phenylephrine Side Effects
Also known as: Neo-Synephrine
Analysis of 3,669 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
3,669
Death-Related
1,539
41.9% of reports
Hospitalizations
1,983
54.0% of reports
Top Indication
Product Used For Unknown Indication
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 1,539 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| OFF LABEL USE | 811 |
| FOLLICULITIS | 642 |
| HYPOAESTHESIA | 641 |
| TYPE 2 DIABETES MELLITUS | 641 |
| PEMPHIGUS | 626 |
| SYNOVITIS | 625 |
| SYSTEMIC LUPUS ERYTHEMATOSUS | 622 |
| INFUSION RELATED REACTION | 609 |
| WOUND | 600 |
| GLOSSODYNIA | 598 |
| CONDITION AGGRAVATED | 596 |
| MATERNAL EXPOSURE DURING PREGNANCY | 593 |
| PSORIATIC ARTHROPATHY | 593 |
| RHEUMATOID ARTHRITIS | 592 |
| GENERAL PHYSICAL HEALTH DETERIORATION | 583 |
| PNEUMONIA | 576 |
| WEIGHT INCREASED | 572 |
| MOBILITY DECREASED | 568 |
| INTENTIONAL PRODUCT USE ISSUE | 566 |
| PAIN | 565 |
Reactions in Hospitalization Reports
Top reactions in 1,983 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| OFF LABEL USE | 895 |
| CONDITION AGGRAVATED | 672 |
| PAIN | 653 |
| MOBILITY DECREASED | 650 |
| JOINT SWELLING | 649 |
| FOLLICULITIS | 634 |
| HYPOAESTHESIA | 630 |
| SYNOVITIS | 619 |
| TYPE 2 DIABETES MELLITUS | 619 |
| WOUND | 617 |
| ARTHROPATHY | 608 |
| PEMPHIGUS | 608 |
| SYSTEMIC LUPUS ERYTHEMATOSUS | 602 |
| RHEUMATOID ARTHRITIS | 599 |
| INFUSION RELATED REACTION | 595 |
| ARTHRALGIA | 591 |
| WEIGHT INCREASED | 591 |
| PNEUMONIA | 589 |
| PAIN IN EXTREMITY | 585 |
| GLOSSODYNIA | 583 |
Nearby — Related Medications
What the FAERS Data Reveals About phenylephrine Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 3,669 voluntary reports linked to phenylephrine and its brand equivalents (Neo-Synephrine), spanning 2004 through 2025. Of those, 1,539 (41.9%) listed death as an outcome and 1,983 (54.0%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 83% were female and 17% male; age distribution skews toward 18-44, with 1,351 reports in that bracket. The single most reported reaction is off label use with 1,210 submissions, followed by pemphigus and joint swelling.
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.
Read our methodology — how this data is sourced, computed, and verified.