There are essentially three ways in which you can use Insect Growth Regulators to prevent fleas.

Talk to your vet about treating your pet with an insect growth regulator that is given to your pet monthly in their food (or for cats, as a six monthly injection). If fleas land on a treated pet, they'll be unable to reproduce, and therefore unable to start an infestation at home.
 

Remember that in common with all flea treatments applied or given to a pet, every cat and dog in the house must be treated.

Insect growth regulators are also contained in a very limited number of veterinary 'spot-on' products. However, spot-on products can be rendered less effective than oral and injectable treatments if the animal is subsequently washed or gets caught out in the rain.
 

Also, because these treatments contain conventional insecticides as well as insect growth regulators, it is necessary to make sure that you and your family don't touch the pet for some time following application. No such precautions are necessary when using the oral or injectable method of flea control.
 

Again, with any spot-on product, all cats and dogs in the house must be treated simultaneously.

If you have a large number of cats and dogs, and it is simply too expensive to treat each individual animal, then use a household spray that contains an insect growth regulator. This is a much less precise way of dealing with the problem, as it is relatively easy to miss areas where fleas might congregate. With a little luck, though, it'll prevent a major outbreak.

Insect Growth Regulators are very effective at preventing household flea infestations, particularly when given to the pet orally or by injection. However, they do this not by killing fleas, but by preventing them reproducing.
 

So regardless of which of the above methods you use, there is always a chance that you may see a few fresh fleas that your cat or dog has picked up round at the neighbour's. These are called 'hitchhiker fleas'.
 

Provided that you are using an insect growth regulator, these hitchhikers won't be able to start an infestation in your home. In all likelihood, they'll be caught in such small numbers that you'll never even see them.
 

But if you do, and you want to remove them faster than they will die of natural causes, then try CAPSTAR.
 

CAPSTAR has been specifically designed for the rapid removal of adult fleas from a pet. In fact, it starts working in as little as 15 minutes. And unlike conventional insecticides that are applied to the animal (such as spot-on or spray products), CAPSTAR is given to your pet as a tablet. So there are no insecticidal residues that can rub off on you or your family.
 

CAPSTAR is also ideal for use alongside an Insect Growth Regulator if your pet has been diagnosed with Flea Allergic Dermatitis. In this case, it's especially important to remove fleas in the fastest possible time. So use an insect growth regulator to prevent a household infestation, and CAPSTAR immediately when and, more importantly, if fleas are seen on your pet.