What is an insect growth regulator?

Insect growth regulators are common ingredients in many commercial insect prevention and treatment products, including flea products.

Insect growth regulators are common ingredients in many commercial insect prevention and treatment products, including flea products.

There are two main types of IGRs: Juvenile Hormones and Chitin Synthesis Inhibitors, PetMD explained. Among the most common of commercial products, juvenile hormones IGRs copy and take the place of actual hormones in an insect's body, stopping the insect's ability to molt into an adult. Also called an insect development inhibitor, chitin synthesis inhibitors stop the growth of chitin in an insect's exoskeleton, which effectively stops its ability to molt and grow as well. The chemicals in IGRs mimic only insect hormones, not mammals, so they won't affect your pup's growth and development. 

IGRs don't kill fleas. The stunted juveniles can survive the IGR, but they won't become adults or lay eggs. Because of this, they rarely affect the adult fleas on your pooch. The National Pesticide Information Center pointed out that IGRs may damage an adult flea's reproduction system and leave it sterile.

Whether you're dealing with an infestation or preventing one, you'll want a product with both IGRs and adulticide for mature fleas, such as Hartz® UltraGuard Pro® Flea and Tick Drops for Dogs and Puppies.


This content is provided by the flea treatment experts at Hartz®. We offer flea sprays, shampoos and drops to keep your pets safe inside and outside your home.