Drug side effects
sildenafil Side Effects
The reactions most often reported to the FDA for sildenafil (also sold as Viagra, Revatio), with demographics, serious outcomes, and reporting trends.
Data updated 2026-05-15
- 55,325
- FAERS reports
Data from the FDA Adverse Event Reporting System (FAERS), 2004 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.
The most commonly reported side effects of sildenafil come from 55,325 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.
This page analyzes 55,325 reports to the FDA Adverse Event Reporting System (FAERS) for sildenafil (Viagra): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.
Total Reports
55,325
Reports Mentioning Death
8,392
15.2% of reports — not proof the medicine caused the death
Hospitalizations
24,609
44.5% of reports
Top Indication
Pulmonary Arterial Hypertension
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 8,392 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 3,847 |
| DYSPNOEA | 1,119 |
| PULMONARY ARTERIAL HYPERTENSION | 739 |
| PULMONARY HYPERTENSION | 587 |
| PNEUMONIA | 530 |
| RIGHT VENTRICULAR FAILURE | 520 |
| CONDITION AGGRAVATED | 514 |
| RESPIRATORY FAILURE | 472 |
| CARDIAC FAILURE | 432 |
| DISEASE PROGRESSION | 428 |
| HYPOTENSION | 419 |
| DIARRHOEA | 403 |
| CARDIAC ARREST | 385 |
| HEADACHE | 366 |
| NAUSEA | 339 |
| FATIGUE | 328 |
| FLUID RETENTION | 315 |
| OXYGEN SATURATION DECREASED | 305 |
| HYPOXIA | 277 |
| MALAISE | 269 |
Reactions in Hospitalization Reports
Top reactions in 24,609 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| DYSPNOEA | 4,962 |
| HEADACHE | 2,343 |
| PNEUMONIA | 2,313 |
| DIARRHOEA | 2,176 |
| NAUSEA | 1,955 |
| FATIGUE | 1,669 |
| HYPOTENSION | 1,579 |
| FLUID RETENTION | 1,540 |
| DIZZINESS | 1,456 |
| PULMONARY ARTERIAL HYPERTENSION | 1,395 |
| VOMITING | 1,391 |
| DEATH | 1,288 |
| COUGH | 1,240 |
| OXYGEN SATURATION DECREASED | 1,188 |
| CONDITION AGGRAVATED | 1,159 |
| MALAISE | 1,143 |
| CHEST PAIN | 1,141 |
| PULMONARY HYPERTENSION | 1,141 |
| HOSPITALISATION | 1,126 |
| FALL | 1,102 |
Nearby, Related Medications
What the FAERS Data Reveals About sildenafil Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 55,325 voluntary reports linked to sildenafil and its brand equivalents (Viagra, Revatio), spanning 2004 through 2025. Of those, 8,392 (15.2%) listed death as an outcome and 24,609 (44.5%) involved hospitalization. The most common indication reported alongside adverse events was Pulmonary Arterial Hypertension.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 56% were female and 44% male; age distribution skews toward 45-64, with 14,106 reports in that bracket. The single most reported reaction is dyspnoea with 7,729 submissions, followed by headache and diarrhoea.
How to read these numbers
FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.
Drugs With a Similar FAERS Report Volume
Other medications with a total FDA adverse-event report count closest to sildenafil's 55,325.
Read our methodology - how this data is sourced, computed, and verified.