Spironolactone vs Minoxidil: side effects in FDA adverse event reports
At a glance
| Spironolactone | Minoxidil | |
|---|---|---|
| Drug class | Aldosterone Antagonist | Arteriolar Vasodilator |
| Brand names | – | – |
| FAERS reports | 139,599 | 44,631 |
| Serious | 78% | 11% |
| Death outcome | 18,066 | 449 |
| Boxed warning | No | Yes Minoxidil tablets contain the powerful antihypertensive agent, minoxidil, which may produce serious adverse effects. It can cause pericardial effusion, occasion |
Signals both drugs share
No strong shared signal after removing coding and lab terms.
Labeled signals distinctive to Spironolactone
- Hyperkalaemia — n=5,027, PRR 25.1 Labeled adverse reaction
Labeled signals distinctive to Minoxidil
- Hair growth abnormal — n=656, PRR 49.1 Labeled (related wording)
- Hair disorder — n=324, PRR 19.0 Labeled (related wording)
- Hypertrichosis — n=295, PRR 88.3 Labeled adverse reaction
Common questions
Which has more reported side effects, Spironolactone or Minoxidil?
Spironolactone has 139,599 FAERS reports and Minoxidil 44,631. 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 (78% vs 11%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Spironolactone and Minoxidil share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Spironolactone or Minoxidil 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.