Drug side effects
phenelzine Side Effects
The reactions most often reported to the FDA for phenelzine (also sold as Nardil), with demographics, serious outcomes, and reporting trends.
Data updated 2026-05-15
- 1,551
- 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 phenelzine come from 1,551 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.
This page analyzes 1,551 reports to the FDA Adverse Event Reporting System (FAERS) for phenelzine (Nardil): 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
1,551
Reports Mentioning Death
41
2.6% of reports — not proof the medicine caused the death
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 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 depression with 187 submissions, followed by headache and anxiety.
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 phenelzine's 1,551.
Read our methodology - how this data is sourced, computed, and verified.