Revolution for Cats: Keep Fleas and Other Pests Away

Whether your cat lives exclusively indoors or has outdoor adventures, you want to protect them from harmful parasites. Revolution (selamectin) is one option to prevent fleas and other parasites in cats. 

Learn what Revolution is, how it works, how it’s given to cats, and more. 

Revolution for cats at a glance

What is Revolution for cats, and how does it work?

Revolution prevents internal and external parasites in cats. It’s FDA approved to kill adult fleas, prevent flea eggs from hatching, and prevent and control flea infestations. It requires a prescription from a veterinarian.

Revolution is also approved to:

• Prevent heartworm disease

• Treat and control ear mites

• Treat hookworm and roundworm

The main active ingredient in Revolution is selamectin, which is a type of avermectin medication. It’s similar to other well-known parasite prevention medications like ivermectin and milbemycin. 

Selamectin paralyzes the muscles of parasites, which eventually kills them. The medication doesn’t affect a cat’s muscles, which makes it a safe and effective way to control internal and external parasites.

How is Revolution dosed and given to cats?

Revolution is given to cats as a topical treatment, meaning it’s applied to the skin. It comes in single-dose tubes for easy administration. You must apply the medication to your cat once a month in order to prevent fleas and pests. 

Your veterinarian will prescribe the correct Revolution dosage for your cat. In general, this will be based on your cat’s weight:

• Cats up to 5 lbs: 15 mg (mauve packaging)

• Cats 5.1–15 lbs: 45 mg (blue packaging)

• Cats  15.1–22 lbs: 60 mg (taupe packaging)

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Do not apply Revolution to cats who are less than 8 weeks old. 

How to apply Revolution for cats

Here’s how to apply Revolution to your cat: 

1. Use the underside of the cap to break the seal.

2. Part the hair on the back of your cat’s neck.

3. Squeeze the entire contents of the tube onto your cat's skin.

4. Throw the tube in the trash.

After you apply the medication, it is absorbed from the skin into the bloodstream. It will begin working within 4 to 8 hours to kill parasites and reach full strength within a week. 

To make sure the medication is applied safely and absorbed correctly: 

• Don’t rub the medication in.

• Avoid petting the area where the medication was applied for 24 hours.

• Don’t bathe your cat for 24 hours after applying the medication.

• Either wear gloves when you apply the medication or wash your hands after applying it. 

• Don’t use Revolution near an open flame. It’s flammable until it is absorbed. 

What are the common side effects of Revolution in cats?

In general, Revolution is safe for most cats, and side effects are uncommon. The most common side effect is hair loss at the application site, but this is rare. If a cat licks the medication off, it can cause drooling.

What are the most serious risks of Revolution for cats?

The most serious side effects may occur in cats that are allergic to avermectin medications, including selamectin. An allergic reaction is rare, but if it occurs, symptoms include:

• Vomiting

• Diarrhea

• Itching

• Red skin

• Lethargy

• Weakness

• Drooling that doesn’t stop

• Difficulty breathing

• Muscle tremors

• Seizures

If you see any of these symptoms after you apply Revolution to your cat, immediately call your local veterinarian, a veterinary emergency clinic, or a pet poison hotline for advice.

Revolution is considered a long-acting medication. It can stay active in a cat’s system for 4 to 6 weeks or even longer in cats that have kidney or liver disease. 

Use Revolution with caution in any cats that are sick, medically fragile, or underweight. You should also use Revolution cautiously in cats that have not been tested for heartworm disease. 

Let your veterinarian know if your cat has any medical conditions or possible medication sensitivities before your cat is prescribed Revolution. 

Does Revolution interact with any other cat medications?

The active ingredient in Revolution, selamectin, does not seem to interact with any other cat medications. In testing the medication, pets were able to safely take Revolution at the same time as many other types of medications.

Still, let your veterinarian know about any medications, vitamins, or supplements your cat takes before it is prescribed Revolution. 

What should you do if your cat misses a dose of Revolution?

If you forget to give a dose of Revolution to your cat, give the next dose as soon as you remember. Then begin a new monthly dosing schedule starting from the day that you apply the medication. 

For example, if you forgot to give your cat their Revolution dose on the first of the month but instead gave it on the fifth, then give it on the fifth of each month moving forward. Do not give your cat a double dose of Revolution to catch up.

Why trust our experts?

Written by:

Sarah J. Wooten, DVM, CVJ

Dr. Sarah Wooten, DVM, CVJ, is a well-known international influencer in the veterinary and animal healthcare spaces. She has 16 years of experience in private practice and more than 15 years experience in veterinary media work.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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