Drug profile

The FDA adverse-event record for (S)-Methoprene/Fipronil

10 FDA reports name (S)-Methoprene/Fipronil, a lower-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#2642 of 2,679
by report volume (all drugs)
10
adverse-event reports
0.0%
death-coded share
Dog
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, (S)-Methoprene/Fipronil ranks #2536 of 2679 by total reports (10). Death-coded-share rank requires at least 50 reports. National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#2536
This drug, reports of 2679

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. (S)-Methoprene/Fipronil has 10 reports now versus 10 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
+0.0 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to (S)-Methoprene/Fipronil changes

Signature read: 10 reports place (S)-Methoprene/Fipronil in the lower third of FDA AER volume (#2642 of 2,679).

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
10
Total Reports
0
Deaths Reported
0.0%
Death-coded share of reports

Active Ingredients

(S)-Methoprene/Fipronil

Administration Routes

TopicalCutaneous

Species Affected

Dog 6
Cat 4

Most Affected Breeds

Domestic Shorthair 3
Spaniel - Cocker American 2
Boxer (German Boxer) 1
Pug 1
Shih Tzu 1
Domestic Mediumhair 1
Spaniel - King Charles Cavalier 1

Most Reported Reactions

Hyperactivity 4
Scratching 4
Excessive licking and/or grooming 4
Lack of efficacy - NOS 3
Lack of efficacy (ectoparasite) - flea 3
Injection site pain 1
Injection site irritation 1
INEFFECTIVE, OTHER DRUG(S) 1
Panting 1
Vomiting 1
Lethargy (see also Central nervous system depression in 'Neurological') 1
Emesis 1

Outcome Breakdown

Ongoing
9 (90.0%)
Recovered/Normal
1 (10.0%)

(S)-Methoprene/Fipronil: low death-coded share in the FDA AER row

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

What to do with this drug

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

openFDA Animal & Veterinary Adverse Events (FDA CVM) for (S)-Methoprene/Fipronil (#2642 of 2,679 by report volume); death-coded 0.0%. PlainBreed drug row · report volume stamp 10 · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →