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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. Trifexis requires a prescription from your veterinarian.


Dogs (8 weeks of age and older and weighing at least 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 it Works:

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 information 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 (140mg/2.3mg)), Orange box for dogs 10.1 to 20 lbs (270mg/4.5mg), Green box for dogs 20.1 to 40 lbs (560mg/9.3mg), Blue box for dogs 40.1 to 60 lbs (810mg/13.5mg), and Brown box for dogs 60.1 to 120 lbs (1620mg/27mg). For dogs over 120 lbs give the appropriate combination of tablets.

What is Trifexis:

Trifexis is a chewable, beef flavored tablet that is made out of pork liver and hydrolyzed soy and given to your dog once month to prevent heartworm, to prevent and treat flea infestations, and to treat and control adult hookworm, roundworm, and whipworm infections. 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.

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 this medication be given:

Give Trifexis chewable tablets with food. Give Trifexis chewable tablets once a month. Trifexis chewable tablets may be chewed, offered in food, or administered like other tablet medications. If vomiting occurs within 1 hour of administration, redose the pet with another full dose. Store Trifexis at room temperature (68-77° F). Consult your veterinarian for pregnant or lactating dogs.

What happens if I miss a dose:

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

What happens if I overdose the pet:

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:

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 are the possible 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 the pet.

What other drugs will affect Trifexis:

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

Where can I get more information:

Your pharmacist has additional information about Trifexis written for health professionals that you may read.

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

Should be stored at room temperature. Keep away from pets and children.

Trifexis for Dogs 5 to 10 lbs:
Active Ingredients per tablet
140 mg
Milbemycin oxime
2.3 mg
Trifexis for Dogs 10.1 to 20 lbs:
Active Ingredients per tablet
270 mg
Milbemycin oxime
4.5 mg
Trifexis for Dogs 20.1 to 40 lbs:
Active Ingredients per tablet
560 mg
Milbemycin oxime
9.3 mg
Trifexis for Dogs 40.1 to 60 lbs:
Active Ingredients per tablet
810 mg
Milbemycin oxime
13.5 mg
Trifexis for Dogs 60.1 to 120 lbs:
Active Ingredients per tablet
1620 mg
Milbemycin oxime
27 mg
Customer Reviews
Trifexis is rated 3.7832618025751072 out of 5 by 466.
Rated 5 out of 5 by from Love this preventive medicine for my dog I have had Bella on Triflexis for over a year. She takes the chewable as though it is a treat and has never had an issue with it thus far. She is a dog with severe skin allergies, so having a product like this that keeps the pests off of her and does not give her skin a bad reaction has been a lifesaver. I have not found one flea or tick on her since I started it, unlike the topical treatments I have tried in the past. Plus having the heartworm/roundworm prevention apart of it gives me reassurance knowing that she is safe. Plus buying it on PetMeds has saved me a bunch!
Date published: 2016-07-16
Rated 4 out of 5 by from smells really bad hard to get dog to take it and k I used this on my long haired miniature daschund it smells like bleach to me I found that she threw up outside after she had taken it I waited until the next month to try again then she got all weirded out it was like she didn't know where she was or how to get back into the house and she was on a leash afraid to give it to her this month I think it is too strong I think she should have the one up to 10lbs cause she only weighs 11 lbs instead of the dose for 20lb dog I have to call the vet to see if maybe I can cut it in half dont really Cate for it it should smell better cause my dog has a good nose and so do I
Date published: 2016-07-12
Rated 5 out of 5 by from ABSOLUTELY AWESOME Definitely love Trifexis! I adopted my dog 3-4 year old Pharoah Hound Mix 8 months ago and this is what I have her on. We've never had a bad reaction to it and it protects against 3 types of worms, heartworms, fleas and eggs at the same time in one tablet which is super convenient for me AND an all in 1 tablet SAVES ME MONEY instead of buying multiple prescriptions! Love that my sweet girl is protected by this awesome product especially since we're outside 99.9% of the time either camping or hiking! (':
Date published: 2016-07-10
Rated 1 out of 5 by from Dog keeps throwing up I have a 2 yr old Weimaraner. I give this pill with food & my dog keeps throwing it up. Out of my 6 month supply he only kept one down. Too expensive to give & not use. Looking for something different.
Date published: 2016-07-10
Rated 5 out of 5 by from I've been using Trifexis on my Chiuahua for almost 5 years and he has never had a bad reaction. He takes it without any problems and in all the time I've been using it he has never had a flea or parasite infestation. I'm very happy with th product. I do wish it was a little less expensive but other than the cost I've found it works great!
Date published: 2016-07-06
Rated 2 out of 5 by from Bad taste and vomiting dog I bought a 6 month supply from my vet. I was instructed that it tastes bad, try to give with food, and if the dog vomits give another tablet. We destroyed the first tablet trying to think of ways to disguise the taste and had to use up another tablet. Months 2-4 were tolerable but heavily coated in peanut butter and wrapped in lunchmeat. For month 5, my last tablet since I wasted one, was also covered in PB and meat. But we came home to find vomit all over the kitchen. I will not be ordering this product again.
Date published: 2016-06-29
Rated 4 out of 5 by from Long term trifexis user I've been using trifexis since I got my dog two and a half years ago. I have never had a problem and she has had nothing but good results with this pill . The only con is the smell(and I assume taste) it is very strong unpleasant smell and my dog does not eat it willingly. I usually have to cut it up and hide it in peanut butter.
Date published: 2016-06-28
Rated 5 out of 5 by from Tips & tricks My dog Copper has been on Trifexis since he was a puppy, & he will be 4 in Oct, 2016. This is my 2nd dog on Trifexis, & I won't use anything else. I will share a few tips & tricks that I had to figure out the hard way: 1.) Make sure your dog is taking the pill on a full stomach. My dog is on bagged food & found for pulling the dog wet food works the best, plus it's a treat for my dog. So I buy two cans of dog food & give one before I give the pill. 2.) Coat the pill. I used to cover the pill in softened butter, but found coconut oil coats the pill better, & makes pilling easier on the dog. 3.)Once the pill is down the hatch. Immediately give the 2nd can. If your dog is not full, you WILL be digging through vomit to retrieve that pill. Even worse if your dog chews it up (like my first dog), you can hang up getting that pill back. 4.)Do not pill your dog on high activity day. I just personally don't do it, for fear of losing a pill. Plus we have a large yard & if he did throw up, I may never know it. Do it on a day where you can closely monitor your dog. Even as long as my dog has been on it, I still monitor him. 5.) Don't give it too him before bed (did that once BEFORE I went to the two can method & went to the bathroom in the middle of the night & stepped in a hug pile of thrown up Trifexis & dried dog food- yeah that went well). Final thoughts: The pill does work, between 2 dogs I have lost 3 pills, & that's because I didn't know what I was doing. Expensive mistakes. I am a forgetful person so having my dog on worming meds (heart, wip, hook, & round worms), flea meds, & tick meds just would not work for us. The Trifexis covers the worm issues, & fleas. We just keep a tick collar on him in tick season. Sorry my review was so lengthy, hope this helps.
Date published: 2016-06-27
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Is it safe to combine this with Heartgard?

Asked by: Heather
It is suggested not to combine Trifexis with other medications that contain Ivermectin which is in Heartgard.
Answered by: paulpharmacistintern
Date published: 2016-07-26

Does it protect against ticks as well?

Asked by: Snider14
Trifexis oral medication will treat fleas but it does not protect against ticks.
Answered by: paulpharmacistintern
Date published: 2016-07-26

I used frontline 2 weeks ago but not working.  Can i give my dog triflxis

Asked by: Laura
Frontline Plus is a over the counter flea and tick treatment. Trifexis is a prescription heartworm preventative, worm treatment and it kills adult fleas. We will advise you to speak with your vet on using Trifexis.
Answered by: Carolyn Petmed Pro
Date published: 2016-07-21

Is the pricing plus tax?

Asked by: Robert
Thank you for your question. Currently there is no tax on prescription medications.
Answered by: James PetMeds Pro
Date published: 2016-07-21

How often is the product given---is it once every 4 weeks?

Asked by: dell3865
You will give your pet 1 pill every month.
Answered by: Carolyn Petmed Pro
Date published: 2016-07-21

I still have some but they are over a year old can I still use them

Asked by: veeda
If your dog has not missed any monthly treatments, check the expiration date on your Trifexis to see if it is still good. Most product has an expiration date that is over a year from when our hospital purchases it from the manufacturer.
Answered by: SuztCVT
Date published: 2016-03-18

I have a 16 week old lab puppy who weighs 30 lbs. what size Trifkexus should I buy as he will go past the 40 lb within two months?

Asked by: Annie
Please check with your Pet's Veterinarian as to what the proper medication and dosage should be based on your pets age and size.
Answered by: Pharmacy Manager
Date published: 2016-03-12

How soon can I give my yorkie trifexis? 

Asked by: Rosie
Trifexis is safe to administer in pets 8 weeks or older who weigh at least 5 pounds.
Answered by: Lisa M
Date published: 2016-03-08
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