Advantage II for Cats Dosage

advantage 2 for cats box


Advantage II for cats is available in three products, each corresponding to specific weight ranges. There is one for kittens (2 to 5 lbs), small cats (5 to 9 lbs), and large cats (over 9 lbs). The dosage is higher for heavier cats. See the dosage by weight chart below. The active ingredient concentration is the same in all three products. View the full product label for application information.

Related page: Generic Advantage II for Cats has the same active ingredients at less than half the cost.


Advantage II for Cats
Dosage by Weight

Cat Weight Monthly Dose
2 to 5 lbs 0.23 mL (0.0078 fl oz)
5 to 9 lbs 0.4 mL (0.014 fl oz)
over 9 lbs 0.8 mL (0.027 fl oz)

Advantage II for Cats
Product Information Chart

Cat Age 8 weeks or older
Cat Weight see chart above
Monthly Dose see chart above
Kills adults, eggs & larvae
Dose Duration 30 days
Ingredients 9.1% imidacloprid
0.46% pyriproxyfen
90.44% other ingredients
Product Label view
MSDS view
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Apply the Correct Dosage

Advantage II flea drops are specifically formulated and tested for cats of certain weights. The full dose of the correct product needs to be administered on a monthly basis. The product can fail if the manufacturer’s instructions aren’t followed. It’s not uncommon for owners to under-dose their pets as a result of splitting treatments between animals. Toxicity concerns can also result in under-dosing.

Re-dosing Early

Do not apply more than one tube per treatment. Under normal conditions, one dose will last a month. However, in severe infestations, it may be necessary to retreat the cat earlier in order to establish control. For kittens (2-5 lbs.), retreatment shouldn’t be done more often than once every 14 days. For small cats (5-9 lbs.) and large cats (over 9 lbs.), do not retreat more than once every 7 days. Once flea control is attained, the monthly re-treatment schedule should be adhered to.


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  • Nancy Keith August 19, 2016, 6:01 pm

    I have two cats, aged 4 months and weighing about 5+ pounds. I have 2 packets of Advantage II for small cat. My question is, these cats play together often; I should keep them apart until there is no danger of one accidentally eating some of the dose while wrestling with her sister. How long should I keep them apart? Thank you

    • Adam Retzer August 21, 2016, 10:03 pm

      There isn’t any need to keep them apart. Some of the treatment will come off in the environment as residue, and some will come off on the cats if they play. However, this won’t be a significant amount.

      The treatment is applied to the cats’ necks, so they can’t groom or lick off the concentrated dosage. However, within 24 hours the treatment will translocate over their whole bodies. After which, it’s assumed that cats will lick off and ingest small amounts of the treatment. And it’s tested for toxicity with this in mind.

  • Jill August 28, 2016, 4:03 am

    I have 3 cats two are large and one weighs about 5-6 pounds can I use 1/2 the dose of the large cat on her?

    • Adam Retzer August 30, 2016, 12:05 am

      Legally, I can’t recommend any off-label use of an insecticide product. Plus, not applying the full dose of the correct product can lead to under-dosing and control failure.

      However, if you take a look at the product label, you’ll see that all formulations contain the same ingredient concentrations. They only differ in amount of total product contained in each tube, depending on cat weight. The product for 5-9 lb cats (small cat) contains half the dose of the product for over 9 lb cats (large cat). Respectively, that’s 0.4 mL (0.014 fl oz) and 0.8 mL (0.027 fl oz).

  • Pat Kennedy August 31, 2016, 11:04 pm

    When can I bathe a cat after applying advantage ll?

  • Lisa September 14, 2016, 1:27 am

    I have a cat that is 8 pounds, and one that is 12.6 pounds. Will the advantage small cat dose (5-9 pounds) work on the larger cat?

    • Adam Retzer September 14, 2016, 12:18 pm

      You’ll likely be under-dosing the larger cat by using the small cat (5 to 9 lbs) product. Then flea control could fail. I’d recommend using the correct product for your cat size, and adhering to the product label instructions.

  • Robyn October 4, 2016, 2:39 pm

    My cat is currently on clavaceptin and elavil for a urinary tract infection and possible stones, would it still be safe to use?

    • Adam Retzer October 4, 2016, 3:13 pm

      This area is beyond my expertise. This question should be addressed to your cat’s veterinarian.

    • George October 9, 2017, 1:33 am

      Elavil… LOL. I took that in the 90’s. Good stuff. Slept like a baby.

  • Nicko October 6, 2016, 2:17 am

    What would happen if I had put the large dose on a cat lighter than 9lbs? I’m paranoid that I mis-weighed my cat because she isn’t acting normal after treating her. She seems fine, just anti-social.

    • Adam Retzer October 6, 2016, 3:00 pm

      I am not absolutely certain of the adverse effects of over-dosing. If you are concerned about this, I’d recommend contacting your veterinarian.

      The two active ingredients in Advantage II are imidacloprid and pyriproxyfen. If you scroll to the bottom of these pages, there is toxicity information.

  • Marlene November 7, 2016, 10:37 am

    Advantage 2 cats over 9 lb will it work dosage for a 17 mature cat

    • Adam Retzer November 7, 2016, 2:15 pm

      That would be the correct product to use. If you’re concerned about under-dosing, because the cat is so large, then I’d recommend consulting with your veterinarian for further advice.

  • Deanna November 20, 2016, 9:51 am

    I have 2 cats one is 18lbs & other is 19 lbs is just 1 dose of the large cat advantage good enough?

    • Adam Retzer November 22, 2016, 12:07 pm

      Yes, it should be enough, based on the product specifications. However, if you’re worried about under-dosing, you may want to contact your veterinarian for consultation. I’m not qualified to give advice regarding off-label insecticide use.

  • Andrew November 21, 2016, 2:16 pm

    My cat weighs 20lbs (male maine coon)… I’m concerned that the 9+ lb dose is not enough. I ask because within 2-3 days I start to notice dead fleas and I will comb them out, but it certainly does not last anywhere close to 30 days. Within 2 weeks there are usually live fleas again. Is this because of his large size? if so, should I be applying more frequently than 30 days? or is there a higher dose available? (for example one 0.8ml dose + one 0.4 or one 0.23ml dose?)

    • Adam Retzer November 22, 2016, 12:48 pm

      Hi Andrew. Your reasoning makes sense to me. However, I don’t have the qualifications to answer your question or provide off-label advice for insecticides. I’d recommend contacting your veterinarian for dosage advice.

  • Tonya November 26, 2016, 11:03 am

    I have 2 cats, they are both about 9lbs. I applied a dose of the advantage 2 for the cats that are 9lbs and under a little under a month ago. I have noticed that one of my cats is scratching pretty badly, Will it hurt to apply another dose even thought it hasn’t been a month yet?

    • Adam Retzer November 26, 2016, 2:05 pm

      Hello Tonya. I can’t give advice that deviates from the instructions on the label. I wouldn’t want to inadvertently cause harm to your pets. This question should be addressed to your cats’ vet.

  • Julie Clark December 1, 2016, 7:25 am

    We have a 28 pound Maine Coon. Do I need to give him a bigger dose?

    • Adam Retzer December 1, 2016, 12:36 pm

      Many people with Maine Coons are asking this question, and it is a good question. Unfortunately, I can’t provide much help. It’s a violation of federal law to use insecticide products in a manner inconsistent with the labeling (so-called off-label use). Only a qualified veterinarian will be able to address this issue properly, and give advice on dosage that deviates from the label’s instructions.

    • Joe buthiss December 18, 2017, 9:43 am

      My 35 pound cat is a canadian coon cat and his name is lard ass the killer because i have seen him beat up all of the little pussy maine coon cats in the neighborhood and they all had fleas so i think lard ass got his fleas from those nasty maine coons. Lard ass has fleas the size of a small kitten. I was wondering if I should give lard ass two doses of the large cat advantage 2.

  • Colleen December 28, 2016, 9:17 pm

    If you read the specs on Advantage, it is safe to treat every 2 weeks- or at least it used to be.

    • Adam Retzer December 28, 2016, 9:46 pm

      That’s true Colleen. I’ve actually recently added that information at the bottom of the article. My older comment replies might not reflect that though. Thank you for highlighting it.

  • MikeChase January 4, 2017, 7:06 pm

    Can somebody break down
    the doses in drops
    We’ve been doing one drop per pound for years now
    just want to confirm

    • Holli March 2, 2017, 11:15 am

      Hi Mike,
      I’m not a vet or a vet tech, but I have a B.S. Health degree. During my science based training, I can tell you for certain that ‘a drop’ can vary greatly in quantity. For instance, if the tube is very full, a drop will be larger than if the tube is being squeezed for the last bit of liquid. Also, a gentle squeeze will produce a smaller size drop while a hearty squeeze will produce a larger one. One can never base science and medicine on perceived amounts such as drops.

  • Joe January 8, 2017, 9:41 pm

    I have a 12lb cat I made a mistake of not putting any flea meds on him before letting him out now he has brought fleas into the house since then I’ve applied 2 doses in 2 months & I still find fleas on him I want to apply the 3rd sooner than a month it’s been almost 2 weeks since the last dose is it safe to apply another dose this soon? Please help thank you

    • Adam Retzer January 11, 2017, 2:19 pm

      In the directions, it’s stated that retreatments can be done sooner than monthly in order to establish control. Then the monthly schedule should be adhered to after control is attained. For large cats, it says not to retreat more than once every 7 days.

      Keep in mind, you’ll likely continue see fleas here and there. They develop in carpets, and the adults will eventually emerge to jump onto the cat. The flea drops will kill the fleas, but it can take a few hours (sometimes up for 24 hours). It usually takes around 8 weeks before all the immature stages in the environment mature, emerge and die as adults.

  • Donna March 2, 2017, 3:37 am

    Have advantage for cats under 10 lbs by mistake and my cat is 171/2 lbs. Can I use two of those doses or will the one small dose work on him?

    • Adam Retzer March 2, 2017, 5:45 pm

      I’m not sure which product you applied to your cat. You mentioned that you used one for cats under 10 lbs, but there are two products that fit this category: small cats (2 to 5 lbs) and medium cats (5 to 9 lbs).

      I can’t recommend any course of action. However, I will say that the medium cat treatment tube contains 0.4 mL. And the large cat treatment tube contains 0.8 mL. And the active ingredient formulation is identical in all products.

  • David Kretovics April 9, 2017, 11:11 pm

    I accidentally double dosed my cat with Advantage 2 five hours after the first one, what do I do?

  • Heather Cahn April 29, 2017, 5:40 pm

    I have a 27lb cat that I used the large cat dosage of Advantage II and he’s still scratching a lot.. Should I use 2 of the 9lb+ viles or just one?.

    • Adam Retzer May 2, 2017, 3:12 pm

      Heather, it sounds you may have a Maine Coon? Many visitors seem to have questions regarding this large cat breed. I can only advise to follow the label. This would mean using 1 tube of the 9lb+. If this doesn’t solve the problem, the cat can be retreated earlier than 1 month (no more than once every 7 days).

      It may be a good idea to contact your cat’s veterinarian for more specific advice. 27lbs is large, and the vet may recommend using a larger dose. However, I wouldn’t trust any advice posted online about this, as it is against the law to recommend off-label use unless you’re a qualified vet, and you wouldn’t want to overdose your cat.

  • Sherry May 16, 2017, 6:59 pm

    My new kitty has exceptionally long, thick hair. A lot of the flea medicine doesn’t get through to his skin and he gets infested again two weeks later. Any suggestions on how to apply Advantage to cats like this?

    • Adam Retzer May 23, 2017, 2:23 pm

      I’d pay special attention to the instructions regarding parting the cat’s hair to ensure the treatment is applied directly to the skin. Once it’s on the skin, it incorporates into the sebaceous (oil) layer. The body’s natural oils then naturally spread the treatment over the animal within 24 hours.

      If the infestation is severe and difficult to control, you can re-apply the treatment early (as in the instructions). For kittens (2-5 lbs.) retreatment shouldn’t be done more often than once every 14 days.

  • Trish vadden July 1, 2017, 7:57 am

    I’m in a panic ! I just mixed up the flea dosage – I gave my 7lbs cat the dosage for 9lbs I called my vet but they told me to call your company I called your company but they only answer Monday Friday 8-5 I’m really nervous and don’t know what to do !

    • Adam Retzer July 2, 2017, 12:54 pm

      Trish, I don’t own any flea control product company. I just provide information from research on

      You are going to want to contact Bayer, the maker of Advantage. Please see their contact page here:

      Here’s a snippet from that page:
      If you have a question about one of our products, please contact a member of our Veterinary Technical Services team at (800) 255-6826.

    • Amanda K Cox December 18, 2017, 11:05 pm

      Trish, I am extremely curious as to what happened with your 7 lbs baby. I have 2 cats, 1 over 9 lbs and 1 at 8 lbs and would like to know if I could use the advantage2 for large cats instead of buying both products. To find out what happened with your cat will help me know if it will work or harm mine. Thank you!

  • Dana Rickgauer September 14, 2017, 6:43 pm

    I have a kitten born 6/19/17 I only put a few drops of advantage on him 8/23/17. Is it safe to use advantage ll fir small cats on him now. I’m thinking he is about 3lb

    • Adam Retzer September 29, 2017, 10:32 am

      It should be safe to use Advantage on him if he is over 8 weeks old. However, if he is only 3 lbs, you’ll want to use the Advantage II for Kittens (2-5 lbs), not Advantage II for Small Cats (5-9 lbs).

  • Kevin Guess September 16, 2017, 2:18 pm

    I mistakenly bought the 5-9lb dosage for kittens who range from 3.5 to 4.5 lbs. My wife applied it without realizing it wasn’t the right dosage. Should we worry? Is there anything we need to do?

    • Adam Retzer September 29, 2017, 10:37 am

      This may cause problems related to overdosing. I’d suggest contacting your veterinarian to see if there are any risks and related actions that need to be taken.

      • George October 9, 2017, 1:34 am


  • Braden October 9, 2017, 5:56 pm

    I have found a dosage of the kitten one and my cat is now 2 years old, i put it on him just so i wasnt wasting it. It wont harm him will it

    • Adam Retzer October 16, 2017, 2:48 pm

      You should always use the correct treatment that corresponds to your cat’s weight. You could be under-dosing your cat, and then the treatment won’t be effective. Or, if you are adding it to another treatment, you could be overdosing and causing toxicity issues.

  • Lynda Jennings October 22, 2017, 10:45 am

    I have a 16 year old cat that I have been treating with Advantage II on a monthly basis. I have been using dosage for 5-9 lb. weight . She now weighs 5 lb. 4 oz. Should I continue using dosage for 5-9 lb. weight or should I use dosage for 2-5 lb.weight? Thank you.

    • Adam Retzer October 24, 2017, 2:40 pm

      I can only advise to use the product that corresponds to the cat’s weight, the 5-9 lb. weight. If you’re worried about overdosing since the cat is getting older and its weight is getting close to borderline, then I’d recommend contacting your cat’s veterinarian for further advice. Anyone who isn’t a licensed veterinary professional can’t legally recommend any use that deviates from the labeled instructions.

  • Amber November 10, 2017, 8:36 pm

    Is it safe to give my cats a dose every 2 weeks rather than once per month? My cats are pretty heavy, one is 11 lbs and the other is 17 lbs. From what I’ve read, it seems so, I just want to make sure.

    • Adam Retzer November 13, 2017, 12:41 pm

      Yes, you can re-dose early, as per the instructions. Usually this is done when infestations are severe, in order to establish control. I recommend reading the label to get the exact information.

      This is the information I’ve found from the labels:
      For kittens (2-5 lbs.), retreatment shouldn’t be done more often than once every 14 days. For small cats (5-9 lbs.) and large cats (over 9 lbs.), do not retreat more than once every 7 days. Once flea control is attained, the monthly re-treatment schedule should be adhered to.

  • Gjoka November 16, 2017, 12:10 am

    I mixed up my dosages by accident and had my cat that weighs about 6-7 pounds the advantage 2 for large cats. If my cat in serious danger? I can’t find anything about it and my vet isn’t open right now! Thank you

    • Adam Retzer November 16, 2017, 12:07 pm

      I can’t advise you with this issue. I’d recommend waiting until your vet is open, or contacting another veterinarian. The product label also provides a number to call for medical issues: 1-800-422-9874.

  • Tori January 22, 2018, 7:47 am

    The vet gave me some flea meds for my cats. One of my cats weighs about 6 lb and I accidentally gave her the one for my other cat which is rated between 9 and 18 lb. I panicked and washed a little bit of it off. Is it going to hurt her?

    • Adam Retzer January 30, 2018, 2:29 pm

      Tori, unfortunately I am not qualified to answer this question. You need to contact your cats’ veterinarian.