Does Frontline Repel Ticks

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Frontline is known to pet owners as an effective spot-on product for tick control. The active ingredient Fipronil acts directly on the nervous system of ticks and other blood-sucking pests. Fipronil is a so-called antiparasitic. So to the question: does frontline repel ticks? No, it does not repel ticks, but it kills ticks when they get in contact with it.

How Does Frontline Repel Ticks?

As an antiparasitic, Frontline does kill ticks, fleas, and about all other pests.  The active ingredient Fipronil is fat-soluble and as such is absorbed and stored in the oil glands ( sebaceous glands) which are under the top layer of the skin (epidermis). From here it is slowly released from the glands to the skin and fur.

What is Fipronil?

Fipronil structural formula

Fipronil is an insecticide from the group of phenylpyrazoles, synthetically made organic compounds.

It is a contact poison with a fast, long-lasting, and very reliable effect that kills ectoparasites that are common in pets such as ticks, fleas, lice, Demodex mites, mange mites, and many more.

When a pet treated with Frontline (Fipronil) becomes infested with ectoparasites such as fleas or ticks, they will come into contact with the insecticide as they crawl in the animal’s fur.

Being a contact poison, the active ingredient of Frontline quickly penetrates the parasite’s exoskeleton and begins its action directly on the nervous system of the parasite.

It inhibits certain nerve receptors and blocks transmitter substances (chloride ions) in the transmission of information and thus prevents nerve stimuli, which leads to overstimulation and death of the parasite.

This fipronil-specific inhibition of nerve receptors occurs only in invertebrates, i.e. insects and spinner-like creatures. In mammals, birds, and reptiles, fipronil does not have a comparable strong effect in this regard.

How long does it take for Frontline to work?

When a parasite comes into contact with the skin or fur of the treated animal, the fipronil penetrates the organism of the parasite within just a few hours. It disrupts the nervous system of the attacker and immobilizes it quickly. Fleas or ticks don’t have to bite the pet for Frontline to work, just the contact with fur and skin is enough to be effective. When used as recommended, Frontline kills ticks in about 24 to 48 hours.

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How to use Frontline?

Frontline is available for dogs and cats, all animals in a household should be treated. Frontline should be applied once a month. Part the fur in the neck or between the shoulder blades until the skin becomes visible. Place the pipette tip directly on the skin and empty completely.

  • Pay attention to the correct size, there are different applicator sizes. Choose according to the weight of the pet
  • Part the fur in the neck (somewhere the pet cannot reach) and drip it directly onto the skin
  • The entire contents of the applicator must be applied to the skin so that it protects for the specified period of time
  • Keep the pet away from water for 48 hours and do not bathe it
  • The application must be repeated at regular intervals for optimal protection
  • READ the label and use as instructed

Is Frontline safe?

Studies of Frontline over the years have shown no evidence that Frontline causes cancers in pets. The dose of the active ingredients in Frontline is very low and when used as recommended considered harmless to the pet, but still lethal to fleas and ticks. However, some dogs have been observed to be mildly allergic to Frontline.

Side effects are possible with any kind of medication, as the metabolism of each individual may react differently. Whenever using a medication you need to balance the risk (side effects) with the benefit (preventing tick-transmitted diseases).

Side effects always sound alarming, fortunately, they are very rare. If Frontline is used as recommended it is very safe and effective in keeping your pet tick-free. While some natural methods are better and chemical-free, Frontline is more powerful and kills all ticks on your pet’s skin and fur.


  • Easy to use spot-on preparation
  • Highly effective for about four weeks
  • Available as an application for cats or dogs
  • Comes in different sizes, be sure to pay attention to the pet’s weight
  • Also works against fleas, mites, and other fur parasites


  • Pet is not allowed in the water for two days after use
  • Very toxic to fish and aquatic life
  • Side effects are possible when overdosed (follow instructions)
  • Must be applied regularly (every 4 to 6 weeks)

Frontline offers effective protection against ticks and fleas for your dogs and cats. It is essential to pay attention to the correct dosage, then side effects are rare. As a pet owner, you should weigh the risks and benefits of a tick repellent.


Frontline is available as a spot-on preparation as well as a spray. It is used for getting rid of and the prevention of skin parasites in pets.

  • Spot on: After proper application, the active ingredient is absorbed into the fat layer under the skin and into the sebaceous glands. From here it is continuously discharged (residual effect).
  • Spray: Sprayed directly onto the fur of the pet. Avoid the head and face to prevent inhalation. Less suitable for animals with long, thick fur.  Scares some animals, the pet needs to get used to spraying.

So does frontline repel ticks or does frontline kill ticks?

Frontline kills ticks within 24 to 48 hrs of contact. It does not repel ticks or fleas from clinging onto your pet. But since it kills the parasite very quickly, it prevents infestation. In this way it also prevents tick bite, because it takes a tick several hours to up to 2 days crawling around in search of a suitable bite site, Frontline has likely killed them before they get a chance to bite.

Ticks lurk everywhere in your garden as well as out in nature. When bitten by a tick, removal, observation of the bite, and monitoring the victim for symptoms of tick-transmitted diseases is most important.

Use tick repellents to protect your pets, yourself, and your family from ticks. Even though there is no 100% guarantee of keeping ticks at bay, effective tick control reduces the risk of tick infestation and tick bite. But when bitten you need to know what symptoms to look for and when to worry about a tick bite.


Learn more about Fipronil on the National Pesticide Information Center

More about Fibronil on Science Direct