Frontline Plus

Frontline Plus Spot-On


Liquid Spot-on

Active ingredient

Fipronil, (S)-methoprene

Frequency of use

Every 4 weeks

Minimum age/weight

8 weeks (1kg cats / 2kg dogs)


Fleas (adults), fleas (immature), ticks, lice

What is Frontline Plus?

Frontline Plus is a non-prescription spot on flea and tick treatment. It contains Fipronil, an adulticide, and (S)-methoprene, an insect growth regulator. It kills fleas and ticks for 4 weeks after topical application.

What does Frontline Plus do?

Frontline Plus Spot On contains two active ingredients, fipronil, and (S)-methoprene. Let’s break down how they work:

  • Fipronil: This ingredient is a broad-spectrum insecticide and acaricide. Once applied, it quickly spreads across your pet’s skin and hair follicles through the sebum (skin oils). Fipronil targets the nervous system of fleas and ticks, disrupting their normal functioning and killing them.
  • (S)-Methoprene: This is an insect growth regulator. It mimics the juvenile growth hormone of fleas, therefore blocks the actual hormone from working and preventing the development of flea eggs and larvae. By interrupting the flea life cycle, (S)-methoprene helps control and prevent infestations.

Once applied, Frontline Plus Spot On is stored in the oil glands of your pet’s skin, providing a sustained release over time. This ensures continuous protection against fleas and ticks, maintaining a flea-free and comfortable environment for your furry companion.

What is Frontline Plus for?

Frontline Plus Spot On helps control ectoparasites (parasites that live on your pet’s skin) in the following situations:

  • Flea Infestations: If your pet is dealing with a current flea problem, Frontline Plus kills adult fleas, putting an end to the itching and discomfort. It also interrupts the growth cycle of the fleas, getting an infestation under control more quickly than an adulticide-only medication.
  • Tick Control: Frontline Plus kills ticks, preventing potential diseases transmitted by these parasites.

What are the possible side effects with Frontline Plus?

Frontline Plus Spot On is generally well-tolerated, but it’s essential to be aware of potential side effects. These can include:

  • Mild skin irritation and redness: In rare cases, pets may experience mild and temporary skin irritation at the application site. This typically resolves on its own.
  • Hair loss at application site: Some pets might exhibit temporary hair loss at the application site. This is rare and usually cosmetic, with hair regrowth occurring after the treatment period.
  • Excessive scratching: Occasionally, pets may exhibit increased scratching. This is typically a temporary reaction to the application and tends to diminish on its own.
  • Drooling: Some cats may start hypersalivating (drooling) after application. This may be due to licking, so may be prevented by applying the liquid high enough on the back of the neck.
  • Vomiting: Very rarely, vomiting is reported as a side effect.
  • Respiratory signs (unusual breathing): Very rarely, breathing problems have been reported after use.

Remember, these side effects are rare, and the benefits of Frontline Plus Spot On in preventing flea and tick infestations far outweigh the risks. If you have any concerns or notice persistent changes in your pet, consulting your veterinarian will provide reassurance and guidance.

How to give Frontline Plus safely

  • Follow instructions carefully: Always use Frontline Plus exactly as your vet has prescribed, or according to the instructions on the label. This includes the right dose, species, and frequency. You will need to know your pet’s up-to-date weight in order to purchase the correct treatment for them.
  • Check weight and age: Frontline Plus shouldn’t be used in cats or dogs less than 8 weeks of age, unless otherwise recommended by a vet. Cats should weigh at least 1kg, dogs at least 2kg.
  • Never split doses: Always use the right size for your pet. Never try to split a larger dose between several pets.
  • Apply to the back of the neck: Always apply where your pet cannot lick it off. This is usually from between the ears to just above the shoulder blades – the middle of the back of the neck is a good place to put it. 
  • Ensure animals do not lick each other after treatment: If you have pets that groom one another, keep them apart until the product has dried.
  • Do not allow animals to bathe or swim: You shouldn’t bathe animals or allow them to swim for at least 2 days after application, as this washes off the product, damaging the environment and preventing it from working properly for your pet.
  • Check with your vet if your pet is on medications: If your pet is on any medications, you should talk to your vet about the best options for flea prevention.
  • Storage and Handling: Store Frontline Plus according to the instructions on the label, usually in a cool and dry place. Make sure it’s out of reach of children and other pets. Dispose of used pipettes immediately to ensure children do not have access to the product.
  • Report any accidental overdose to your vet immediately: If you have mistakenly given too much Frontline Plus, report it to your vet as soon as you realise the error. They may recommend blood tests, intravenous fluids, or monitoring, depending on the severity of the overdose.
  • Use gloves when applying: Some people have allergies to this product, and it can cause skin irritation. Use gloves when applying.
  • Do not handle pet until application site is dry: Care should be taken not to touch the product, and children shouldn’t be allowed to play with pets until it is completely dry. It’s usually best to apply Frontline Plus in the evening so that it can dry overnight. Pets who are regularly treated should not be allowed to sleep in children’s bedrooms. 

Frontline Plus FAQs

How often should I apply Frontline Plus to my pet?

Frontline Plus should be applied every 4-8 weeks, depending whether you’re wishing to prevent only fleas, or ticks as well. In most cases, monthly application is recommended.

Can I use Frontline Plus on my puppy or kitten?

Puppies and kittens can use Frontline Plus from 8 weeks of age, as long as they meet the minimum weight of 1kg for kittens and 2kg for puppies. Take extra care you are using the right pipette size to avoid overdosing.

Is Frontline Plus effective against all types of ticks?

Frontline Plus is licensed for treatment of infestations with the tick species Ixodes ricinus, Dermacentor variabilis, Dermacentor reticulatus and Rhipicephalus sanguineus. These are the most common tick species in the UK. The way Frontline Plus works means it’s likely to work on all tick species, but this should be confirmed by your vet depending on your specific situation.

Can Frontline Plus be used if my pet has allergies or sensitivities?

Frontline Plus shouldn’t be used if your pet has allergies to fipronil, (S)-methoprene, Butylhydroxytoluene or Butylhydroxyanisole. Allergies to these substances are rare, so this product would be suitable for most allergic pets. If you aren’t sure, you should ask your vet about your pet’s specific situation.

What should I do if my pet licks Frontline Plus after application?

Frontline Plus is bitter to taste, meaning many pets will only lick the area once. They may foam or drool, and become hyperactive. Watch your pet carefully for any signs of other problems, and take them to the vet if they become lethargic, nauseous, or show signs of neurological problems. Depending how much they licked, and how high the risk of fleas is, they may need another product applying – to avoid overdose, this may need to contain different active ingredients, so you’ll need to talk to your vet about the best alternative.

Frontline Plus Datasheet

All drugs have a manufacturer’s datasheet, which gives information about the drug’s use and possible side effects. There is usually one in your Frontline Plus box, but if you have lost it you can click on the button below to be taken on an online version.

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Please note that the information contained herein is provided for informational purposes only. Although it has been written by a vet, we cannot consider the individual nature of your pet’s problems so it does not constitute veterinary advice. If you have questions about your pet’s medication or their health you should contact a vet, who will be able to help.