Major Uses

Fipronil, methoprene, and cyphenothrin is a combination flea and tick control product that kills existing fleas and ticks and helps prevent new infestations for a full month following application. It works rapidly and is for use on dogs 12 weeks of age and older. The product is also beneficial in the control of chewing lice, mosquitoes, and mites.

Fipronil, methoprene, and cyphenothrin, when used properly, can significantly reduce the risk of numerous potentially serious diseases and conditions, including Lyme disease, Rocky Mountain spotted fever, dermatitis associated with flea bite allergy, ehrlichiosis, babesiosis, anaplasmosis, tularemia, bartonellosis, and tapeworms.

Common Precautions

The most common side effect associated with use of fipronil, methoprene, and cyphenothrin is irritation at the site of application. This irritation is almost always temporary and should disappear within a few days of application. Severe irritation is helped by bathing the animal with mild soap and rinsing well. Ingestion of the product may cause excessive salivation and foaming at the mouth. Other side effects are possible, but very rare.

Fipronil, methoprene, and cyphenothrin should not be used on animals less than 12 weeks of age or under 4 pounds. The product is for external use only. Caution is needed when using on pregnant, nursing, debilitated, aged, or sensitive dogs. Fipronil, methoprene, and cyphenothrin is not for use on cats. A similar but different product exists for cats. The two should not be confused. Fipronil, methoprene, and cyphenothrin should not be used on dogs that are groomed by cats.

Fipronil, methoprene, and cyphenothrin may interact with other medications and supplements, including other flea and tick control products. It is important to disclose all medical history before beginning treatment with any flea and tick control product.

Fipronil, methoprene, and cyphenothrin should not be used in animals with a known allergy or hypersensitivity to the drug. An overdose of fipronil, methoprene, and cyphenothrin is dangerous and should be considered an emergency. Any known or suspected overdose should be reported to a veterinarian right away.


Fipronil, methoprene, and cyphenothrin should be stored in the original packaging, at room temperature, and away from children and animals.


Fipronil, methoprene, and cyphenothrin as a combination product is available in applicator tubes of various strengths. Fipronil, methoprene, and cyphenothrin should be applied between the shoulder blades. Dogs weighing 4 to 22 lbs should receive one 0.67 ml applicator once monthly. Dogs weighing 23 to 44 lbs need treatment with one 1.34 ml applicator, while dogs weighing 45 to 88 lbs need one applicator containing 4.02 ml once monthly. Very large dogs weighing 89 to 132 pounds need one 4.02 ml applicator monthly.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

The product is for once monthly dosing. If a dose of fipronil, methoprene, and cyphenothrin is missed, it should be applied as soon as possible. Two doses of this medication should not be applied at once or in any 30-day period.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.