phenelzine Side Effects
Also known as: Nardil
Analysis of 1,551 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
1,551
Death-Related
41
2.6% of reports
Hospitalizations
325
21.0% of reports
Top Indication
Depression
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 41 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 9 |
| COMPLETED SUICIDE | 7 |
| CONTRAINDICATED PRODUCT ADMINISTERED | 7 |
| DRUG DOSE TITRATION NOT PERFORMED | 6 |
| HAEMORRHAGE INTRACRANIAL | 6 |
| HYPERTENSIVE CRISIS | 6 |
| PRODUCT PRESCRIBING ERROR | 6 |
| POTENTIATING DRUG INTERACTION | 5 |
| DRUG INTERACTION | 4 |
| HAEMORRHAGE | 3 |
| SEROTONIN SYNDROME | 3 |
| ADVERSE DRUG REACTION | 2 |
| AGITATION | 2 |
| COMA | 2 |
| CONDITION AGGRAVATED | 2 |
| CONFUSIONAL STATE | 2 |
| DIARRHOEA | 2 |
| HYPERHIDROSIS | 2 |
| HYPOTENSION | 2 |
| MEDICATION ERROR | 2 |
Reactions in Hospitalization Reports
Top reactions in 325 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| DEPRESSION | 54 |
| DRUG INEFFECTIVE | 51 |
| DRUG INTERACTION | 43 |
| ANXIETY | 42 |
| HEADACHE | 34 |
| PHARMACEUTICAL PRODUCT COMPLAINT | 30 |
| INSOMNIA | 29 |
| MALAISE | 28 |
| DIZZINESS | 26 |
| FALL | 25 |
| CONFUSIONAL STATE | 24 |
| HYPERTENSION | 24 |
| SEROTONIN SYNDROME | 24 |
| FATIGUE | 22 |
| HYPOTENSION | 22 |
| WEIGHT DECREASED | 22 |
| FEELING ABNORMAL | 20 |
| SUICIDAL IDEATION | 19 |
| SOMNOLENCE | 18 |
| WEIGHT INCREASED | 18 |
Nearby — Related Medications
What the FAERS Data Reveals About phenelzine Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 1,551 voluntary reports linked to phenelzine and its brand equivalents (Nardil), spanning 2004 through 2025. Of those, 41 (2.6%) listed death as an outcome and 325 (21.0%) involved hospitalization. The most common indication reported alongside adverse events was Depression.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 61% were female and 38% male; age distribution skews toward 45-64, with 352 reports in that bracket. The single most reported reaction is drug ineffective with 330 submissions, followed by depression and headache.
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.