Table of Contents
How do Insect Growth Regulators work?
Why is it important to have a flea spray with an IGR?
Is an IGR strong enough on it's own to kill fleas?
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What is an Insect Growth Regulator? An expert guide to killing fleas
- By Leigha
-
- January 5, 2026
- 1 MIN READ
Insect growth regulators (IGRs) are a specialised class of pest control products designed to disrupt the development of insects rather than killing them instantly. Widely used in flea killing products, IGRs offer a targeted and environmentally considerate approach to flea control and prevention.
How do Insect Growth Regulators work?
Unlike conventional insecticides that attack the nervous system, IGRs interfere with a flea's life cycle. They prevent early fleas from reaching maturity or reproducing, which gradually reduces populations over time. IGRs typically work in one of two ways:
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Juvenile hormone analogues mimic natural insect hormones, keeping fleas in an immature state so they cannot develop into reproductive adults.
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Chitin synthesis inhibitors block the formation of chitin, an essential component of an insect’s exoskeleton, causing death during moulting.
Why is it important to have a flea spray with an IGR?
One of the main advantages of insect growth regulators is their selectivity. They are designed to affect insects only and have very low toxicity to humans, pets, birds, and most beneficial wildlife when used correctly. This makes them perfect for sensitive environments like your home, schools or animal housing.
IGRs also play an important role in preventing fleas from coming back. By breaking the flea life cycle, they reduce reliance on traditional insecticides and help slow the development of flea resistance.
Is an IGR strong enough on it's own to kill fleas?
No. IGRs do not provide an immediate knockdown of adult insects. So they need to be used alongside adulticides to control existing infestations while preventing future generations, like Itch Flea House Spray for Homes which includes all the flea killing ingredients you need to stop a flea infestation in your home.
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