Home > Family & Pets > Flea Control > Advantage II for Cats

Advantage II for Cats Review

By: Carl Laron on May 12, 2017

Bottom Line

Advantage II for Cats gets consistently high ratings from both vets and cat owners. Though it doesn't work for every cat, it's more reliably effective than any other product. One monthly dose, applied to the back of the cat's neck, kills adult fleas as well as eggs and larvae.


  • Kills adult fleas, eggs and larvae
  • Highly effective
  • Side effects are rare
  • No prescription required


  • Leaves greasy residue
Our Analysis
Read Amazon Reviews

Breaking it down


Beats the competition. Advantage II for cats contains two key ingredients: imidacloprid, which kills adult fleas, and pyriproxyfen, which stops the growth of flea eggs and larvae. Vets describe Advantage II for Cats as very effective, and most owners agree. Many reviews on pet-product websites specifically note that this product worked when its leading competitor, Frontline Plus for Cats (Est. $40 for a three month supply), failed. However, some owners complain that Advantage II didn't work for their cats or that its effects wore off before the month was out. A few owners say that for them, the original version of Advantage (without pyriproxyfen) works better.


Few problems, but some can be serious. Vets describe Advantage II for cats as a very safe product. Most reviews from cat owners say that this flea control works without causing any side effects; a few even note that it is the only product their pets can tolerate without an adverse reaction. However, we saw a few reports at Amazon.com from owners whose cats suffered side effects -- some serious -- after use. While these problems appear to be extremely rare, it's probably wise to watch your cat closely after using Advantage II and be ready to call the vet if necessary.

Ease of use

No muss, slight fuss. Advantage II comes in single-dose tubes. To apply it, you part the fur at the back of the cat's neck and squeeze out the entire contents of the tube onto the skin. It needs to be applied in a spot the cat can't lick, as ingesting it can cause excessive drooling and hyperactivity. Most owners find Advantage II very easy to apply, although some cats may put up a struggle. The product may leave a greasy spot on the back of the neck; some owners say this dries quickly, while others say it stays wet for days and rubs off on the owner's hands. Most owners don't find the smell bothersome.

Our Sources

Contributors to Amazon.com, As of May 2017

Advantage II for Cats in its various strengths and dosages receives nearly 6,400 user reviews here, earning 4.3 stars out of 5, with additional reviews at Amazon.com spread across multiple pages. Most cat owners say they find this product effective, fast-working and easy to apply. However, some say it didn't work, and a few complain of dangerous side effects.

Contributors to 1800PetMeds.com, As of May 2017

There are more than 2,850 user reviews of Advantage II at this online pet pharmacy, covering both the dog and cat versions of the product. Users give it 4.2 stars out of 5 overall, with 4.2 stars for effectiveness. Comments are helpful, though less detailed than what we see at Amazon.com.

Contributors to Petco.com, As of May 2017

We found around 630 reviews of Advantage II for Cats at Petco.com. Its overall rating is 4.6 stars out of 5. Though a small handful describe the product as ineffective, most say that it works well and with fewer adverse reactions than with other treatments.

Staff of All Feline Hospital, Not Dated

Vets at the All Feline Hospital in Lincoln, Neb., list Advantage II for Cats among the best flea treatments available without a prescription. They say the product is "very safe and effective."

Jon Plant, DVM, DACVD, May 3, 2015

Veterinarian Jon Plant, a board-certified veterinarian dermatologist that runs the SkinVet clinic in Oregon, notes that Advantage II and other products in the line is "generally very effective," though he says that best results are achieved when the product is used monthly. He does cite a study, however, that notes that effectiveness in cats dropped toward the end of the month.

Editors of SimpleSteps.org, Not Dated

This directory from the Natural Resources Defense Council gives Advantage II a safety rating of two "paws" out of three, or medium risk. The key ingredient, imidacloprid, is of some concern, but editors note that the way it works reduces its toxic effects in humans and that it is listed as a "least toxic" and "reduced-risk" pesticide by various authorities. The IGR, pyriproxyfen, "has very little toxic effect on humans".

Recently Updated
Flea Control buying guide

What every best Flea Control has:

  • Works quickly and reliably.
  • Kills adult fleas, eggs and larvae.
  • Causes few side effects.

Read More »

Learn More »