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Product Info
How to Use
Customer Reviews
Product Info

What is Trifexis?

Trifexis is a chewable tablet that kills fleas and prevents infestations, protects against heartworms, and treats and controls adult hookworm, roundworm, and whipworm infections. This tasty, beef-flavored tablet (containing pork liver and hydrolyzed soy) is easy to give your dog to protect against multiple parasites with one medication. Trifexis chewable tablets are for monthly use in dogs and puppies 8 weeks of age and older and 5 lbs of body weight or more. Trifexis requires a prescription from your veterinarian.


Dogs (8+ weeks of age, weighing 5+ lbs)


  • Begins killing biting fleas within 30 minutes
  • Kills fleas before they can lay eggs
  • Prevents heartworm disease
  • Treats and controls roundworms, hookworms, and whipworms
  • Artificial beef flavor made from pork liver and hydrolyzed soy
  • Easy-to-administer chewable tablet

How does Trifexis work?

Spinosad, an active ingredient in Trifexis, starts to work within 30 minutes to kill fleas and has been proven to kill 100% of all biting fleas within 4 hours. Trifexis also kills flea eggs before they can mature, which helps to end the flea life cycle. Trifexis prevents heartworm disease by killing microfilariae and larvae from maturing into adult heartworms.


Serious adverse reactions have been reported following concomitant extra-label use of ivermectin with spinosad alone, one of the components of Trifexis chewable tablets. Use with caution in breeding females. The safe use of Trifexis in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy. Puppies less than 14 weeks of age may experience a higher rate of vomiting. Consult your veterinarian for pregnant or lactating dogs.

Brand Name:

Trifexis (Elanco Animal Health)

Generic Name:

Spinosad and Milbemycin oxime

What is the most important thing I should know about Trifexis?

Trifexis is a prescription medication FDA approved for use in dogs 8 weeks of age or older and 5 lbs of body weight or more. Trifexis contains spinosad and milbemycin oxime and is indicated for the prevention of heartworm disease. Trifexis kills fleas and is indicated for the prevention and treatment of flea infestations, and the treatment and control of adult hookworm, adult roundworm, and adult whipworm infections. Trifexis is available in a Pink box for dogs 5 to 10 lbs (140 mg/2.3 mg), Orange box for dogs 10.1 to 20 lbs (270 mg/4.5 mg), Green box for dogs 20.1 to 40 lbs (560 mg/9.3 mg), Blue box for dogs 40.1 to 60 lbs (810 mg/13.5 mg), and Brown box for dogs 60.1 to 120 lbs (1620 mg/27 mg). For dogs over 120 lbs, give the appropriate combination of tablets.

What should I discuss with my veterinarian before giving Trifexis to my pet?

Tell your veterinarian if you are planning on breeding your pet. Tell your veterinarian if your dog has a history of seizures (epilepsy).

How should Trifexis be given?

Give Trifexis chewable tablets once a month with food. Trifexis chewable tablets may be chewed, offered in food, or administered like other tablet medications. If vomiting occurs within 1 hour of administration, redose your pet with another full dose. Consult your veterinarian for pregnant or lactating dogs.

What are the potential side effects of Trifexis?

Side effects that may occur include vomiting. If vomiting occurs within one hour of administration, redose with another full dose. Other side effects may occur. Continue giving Trifexis chewable tablets and talk to your veterinarian if your pet experiences decreased appetite, lethargy or decreased activity, diarrhea, cough, increased thirst, vocalization, increased appetite, redness of the skin, hyperactivity and excessive salivation. Talk to your veterinarian about any side effect that seems unusual or especially bothersome to your pet.

What happens if I miss giving a dose of Trifexis?

Give the missed dose with food as soon as you remember and resume a monthly dosing schedule.

What happens if I overdose my pet on Trifexis?

Overdose of this medication is unlikely. However, if an overdose is suspected, contact your veterinarian or veterinary emergency room. Symptoms of overdose that may occur include vomiting.

What should I avoid while giving Trifexis to my pet?

Your pet may maintain normal activities and interactions while being given Trifexis. The safe use of Trifexis chewable tablets in male dogs intended for breeding has not been established.

What other drugs will affect Trifexis?

Talk to your veterinarian before giving any prescription or over the counter medications.

How to Use

Trifexis Directions:

  • Please view the chart below for the correct dosage of Trifexis for your dog.

Trifexis does not protect against ticks. To help control ticks, try the Preventic Tick Collar.

Dogs (8+ weeks of age, weighing 5+ lbs)
5-10 lbs
Give one tablet (Pink box)
10.1-20 lbs
Give one tablet (Orange box)
20.1-40 lbs
Give one tablet (Green box)
40.1-60 lbs
Give one tablet (Blue box)
60.1-120 lbs
Give one tablet (Brown box)
Over 120 lbs
Administer the appropriate combination of tablets
Do not use!
Do not use!

Store Trifexis at room temperature (68°-77° F).


Trifexis Ingredients:

Trifexis Pink box (5-10 lbs):
Active Ingredients per tablet
140 mg
Milbemycin oxime
2.3 mg
Trifexis Orange box (10.1-20 lbs):
Active Ingredients per tablet
270 mg
Milbemycin oxime
4.5 mg
Trifexis Green box (20.1-40 lbs):
Active Ingredients per tablet
560 mg
Milbemycin oxime
9.3 mg
Trifexis Blue box(40.1-60 lbs):
Active Ingredients per tablet
810 mg
Milbemycin oxime
13.5 mg
Trifexis Brown box(60.1-120 lbs):
Active Ingredients per tablet
1620 mg
Milbemycin oxime
27 mg
Customer Reviews
Trifexis is rated 3.9 out of 5 by 538.
Rated 5 out of 5 by from Works Great !!! My dog Madison has been taking Trifexis ever since we purchase her at 3 months old. She will be 6 on March 29, 2017. At the beginning I had to give a treat to take it, after a while when she see me cut the pill from the packaging she can't wait & it works. She has never had fleas. When she goes for a doctor visit or boarding when we travel, the doctors never find fleas.
Date published: 2017-03-19
Rated 2 out of 5 by from Dogs hate the taste and throw up hours later I used Trifexis for my basenji and my pitbull for a couple years. Every month it was a huge ordeal trying to get either of them to take it. They hate the taste, and no matter what I'd hide the medicine in, they'd know and refuse to eat it. My basenji would throw up a few hours after every single dose, but her vet said it wasn't a big deal. It turns out that was a sign I should have changed vets sooner. Our current vet told me that is a big problem with Trifexis, and immediately switched us to a different medication. Trifexis is also ridiculously expensive, especially for something that my dogs just threw up. I'm only giving it 2 stars rather than 1 because we never had any issues with fleas or heartworm. There are definitely better options out there, for your dog and for your wallet.
Date published: 2017-03-18
Rated 5 out of 5 by from Much easier and less messy than other options My Cairn Terrier eats these tablets like candy with no ill side-effects. Now my wife has no (good) excuse not to administer his meds when I'm not at home. These pills have been proven effective against heart worms in addition to tick and flea protection. Make the change, you won't regret it.
Date published: 2017-03-12
Rated 4 out of 5 by from Trifexis I have 4 dogs and they are all on trifexis, use to be on sentinal, they are very skeptical when taking their pills, seem to know it is mixed in the food, I have to either shove it down there throats or really trick them. They do not have any issue with bugs at all. Not even really any ticks. I just wish with the amount of dogs it was not so expensive. I love my dogs and had them since they were pups and hate for them to be sic. Had two that died of heartworm when treated, very sad thing.
Date published: 2017-03-10
Rated 5 out of 5 by from We have been in Florida for 7 months clearing land. I have stirred up a lot of ticks, and I have had to get them off of me, Shadow hasn't had any. This is a daily inspection for us. I may have to take Trifexis for me. LOL
Date published: 2017-03-07
Rated 5 out of 5 by from Easy to give to my dog , super easy ordering !! Purchased this at the recommendation of my vet , easy to give to my dog and she ate it quickly , no problem !!
Date published: 2017-03-06
Rated 4 out of 5 by from Easy to maintain a heart healthy pup! 1-800 makes it so easy to keep my pup on these meds which keep him healthy. We've never seen a side effect in my 45 lb. Shar-Pei. He's also never had heart worms, fleas or ticks. Putting it into his meal as a broken tablet works well for him. Wouldn't take him off it for anything else.
Date published: 2017-03-05
Rated 4 out of 5 by from Happy with it! My dog seems to do very well with Trifexis. She gets a little tired after I give it to her, but no other major side effects.
Date published: 2017-02-28
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What does the 20 to 40 lb pill look like

Asked by: Nova
You can see a photo of what the tablets look like on this website to the left of where you select the weight range and quantity of the tablet you want to purchase. Only the size of the tablets will be different depending upon the weight range.
Answered by: SuzyCVT
Date published: 2017-03-18

Is Trifexis affective in killing heartworm? 

Asked by: James
Being a heartworm prevention, it is very affective at killing the infective larval stages of heartworms, but no heartworm prevention will kill the adult worms. Giving heartworm prevention to a dog that already has adult heartworms will prevent the dog from being further infected and in time, usually 2 or more years, the adult heartworms will die because it is the end of their normal lifespan. The unfortunate part is that the dog will still be subject to all the bad affects of having adult heartworms during those years.
Answered by: SuzyCVT
Date published: 2017-03-18

Can I crush the tablet and mix it in their food to administer? My dog does not like the taste of the tablet. 

Asked by: Cher
My vet reccomended to let the tablet sit out on the table for a few hours so the "dirt" smell will dissapate. Then I crush it and mix it with some wet food.
Answered by: Jfl23
Date published: 2017-03-16

If confortis has the same ingredients as trifexis it should kill ticks too right

Asked by: Bkfla79
Both medications have the active ingredient of spinosad, which is approved for treating and preventing fleas. Trifexis also has the active ingredient milbemycin oxime which is for control/preventative of worms. Neither of these drugs are approved for ticks.
Answered by: Ben B
Date published: 2017-03-13

Will it kill ticks

Asked by: Big Daddy
It's got same ingredients as confortis it should kill ticks too
Answered by: Bkfla79
Date published: 2017-03-13

Why is this 112.96

Asked by: Moes
For questions about pricing, contact our customer service at or 1-800-Petmeds
Answered by: Ben B
Date published: 2017-03-06

Dog weights 149 lbs. Cost for 6 mo. supply?

Asked by: Mackie
With your dogs weight, they will need 1 tablet from the brown box (60-120lbs) and 1 tablet from the green box (20-40lbs) to get the appropriate dosage. Therefore a 6 month supply for the green box and brown box of Trifexis will cost ~$221 total. Hope this helps.
Answered by: Trey W
Date published: 2017-02-27

My 6 month old puppy (15 lbs) just took her comfortis and also stole another dog's trifexis (40-60 lbs) will this be a trip to the vet?

Asked by: Ford
Hello Ford, I know that is alarming to find out, as that is a lot. Fortunately both these drugs contain the same active ingredient (spinosad) for fleas and they are both normally well tolerated. I would recommend watching your pet and calling your vet immediately if you see anything unusual or any serious side effects happening, such as vomiting or seizures. The main side effect in both these drugs is vomiting. You can then continue with the normal monthly regimen. Hope this helps. Thanks, Pharmacy student intern
Answered by: Trey W
Date published: 2017-02-16
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