Frontline Plus Vs. PetArmor Plus

By Landon Easton •  Updated: 02/23/21 •  7 min read

Protect your furry friends and make them the happiest fur-babies with the best flea and tick treatments.

Your doggos and cats deserve the best care through the use of effective and safe treatment solutions, and if they are struggling with fleas or pets because they just had to make new friends or roll around in the park, you need to ensure that the treatment options you choose work well. In your search for the best treatment for your pets, Frontline Plus and Pet Armor Plus will come off as the top-recommended remedies. But how do you pick one over the other? Are these two treatments as effective as others claim them to be, and which of the two will offer fast but long-lasting relief?

To help you make a more informed choice/ decision, this article takes a look at some of the differences between Frontline Plus and PetArmor Plus.

Frontline Plus and PetArmor Plus – Comparison Table

Frontline Plus Vs. PetArmor Plus Frontline Plus PetArmor Plus
Active Ingredients Fipronil




Effectiveness 4 hours 24 hours
Application Ready-to-use Pipetted topical application Ready-to-use Pipetted topical application
Ease of use Cap comes off easily Cap needs to be cut off with scissors
Mode of action Kills adult fleas, and destroys larvae and eggs Kills adult fleas, and destroys larvae and eggs

Frontline Plus and PetArmor Plus – Overview

Frontline Plus is a top-rated, licensed product that’s designed for use and efficient treatment and prevention of flea infestations and tick bites. It comes in pre-measured pipettes that ensure easy applications, especially for the parts of the hair at the back of the pup’s ears, necks, and in between the shoulder blades.

It comes formulated with highly effective active ingredients Fipronil and S-Methoprene that not only kill fleas and ticks on contact but also prevent re-infestation by breaking the fleas’ re-infestation lifecycles.

PetArmor Plus is the other effective topical parasite treatment formulation that protects your pets from ticks, fleas, and even chewing lice. It promises effective pest protection for a maximum of 1 month, and you may also like it because it’s waterproof, meaning it will stick on the pets’ skin/ coat for a long time.

This topical preventative parasite treatment comes pre-dosed in pipettes so that you’d only have to snap off the tops of the pipettes, squeezing its contents into the areas of the skin between and behind the ears, neck, and shoulder blades.

Like Frontline Plus, PetArmor is formulated using Fipronil and S-Methoprene, which work by killing not only the adult bugs, but also the flea eggs and larvae. By targeting the entire lifecycles of the fleas, while providing lasting protection of up to 30 days, this treatment is one of the best treatment options for your pets.

Frontline Plus and PetArmor Plus – How Do They Compare?

To give you a more comprehensive overview of these two pest treatments and how they differ, we’ll take a look at the main features that differentiate these pesticides.

Both PetArmor Plus and Frontline Plus come formulated with equal concentrations of fipronil and (S)-Methoprene. What this means is that there are no differences in their levels efficiency levels. The only difference between these two pesticides is that while Frontline Plus works almost instantly, PetArmor Plus takes a little longer to work, with its maximum efficiency reported to be a maximum of 24 hours.

As mentioned above, both of these pesticides contain Fipronil and S-Methoprene, the two ingredients that make these treatments two very effective flea, tick, and lice killers. How do they work?

Well, FIpronil is a nerve agent that attacks the nervous system of the adult fleas and tick, paralyzing them and eventually causing the death of the bugs.

(S)-Methoprene, on the other hand, works by preventing the eggs and larvae of the fleas and ticks from maturing and developing into the next stage in their lives, disrupting and subsequently destroying the bugs’ lifecycle. By doing this, this ingredient also prevents re-infestations.

With that in mind, it would be a great idea to buy either pesticide treatment if you are worried about re-infestation, especially the fleas seem to have spread to most parts of your home.

These two pesticides come with easy-to-use applications, and you won’t have to struggle with pills in treats because both treatments are spot-on formulations that come pre-dosed in small pipettes. You’ll need to squeeze the contents of the pipette onto the target area of the skin.

That said, the only difference in application between this treatment is that you’ll need to use a pair of scissors to cut off the top of PetArmor Plus, while Frontline Plus’ cap is opened by snapping off the top.

Note that you’d have to apply these treatments monthly.

Frontline Plus starts working within a 4-hour period after its application, and it will start to kill the adult fleas in this short period. What this means is that you should expect to see the fleas climbing out of your pooch’s fur in 24 hours or less. This is a great sign because the fleas climb from towards the top of your pet’s hair shafts, moving away from the skin just before they die.

This is the case because the liquid applied is absorbed into the skin of your pet, where it accumulates in their hair follicles, and it’s released slowly throughout your pet’s body for a period of 30 days. During this time, Frontline Plus kills the adult ticks and fleas while also breaking the re-infestation cycle by affecting the development of larvae and the full development of the eggs.

While PetArmor Plus contains the same ingredients as Frontline Plus, PetArmor Plus starts to work within 24 hours of its application. During this time, the fleas start to die, and you should expect to see multiple fleas rising to the surface and the end of your pet’s fur, as is expected from the fleas when they are about to die.

All products meant to help tend to come with risks, and when it comes to topical products, the risk of skin reactions is always there.

You will be happy to know that there haven’t been adverse reactions reported from the use of Frontline Plus, and if they occur, the reactions are often short-lived and mild, meaning that your pooch may have some mild itching and redness on the application site. This will, however, resolve in 24 hours. This is also the case with PetArmor Plus, and you can only expect transient and mild reactions, albeit rarely.

Both products are toxic to kitties, meaning you should put away your pups from the kitties for at least 24 hours after the use of either treatment.

Frontline Plus vs. PetArmor Plus – Which is better?

Both pesticides are formulated with Fipronil and (S)-methoprene which work to eliminate adult fleas, as well as the eggs and the larvae. And though they are both effective, Frontline Plus works a lot faster, with the fleas starting to die in 4 hours, unlike the 24-hour period for PetArmor. Since most of us would be looking for a remedy that works fast, Frontline Plus easily takes the top spot.

But if you are constrained by your budget, PetArmor would then be a preferable option, albeit with the 20-hour difference in effective times.


Is Fipronil safe for use on cats?

Yes, acccording to EPA’s determination, Fipronil is safe for use on cats and dogs, and it won’t harm human who handle it.

Can I use Frontline Plus or PetArmor Plus on pregnant or nursing dogs with fleas?

You Can use Frontline Plus on pregnant or nursing bitches, but if you opt for PetArmor Plus, you may want to consul the veterinarian first.

Landon Easton

Landon is a veteran in the Pest Control industry, with over 15 years of experience and has helped thousands of homeowners. He started Your Pest Guide in 2020 as a way to help spread his knowledge to the general public, so they can get rid of all of their creepy-crawlies in their homes without spending an arm and a leg.