Advantage II Flea Treatment for Dogs, 21-55 lbs, 6 Doses (6-mos. supply)

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About This Item

Details

  • Flea protection for dogs weighing 21 to 55 pounds, at least 7 weeks old.
  • Easy-to-apply monthly topical treatment.
  • Delivers total flea protection and kills adult fleas, flea larvae and flea eggs through contact.
  • Starts killing fleas the same day and keeps working for 30 days.
  • Fragrance-free formula is waterproof after 24 hours of application.

Ingredients

Instructions

Size

FAQ

Learn More About Advantage II From Our Team of Experts

Important Information

Fleas rise to the top of your pet's coat as they die, so consider it a triumph if you start seeing more fleas at first, after treating your pet. If you’re still seeing fleas after application, it may be because your pet has picked up new fleas from the environment, which may include other pets, surfaces and outdoor areas. It may take up to 30 days to break the entire flea life cycle. Additionally, you should also treat sources of new fleas (i.e., carpet, yard, etc.) to ensure complete flea control.

About Advantage II for Dogs

Get the Advantage Over Fleas

Advantage II topical flea treatment and prevention for dogs kills fleas on your dog within 12 hours, and it continues to protect for 30 days. It’s easier to use than hard-to-swallow pills—simply apply the convenient drops once a month. Best of all, Advantage II is available without a prescription.

How Advantage II for Dogs Works

The active ingredients in Advantage II for Dogs (imidacloprid and pyriproxyfen) spread over the skin and hair coat. Fleas are killed through contact, so they don’t have to bite your dog to die. Do not use on cats.

Flea Treatment and Prevention

Advantage II doesn't just treat fleas––it breaks the flea lifecycle to prevent reinfestation.

Reliable Flea Protection

These flea drops kill adult fleas, flea larvae, flea eggs, and chewing lice.

Same-Day Effectiveness

Advantage II kills fleas on dogs within 12 hours, and it continues to prevent reinfestations for four weeks.

No Prescription Needed

You don’t have to go to the vet to get quality flea protection for your dog—simply buy and apply.

Fragrance-Free

This flea topical formula is fragrance-free and waterproof 24 hours after application.

Frequently Asked Questions

Can I Use Advantage II on My Dog?

Advantage II is for dogs 7 weeks of age and older. The product comes in four sizes: Small Dog (3-10 lbs.), Medium Dog (11-20 lbs.), Large Dog (21-55 lbs.), and Extra Large Dog (over 55 lbs.). Choose the right size based on your dog’s weight. Not for use on cats.

How Do I Apply Advantage II?

Break the seal on the tube, then part the hair on your dog’s back between the shoulder blades to show the skin. Squeeze the tube to expel the entire contents directly onto the skin. The number of application spots will depend on the weight of your dog—see product label for detailed instructions.

The Advantage Family

Get the Advantage over fleas with complete flea protection for your pet, home, and yard. The Advantage family of products has everything you need for a complete flea treatment and prevention plan, including monthly topical treatments, pet shampoos and sprays, household sprays for carpets and crevices, and even a yard and premise spray. Just be sure to get the right product for each need and use only as directed.

Shop K9 Advantix II

Questions & Answers

8 Customer Questions


How long will this product protect my dogs if they are swimmers???

Answer by ChewyApr 03, 2018
This product is waterproof and swimming will not have any effect on it.

What are the inactive ingredients?

Answer by ChewyJun 08, 2023
This treatment has 94% based alcohol as an inactive ingredient.

will advantage II kill or repel mosquitoes?

Answer by ChewySep 08, 2022
This treatment does not repel mosquitoes.

Does this medicine kill ticks

Answer by ChewyMay 12, 2021
This treatment does not kill ticks.

4.4
Rated 4.4 out of 5 stars
635 Ratings

Customers Mention

Chewy identifies key considerations with the help of artificial intelligence and our veterinarians.

Ease of Use

76% Positive

Effectiveness

77% Positive

Ingredients

76% Positive

Long-Term Benefits

78% Positive

335 Customer Reviews



Always consult a veterinarian about your pet’s health needs. Customer reviews should not be used as medical advice.

Rated 1 out of 5 stars
By Michelle on Dec 19, 2025

Doesn’t work

I put the medication on Scotland as directed. While I didn’t expect it to work immediately, I also didn’t expect to see more fleas than we started with. I treated

I put the medication on Scotland as directed. While I didn’t expect it to work immediately, I also didn’t expect to see more fleas than we started with. I treated all the animals in my home as well as my carpets and washed their bedding. Nothing is helping.


Rated 3 out of 5 stars
By Peggy on Jan 17, 2026

Advantage II

Advantage II seems to have lost some of its efficacy against fleas in Seattle area, works for a couple of weeks though!

Advantage II seems to have lost some of its efficacy against fleas in Seattle area, works for a couple of weeks though!


Rated 1 out of 5 stars
By Nancy on Dec 2, 2025

Stopped working

My Vet said that the fleas in our area are minded to this treatment. He said I am wasting my money. I need to contact Chewy to see if I can return the unopened product

My Vet said that the fleas in our area are minded to this treatment. He said I am wasting my money. I need to contact Chewy to see if I can return the unopened product I just purchased.


Rated 5 out of 5 stars
By Belinda on Sep 26, 2025

Fleas be Gone

Wish I had been using Advantage II on Jax! Before using i didn't know how the fleas had chewed him up, I thought it was an allergy which he got shot and I bought

Wish I had been using Advantage II on Jax! Before using i didn't know how the fleas had chewed him up, I thought it was an allergy which he got shot and I bought so many tubes of anti-itch cream. bought a flea comb and so many fleas! Vet suggested Advantage, using now...none 1 or 2 fleas!! Jax doesn't scratch and scratch anymore and he can get some sleep and me too! I am so happy for him!


Rated 4 out of 5 stars
By Ann on Dec 30, 2025

This is an inexpensive way to prevent fleas but it stinks

I used it on my doodle but the smell was making me sick so I had to bath her. I am going to have to go back to pills.

I used it on my doodle but the smell was making me sick so I had to bath her. I am going to have to go back to pills.


Rated 1 out of 5 stars
By Angela on Sep 18, 2025

Doesn't work in far north

I used to use this brand hen i lived in the suburbs and it worked great for fleas and didn't notice ticks at all. Once we moved up north to more deep woods it didn't

I used to use this brand hen i lived in the suburbs and it worked great for fleas and didn't notice ticks at all. Once we moved up north to more deep woods it didn't seem to do much for ticks, we kept finding engorged ticks on the dog and several getting embedded.


Rated 5 out of 5 stars
By Amy on Sep 3, 2025

It works

Glad I decided to try switching from frontline to advantage. After months and months of treating for fleas, they are now gone. I was wasting my money on frontline

Glad I decided to try switching from frontline to advantage. After months and months of treating for fleas, they are now gone. I was wasting my money on frontline. It wasn’t working on my dogs or my cats.


Rated 4 out of 5 stars
By Zachary on Aug 8, 2025

The best flea med

I live in a rul area. Flea. And mosquito, along with ants, and spiders all invade my town. I've used a few competitors products and only advantage has worked every

I live in a rul area. Flea. And mosquito, along with ants, and spiders all invade my town. I've used a few competitors products and only advantage has worked every time. If I forget, or fleas aren't bad, through winter and I aply the med, sometimes takes about a week. But always works


Rated 5 out of 5 stars
By Chris on Jan 17, 2026

Works

I love this flea meds and the fleas dont!

I love this flea meds and the fleas dont!


Rated 5 out of 5 stars
By Catherine on Aug 25, 2025

It's worked well for many years.

I've tried a couple of other types of flea medicine on the advice of others, but Advantage works best, and unless the price goes up, I'll stay with it.

I've tried a couple of other types of flea medicine on the advice of others, but Advantage works best, and unless the price goes up, I'll stay with it.