, 2026.
- US Patent 6,469,012: Pyrazolopyrimidinones for the treatment of impotence (Pfizer). Accessed Oct 29, 2026.
- Teva: exclusive launch of generic Viagra tablets in the United States (Dec 11, 2017), SEC Form 6-K exhibit. Accessed Oct 29, 2026.
- NIDDK: treatment for ED. Accessed Oct 29, 2026.
- Mendoxa ED care (product, format, max 1 dose per 24 hours). Accessed Oct 29, 2026.
- Mendoxa ED intake: plan prices (term_options). Accessed Oct 29, 2026.
About Mendoxa
Mendoxa (mendoxa.co) is a US telehealth brand. Independent licensed providers (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).
- Prescription required. 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 (FDA compounding Q&A).
- 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.