Last Updated: December 31, 2020
Celia Miller Author: Celia Miller

Best Oral Flea Medication for Cats

Best Oral Flea Medication for Cats

The most crucial factor to consider when choosing an oral flea medication for your cat is efficacy–how long the product will last. We recommend that Comfortis, our number one pick, be used every month for ongoing flea control. We further recommend that Capstar or CapAction be used to help control flea infestations on an as-needed basis. 

Best Products Best Oral Flea Medication for Cats

Choose a charity on Amazon Smile on Spots.com then purchase
via links on this page to donate a portion
of your purchase. Learn more »
Best Overall
Comfortis (aka VCA’s AcuGuard) Flea Medication for Cats
Comfortis (aka VCA’s AcuGuard) Flea Medication for Cats Best Overall
$102
Review manufacturer chewy
on chewy
9/10
  • What we Like
  • Kills adult fleas
  • Chewable, beef-flavored tablets
  • Kills on contact versus biting
  • Safe for human contact immediately
  • What we Dislike
  • Is not ideal for food-allergic cats
  • Most common side-effect is vomiting
Product Details
Speed Starts killing fleas in 30 minutes
98% fleas eliminated within 4 hours
Efficacy 30 days
Safety Safe for kittens and cats more than 14 weeks of age
weighing more than 4.1 lbs
Availability
Our Review

Comfortis, also sold as AcuGuard through VCA clinics, is the #1 recommended prescription flea-only medication. 98% of fleas dying within 4 hours is phenomenal for any product, let alone an ingestible one. The active ingredient, Spinosad, is derived from naturally occurring bacteria. When ingested by fleas, the fleas become paralytic and confused, dying before they can lay eggs. Because fleas and mammals do not share the same Spinosad reaction, it will not cause pets to have neurological issues. The product is so safe that it won the Presidential Green Chemistry Challenge Award in 1999 from the U.S. Environmental Protection Agency. Vomiting may occur with the first and perhaps 2nd dose but usually resolves, especially if given with a meal. If your cat has allergies to pork-based food, this medication may not be the best choice for you. And, fleas must bite your cat for this flea medication to work.

Best Non-Prescription
Capstar and CapAction Flea Medication for Cats
Capstar and CapAction Flea Medication for Cats Best Non-Prescription
$25
Review manufacturer amazon
on amazon
9/10
  • What we Like
  • Kills adult fleas
  • May use in conjunction with other flea prevention products
  • May give with or without food
  • Safe for breeding or pregnant cats
  • What we Dislike
  • Fleas have to bite to receive the parasiticide
  • Active for only 24 hours
Product Details
Speed Starts killing fleas in 30 minutes
90% fleas eliminated within 6 hours
Efficacy 24 hours
Safety Safe for kittens and cats more than 4 weeks of age and between 2 and 25 lbs
Availability Sold without a prescription
Our Review

We’ve grouped these products because they all contain the same active ingredient, Nitenpyram (11.4%). Both Capstar and CapAction are especially beneficial under conditions such as acquiring a new cat who has fleas, treating a flea infestation, and treating a feral cat. These products work quickly, killing fleas within 30 minutes and eliminating 90% of fleas within 6 hours. If your cat is already on flea control treatment, or you’re fighting a flea infestation and need some extra help, these products are a great choice. Per the manufacturers, these products are safe for breeding and pregnant cats and safe to use with fleas shampoos, heartworm preventatives, and other medications. We recommend reading the label and checking with your veterinarian for guidance if your cat has health issues and takes other medications.

Flea Away Natural Flea, Tick, and Mosquito Repellent for Dogs and Cats
Flea Away Natural Flea, Tick, and Mosquito Repellent for Dogs and Cats
$19
Review manufacturer amazon
on amazon
4/10
  • What we Like
  • Repels fleas, ticks, and mosquitos
  • May use in conjunction with other flea prevention products
  • Safe for breeding, pregnant, and nursing cats
  • What we Dislike
  • Large tablet size
  • Does not kill existing fleas or ticks; repels only
  • Must give daily
Product Details
Speed 30 days to begin to work
Efficacy 24 hours
Safety Safe for kittens and cats of any size and age
Availability Sold without a prescription
Our Review

This flea control product does not kill fleas, ticks, and mosquitos; it may repel these insects after 30 days of use. According to the maker, these parasites come to dogs and cats because they smell CO2 and the natural ingredients within this product portend to mask that smell, making the dog or cat far less appealing to these annoying bugs. Active ingredients include a proprietary blend of brewer’s yeast, calcium carbonate, cyanocobalamin, folic acid, niacin, pyridoxine HCl, and thiamine HCl dl-alpha-tocopheryl acetate. The tablet’s flavor comes from beef liver and byproducts, so beware if your cat is food allergic. The tablet size is also quite large and would likely need to be broken or ground to administer.

Only Natural Pet Brewer's Yeast & Garlic Skin & Coat Chewable Tablets Dog & Cat
Only Natural Pet Brewer's Yeast & Garlic Skin & Coat Chewable Tablets Dog & Cat
$30
Review manufacturer amazon
on amazon
3/10
  • What we Like
  • Repels fleas, ticks, mosquitoes, and biting insects
  • Chewable tablet
  • Product 100% guaranteed
  • Formulated by holistic veterinarians
  • What we Dislike
  • Does not kill existing fleas or ticks; repels only
  • Must give daily
Product Details
Speed

information provided
Efficacy 24 hours
Safety Safe for kittens and cats of any size and age
Availability Sold without a prescription
Our Review

This all-natural insect repellent uses the primary active ingredients of Brewer’s yeast and garlic. The manufacturer claims this product uses human-grade ingredients and that holistic veterinarians have formulated it. This product does not kill fleas, ticks, mosquitos, or other insects; it repels these insects using the scent of garlic and yeast. The company asks pet parents to discuss the use of this product with their veterinarian for breeding, pregnant or nursing cats, cats with health issues, and using this product with other medications. This product is considered a supplement and therefore given daily, although the company suggests skipping one day per week.

Best Products Best Oral Flea Medication for Cats
Product Name Best for Rate
Comfortis (aka VCA’s AcuGuard) Flea Medication for Cats Best Overall 9
Capstar and CapAction Flea Medication for Cats Best Non-Prescription 9

How to Choose:

While topical flea drops are the most common type of flea control available for cats, oral flea control offers some distinct advantages, such as the velocity of killing fleas and safety for you and your family. With oral flea medications, you do not need to be concerned with touching your pet following the drug administration, nor do you need to separate your pet from other household pets. 

How fast these products kill fleas is relatively consistent, except for the all-natural products which do not actually kill parasites, but repel them. Both Comfortis and Capstar (and similar products) begin to kill fleas in 30 minutes and eradicate them from your pet within 6 hours. Only Catego and Vectra topical flea products eliminate fleas as fast as these oral products. 

Oral Flea Care Is Easier and Safer

The real advantage of oral products is that you don’t have the mess of a topical liquid to apply, nor do you and your family have to be separated from your cat. Finally, your cat may remain with your other pets versus with a topical where the danger of oral ingestion is an issue. We all know animals love to groom each other. 

The benefit of each oral flea medication depends on its use. We recommend Comfortis, our number one pick, be used every month for ongoing flea control. We further recommend Capstar be used to help control flea infestations on an as-needed basis. We base these recommendations on the principles of overall flea control, including the prevention and treatment of flea infestations. Comfortis is effectual in cats for 30 days, whereas Capstar (and like products) is effective for 24 hours or less. Comfortis and topical flea drops  help prevent flea infestations. Capstar (and similar products) help treat flea infestations.

In this article, we’ve also reviewed two available all-natural oral flea products. Our ratings are not high, nor do we recommend these products. We based our recommendations on two factors:

 

  • These products do not kill fleas; they help repel fleas and other insects naturally. Once your cat has a flea infestation, preventative treatments are not going to solve the problem.  
  • “Essential oils, including peppermint oil, citrus oils (e.g., limonene, linalool), cinnamon oil, and lemongrass oil, can be found in some topical flea control products. Because these ingredients are derived from plants and touted as natural or organic alternatives to chemical insecticides, many pet owners assume they are very safe. However, both dogs and cats can have serious adverse reactions to some of these ingredients, even when the product is used according to label directions. Side effects can include skin irritation, agitation or lethargy, vomiting, tremors, and seizures,” says the Pet Poison Hotline. Garlic, an ingredient in one of the products, is hazardous to cats and dogs. While some claim the amount of garlic is low enough to alleviate concerns, we would refer pet parents to a veterinarian or the pet poison hotline to determine its safety.

Common Questions about Flea Products:

Our comprehensive Flea & Tick Control For Cats Guide will help you understand what to do in the event of a flea infestation, how to prevent them, and how to care for your pets and your home.

 

  • What is meant by safety in flea products?

By safety, we refer to your cat’s minimum age and weight required to use these products. It is imperative to remember that not all products are alike. Please read the instructions and apply per the manufacturers’ recommendations. Capstar (and like products) require cats and kittens to be four weeks of age and weigh more than 2lbs, while Comfortis requires cats and kittens to be 14 weeks of age and weigh more than 4.1lbs. 

Unlike topical flea medications, you do not need to be concerned with touching your pet following the drug administration, nor do you need to separate your pet from other household pets. 

  • Which products are safe for pregnant cats?

While some products, such as Capstar, CapAction, and PetArmor FastCaps, state they are safe for breeding and pregnant cats, we advise you always to contact your veterinarian for guidance. Your vet can help you assess the risks and benefits so you can make a more informed decision.

  •  My cat has a health condition; which products are safe for her/him?

Please consult with your veterinarian when choosing a product to ensure you have the best guidance possible for your cat’s case.

  •  Do fleas have to bite my cat to die?

Unfortunately, Comfortis, Capstar, CapAction, and PetArmor FastCaps require a flea to bite to release the parasiticide.  

  • I’ve used flea products in the past, but none seem to work. Why?

The most common reason flea products do not work is that pet parents inconsistently administer them. For a flea infestation, it takes a minimum of 90 days to effectively eradicate fleas using not only flea treatments for your pet but also flea treatments for the environment where the cat lives, such as your home. It is simpler, more affordable, and less stressful to be consistent and give Comfortis (or apply a topical flea treatment) monthly. Your cat is counting on you to keep him or her comfortable and free of parasites.