Aspirin vs Acetaminophen: side effects in FDA adverse event reports
At a glance
| Aspirin | Acetaminophen | |
|---|---|---|
| Drug class | Nonsteroidal Anti-inflammatory Drug, Platelet Aggregation Inhibitor | – |
| Brand names | Cardiaspirin Protect | – |
| FAERS reports | 533,828 | 444,741 |
| Serious | 71% | 72% |
| Death outcome | 48,985 | 62,469 |
| Boxed warning | No | Yes RISK OF MEDICATION ERRORS AND HEPATOTOXICITY Take care when prescribing, preparing, and administering acetaminophen injection to avoid dosing errors which could |
Signals both drugs share
| Reaction | Aspirin | Acetaminophen | Label screen (A / B) |
|---|---|---|---|
| Hyperparathyroidism secondary | 760 · PRR 16.5 | 543 · PRR 12.6 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Aspirin
- None stood out among the strongest labeled signals.
Labeled signals distinctive to Acetaminophen
- Glossodynia — n=5,431, PRR 14.9 Labeled (related wording)
- Muscle injury — n=3,986, PRR 44.1 Labeled (related wording)
- Acute hepatic failure — n=3,176, PRR 14.1 Labeled (related wording)
- Sleep disorder due to general medical condition, insomnia type — n=2,974, PRR 40.0 Labeled (related wording)
- Peripheral venous disease — n=1,405, PRR 25.2 Labeled (related wording)
- Infusion site pruritus — n=670, PRR 12.7 Labeled (related wording)
- Infusion site discharge — n=465, PRR 17.3 Labeled (related wording)
Common questions
Which has more reported side effects, Aspirin or Acetaminophen?
Aspirin has 533,828 FAERS reports and Acetaminophen 444,741. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (71% vs 72%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Aspirin and Acetaminophen share?
Both drugs carry disproportionality signals for hyperparathyroidism secondary. Shared signals often reflect a shared drug class or the condition both are used for.
Is Aspirin or Acetaminophen safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.