Pet Safety / Compounds / Nitenpyram

Is Nitenpyram safe for dogs and cats?

Low risk for pets

Nitenpyram (Capstar) has an outstanding veterinary safety record in dogs across all breed sizes. FDA-approved oral tablet; safe at label doses and at 10× label dose in safety studies. The rapid flea kill (30–60 min) makes it valuable for acute flea infestation control, pre-surgery flea clearing, and newly adopted shelter animals. Side effects are uncommon and typically mild (hypersalivation, rarely hyperexcitability from dying flea activity) and are transient. There is no environmental flea-repelling or residual protection — Capstar kills existing adult fleas only, requiring combination with a residual product for ongoing prevention.

What is nitenpyram?

The IUPAC name is (E)-1-N'-[(6-chloro-3-pyridinyl)methyl]-1-N'-ethyl-1-N-methyl-2-nitroethene-1,1-diamine.

Also known as: (E)-1-N'-[(6-chloro-3-pyridinyl)methyl]-1-N'-ethyl-1-N-methyl-2-nitroethene-1,1-diamine, (E)-Nitenpyram, Capstar, (E)-N-((6-Chloropyridin-3-yl)methyl)-N-ethyl-N'-methyl-2-nitroethene-1,1-diamine.

IUPAC name
(E)-1-N'-[(6-chloro-3-pyridinyl)methyl]-1-N'-ethyl-1-N-methyl-2-nitroethene-1,1-diamine
CAS number
150824-47-8
Molecular formula
C11H15ClN4O2
Molecular weight
270.71 g/mol
SMILES
CCN(CC1=CN=C(C=C1)Cl)C(=C[N+](=O)[O-])NC
PubChem CID
3034287

Risk for dogs

Low risk

Nitenpyram (Capstar) has an outstanding veterinary safety record in dogs across all breed sizes. FDA-approved oral tablet; safe at label doses and at 10× label dose in safety studies. The rapid flea kill (30–60 min) makes it valuable for acute flea infestation control, pre-surgery flea clearing, and newly adopted shelter animals. Side effects are uncommon and typically mild (hypersalivation, rarely hyperexcitability from dying flea activity) and are transient. There is no environmental flea-repelling or residual protection — Capstar kills existing adult fleas only, requiring combination with a residual product for ongoing prevention.

Risk for cats

Low risk

Nitenpyram is one of the few flea control compounds with an FDA approval specifically for cats, supported by clinical safety studies. It is particularly valued in cats because it avoids the pyrethroid class entirely — a benefit for owners concerned about pyrethroid cat toxicity. The longer half-life in cats (~7.7h vs. 2.8h in dogs) reflects the cat's reduced hepatic metabolism; clinical experience shows it is well-tolerated. Approved doses: 11.4 mg/cat (small tablets). Minor transient signs (increased scratching as fleas die and move) are common and expected.

Regulatory consensus

2 regulatory and scientific bodies have classified Nitenpyram. The classifications differ — that's the data.

AgencyYearClassificationNotes
US EPA—Toxicity Category III
WHO—Class III

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where pets encounter nitenpyram

  • Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational Environments — Factories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Nitenpyram:

  • Spinosad; Bt; Neem; Beneficial insects; Physical barriers
    Trade-offs: Species-specific; no chemical residues; self-sustaining once established; slow onset (weeks vs hours for chemicals); requires ecological knowledge; may not achieve complete control; compatible with organic certification.
    Relative cost: 1.2-2×

Frequently asked questions

Is nitenpyram safe for pets?

Nitenpyram (Capstar) has an outstanding veterinary safety record in dogs across all breed sizes. FDA-approved oral tablet; safe at label doses and at 10× label dose in safety studies. The rapid flea kill (30–60 min) makes it valuable for acute flea infestation control, pre-surgery flea clearing, and newly adopted shelter animals. Side effects are uncommon and typically mild (hypersalivation, rarely hyperexcitability from dying flea activity) and are transient. There is no environmental flea-repelling or residual protection — Capstar kills existing adult fleas only, requiring combination with a residual product for ongoing prevention.

What products contain nitenpyram?

Nitenpyram appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

See Nitenpyram in the pets app

Look up products containing nitenpyram, compare to alternatives, and explore the full data record.

Open in pets View raw API data

Sources (2)
  1. US EPA: Neonicotinoid Registration Review — imidacloprid, clothianidin, thiamethoxam, acetamiprid, dinotefuran; bee risk assessment; sublethal effects; colony-level modeling; pollinator exposure through pollen and nectar; aquatic invertebrate toxicity; registration review decision (2020) (2020) — regulatory
  2. ASPCA Animal Poison Control Center: Neonicotinoid Insecticide Toxicosis — imidacloprid, nitenpyram, dinotefuran; pet product safety (Advantage, Capstar, Vectra); nAChR mechanism; mammalian vs. insect selectivity; clinical signs and management (2023) (2023) — veterinary

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →