Spironolactone vs Finasteride: side effects in FDA adverse event reports
At a glance
| Spironolactone | Finasteride | |
|---|---|---|
| Drug class | Aldosterone Antagonist | 5-alpha Reductase Inhibitor |
| Brand names | – | – |
| FAERS reports | 139,599 | 59,947 |
| Serious | 78% | 65% |
| Death outcome | 18,066 | 5,092 |
| Boxed warning | No | No |
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 Finasteride
- Erectile dysfunction — n=4,195, PRR 68.0 Labeled adverse reaction
- Sexual dysfunction — n=2,398, PRR 90.4 Labeled adverse reaction
- Ejaculation disorder — n=697, PRR 112.7 Labeled adverse reaction
- Testicular pain — n=692, PRR 97.8 Labeled adverse reaction
- Organic erectile dysfunction — n=241, PRR 453.0 Labeled (related wording)
- Testicular disorder — n=159, PRR 64.8 Labeled (related wording)
- Orgasm abnormal — n=120, PRR 61.0 Labeled (related wording)
- Male sexual dysfunction — n=98, PRR 69.9 Labeled (related wording)
Common questions
Which has more reported side effects, Spironolactone or Finasteride?
Spironolactone has 139,599 FAERS reports and Finasteride 59,947. 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 65%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Spironolactone and Finasteride share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Spironolactone or Finasteride 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.