Flea products for cats (Over-the-counter and Prescription)

When a cat has fleas, you’ll need to apply a flea product that kills the adult fleas (an adulticide). This is an essential part of treatment. But what’s the best treatment to use?

Treatments can be

  • Over-the-counter (available from pharmacies, pet shops, online etc)
  • Prescription only (available from your vet or from pharmacies and online with a valid prescription from your vet)

And there are options for

  • Tablets
  • Spot-on liquids (topical products)
  • Flea collars
  • Liquids

In the following section, we’ll break down all of the flea products available for cats in the UK.

Over-the-counter flea treatments for cats

Many over the counter flea products can be bought without a prescription from pharmacies and pet shops as well as online. Technically, the legal category for these products is either NFA-VPS (which stands for ‘non food animal – veterinarian, pharmacist, or suitably qualified person’) and means the person supplying the drug must have had some training to ensure safe use, or AVM-GSL, which means there are no restrictions on sale. Practically, the ‘suitably qualified person’ training can be taken by anyone, so most pet shops ensure their staff members are suitably trained.


There are only two adult-killing drugs licensed for feline over-the-counter spot-on flea treatments in the UK. These are fipronil and imidacloprid.

Some products also contain (S)-methoprene, which kills some of the immature stages of the flea to allow for faster control.

Fipronil-based products

Fipronil is the most common topical flea treatment in the UK. It’s an active ingredient found in:

  • Frontline Plus, Frontline Combo, Frontline Spray, and Frontline Tri-Act
  • FIPROtec, FIPROtec Combo, and FIPROtec Spray
  • Effipro, Effipro DUO, and Effipro Spray
  • Fipnil
  • Flevox
  • Fleascreen combo
  • Itch
  • Bob Martin Clear Plus

In other words, all of these treatments contain the same adulticide – fipronil. So while it may seem like there’s a lot of choice when you go to the pet shop, most of these contain the same active ingredients and it’s only the branding that varies.

Imidacloprid-based products

Imidacloprid is less common, but still available in most shops. Products that use this drug as the active ingredient include:

  • Advantage
  • Johnsons 4Fleas Spot On
  • Imidaflea

In all cases, there are also prescription-only drugs that contain these active ingredients, but mixed with other drugs (which is why they are prescription-only).

Listen to the audio note to hear more information about fipronil and imidacloprid-based products


The only non-prescription flea tablet ingredient is nitenpyram. It’s the active ingredient in:

  • Capstar
  • Johnsons 4Fleas Tablets
  • Bob Martin Clear One Dose Tablets

This fast-acting insecticide kills adult fleas feeding on your cat within minutes, but only stays in the body for around 24 hours.

It’s really effective at de-fleaing strays before they enter the house, but due to the really short action isn’t suitable for controlling an infestation.

Remember, as soon as fleas have laid eggs, you need to treat for 12-20 weeks, depending on the product you’re using. Doing that with a daily tablet is likely to be ineffective!

Flea collars

Various flea collars are available, and they’re split into ones that kill fleas, and ones that just repel fleas. To treat an active infestation, you’ll need the type that kills fleas. Collars of this type contain

  • Permethrin, and derivatives (deltamethrin, flumethrin)

Permethrin-based collars

Collars that use permethrin as the active ingredient include:

  • Beaphar flea collars (permethrin)
  • Seresto collar (flumethrin with imidacloprid)

Please note that permethrin is fatally toxic to cats in high enough doses so you should never apply a dog product to a cat.

Cat collars should be designed to snap if a cat becomes trapped, to avoid potentially fatal injuries. Check all flea collars have this before applying to your cat.

Flea shampoos

Flea shampoos are usually repellent products – they leave a scent on the coat that is unattractive to fleas. Additionally, they work by physically washing the fleas from the coat.

This is an ineffective technique, as only 5% of a flea infestation are on a cat at any one time. Removing those that happen to be on your cat in order to be shampooed away is a drop in the ocean of an infestation.

In addition, cats tend to dislike baths and you’re likely to regret trying!

Oral liquids

A drug called lufenuron (PROGRAM) acts as a ‘flea contraceptive’, effectively preventing any fleas that jump on your pet from reproducing. It’s available as an oral liquid that is put on your cat’s food.

Because it’s a contraceptive, lufenuron only works well if all animals in the house are on the same drug. Tablets are available for dogs, and there is also a prescription-only injection.

This isn’t a commonly available medication that has ‘fallen out of fashion’ and you may struggle to find it in the UK.

Prescription flea treatments for cats

A huge range of different flea drugs are available as POM-V (which stands for ‘prescription only medicine – veterinary). Like the over-the-counter options, they are available in many forms, but not shampoos or flea collars. They’re more likely to be modern medicines or contain a number of active ingredients which allows them to work on other parasites as well. Let’s take a look at the options for flea treatment available with a prescription.


When it comes to prescription-only medication, spot-ons are still widely used, as they’re simple and easy to apply. These topical treatments may include drugs like our familiar friends imidacloprid, fipronil, and (S)-methoprene, but they’re POM-V because they’re now in combination with other drugs like:

  • Moxidectin (eg Advocate, Moxiclear, Prinovox, Prinocate)

Prescription spot-ons may alternatively include active ingredients like:

  • Fluralaner (eg Bravecto Spot-on)
  • Eprinomectin, Praziquantel and Esafoxolaner (Nexgard Combo)
  • Emodepside, Praziquantel, and Tigolaner (Felpreva)
  • Dinotefuran and Pyriproxyfen (eg Vectra Felis)
  • Selamectin (eg Stronghold, Stronghold Plus, and Evicto)
  • Sarolaner (eg Stronghold Plus)


More recent advances in flea control have been based around spot-ons for cats, as they’re easier to apply. However, there are also some chewable tablets, which most cats seem to take without a problem. The active ingredients that come in tablet form are:

  • Lotilaner (eg Credelio)
  • Spinosad (eg Comfortis)


Lufenuron (PROGRAM) is an injection that prevents fleas from reproducing for 6 months. It used to be common in the UK but many vets no longer stock it.

How do I choose a product?

Deciding on a suitable product for your cat is tricky at first glance, as there seem to be a lot of options. You’ll need to consider:

  • What you’ve used before, and whether it worked
  • Your pet’s other parasite risks – do they need tick protection?
  • How many pets are in the house- is it impractical to take them all to the vet for a prescription?
  • Whether your pet shows signs of flea allergy (FAD)
  • Whether your cat has any medical conditions

Which flea treatment is the best?

There are lots of possible flea treatments, and none is ‘best’ because they all suit different pets differently.

However, we can narrow down options. For non-prescription options, spot-ons are the only good long-term solution. If you’ve previously struggled with a fipronil product, you should try one containing imidacloprid or try a prescription.

Prescription options normally give you more choice. For instance, there are spot-ons available that can provide 12 weeks of continual cover from a single application – a fantastic, easy option. Prescription products may also treat more parasites, and they come with the benefit that a vet can help you choose a product and give you personalised advice. This means they often seem to be more effective, as the product will be individually chosen for your pets.


Whatever you choose, you will need to treat all the animals in the house continually for 12-20 weeks, without a break in cover.

Getting a prescription for a flea product

If you’ve decided that you want a prescription flea product, your next question will be how to get hold of a prescription.

Under UK law, vets must examine a pet in order to write a prescription for them. In some cases, this has already been done – for instance, at a recent vaccination. However, new laws mean that the prescription has to be made at the time of the examination (even if you don’t take the product).

This may mean that your pet was vaccinated last week, but if you declined flea treatment at the time your pet may not have an active prescription. In some cases, this will mean your vet cannot legally prescribe the flea treatment without seeing your pet again.

Once your vet has written the type of product, dose, and frequency to be applied to your cat’s notes, this is now a ‘prescription’. You can either purchase the product from the vet now, or ask for this prescription to be a ‘written prescription’, which means you can take it to another pharmacy or online pharmacy that stocks the medication, and they can get it for you. Written prescriptions may incur a fee.


Only a very limited number of drugs are available without a veterinary prescription, and most of the choice you see is different brands but the same active ingredient. On the other hand, prescription products have a wide variety of active ingredients. If you’ve struggled with non-prescription products in the past, it might be worth trying prescription products – you’ll need to see the vet for this, but then you can usually get a script that lasts a year. Check with your local vet to see what they can offer you.

Key Takeaway

Choosing the drug that suits your pets can be difficult. If you’re stuck, head to your vet, who can write you a prescription or just advise you on which over-the-counter product best suits your needs.