Frontline Gold

Written By Mel Lee-Smith
Published: 10/06/2020Updated: 08/30/2021
Frontline Gold for Dogs | Wag!

Frontline Gold is a topical flea, tick, and chewing lice preventative composed of 3 active ingredients to treat existing parasites and prevent new generations. Two of the ingredients in this formula, pyriproxyfen and (S)-methoprene, are chemical "growth regulators". The third chemical component, fipronil, is an insect neurotoxin that causes paralysis and death of fleas, ticks, and many other parasites.

Insect growth regulators help control the flea populations not just on your pet, but also in your home and yard. These chemicals prevent older life stages of fleas from reproducing and stop larvae from hatching. When used properly, these chemicals will stop future generations of insects from reaching adulthood, causing the population to die out over time. 

When applied correctly, the chemicals in Frontline Gold are absorbed by sebaceous glands in your pet's skin and mix with your dog's natural oils. Your pet’s glands will gradually secrete these pesticide-laced oils throughout the fur for about 30 days.


Frontline Gold is available in 4 formulations for different weight groups. The concentration of active ingredients are the same for all weight groups; the difference is the amount of liquid in each tube. Each applicator tube comes pre-measured for the weight group on the box:

  • 5 to 22 pounds:  0.67 ml 

  • 23 to 44 pounds: 1.34 ml

  • 45 to 88 pounds: 2.68 ml

  • 89 to 132 pounds: 4.02 ml

The chemical composition of Frontline Gold for dogs:

  • Fipronil: 9.80%

  • (S)-methoprene: 8.80%

  • Pyriproxyfen: 0.25%

  • Inactive ingredients: 81.15%

Dosage instructions

Frontline Gold comes ready to use with a built-in applicator tip. Press and rotate the cap to remove it. Squeeze the tube's contents directly onto the skin between your pet's shoulder blades and down the length of their spine to the base of the tail. 


A study comparing Frontline Plus with Frontline Gold found that both were 100% effective at eliminating ticks immediately. Still, dogs treated with Frontline Gold had fewer ticks after a month than the dogs given Frontline Plus.

A separate independent study of Frontline Gold and Simparica, as respective treatments for flea infestation in canines, found that both treatments resulted in high flea mortality on days 1 through 6 with no side effects. 

Active ingredients in Frontline Gold

Fipronil, (S)-methoprene, and pyriproxyfen

Side effects

  • Scratching

  • Skin redness and discomfort

  • Stomach upset

  • Loose stools

  • Seizures

  • Appetite changes

  • Hair loss


Frontline Plus is a topical gel, so your dog must not get wet for at least 24 hours after treatment. Swimming or bathing before the medication soaks into oil glands will wash it away and make it ineffective. Avoid letting your dog swim in natural bodies of water within 48 hours of treatment; Frontline Gold is toxic to fish and other marine life forms. 

Wash your hands well after handling and applying this medication. Try not to pet your dog on the areas where you applied the medicine for 24 hours. 

Drug interactions

There aren't many medications that interfere with the effectiveness of Frontline Gold. However, you should ask your vet before combining this medication with any other oral, topical, or wearable pesticide treatments. Many pesticides contain similar ingredients and may lead to an accidental overdose

Allergic reactions and sensitivity

Reach out to your vet if your dog exhibits signs of an allergic reaction when taking this medication. Drug allergies usually manifest as scratching, swelling, and skin redness, but more serious side effects like trouble breathing can occur.

Some dogs experience hypersensitivity if they groom themselves soon after topical flea treatment. Signs of sensitivity from Frontline Gold ingestion include:

  • Loss of coordination

  • Heaving

  • Vomiting

  • Excessive drooling

Ingesting topical flea treatments can cause alarming reactions but typically won't cause long-term effects. Call your vet if you suspect your dog has ingested this medication. 

Frequently asked questions

How long does Frontline Gold last for dogs?

When applied correctly, the active ingredients in Frontline Gold should kill fleas continuously for 30 days. 

How many doses of Frontline Gold for Dogs are in a box?

The 6-month supply contains 6 application tubes, whereas the 3-month supply has 3.

How long should I wait to bathe my dog after treating them?

Since it's a topical treatment, you shouldn't bathe Fido for at least 24 hours after using this medication. Breaking out the shampoo before then will wash away the chemicals before they completely distribute through your dog's coat and skin

What's the difference between Frontline Plus and Frontline Gold for dogs?

Frontline Plus doesn't contain pyriproxyfen, the ingredient in Frontline Gold that kills eggs and stops larvae from developing to maturity. 

Is Frontline Gold safe for puppies?

Frontline Gold is safe for pups older than 8 weeks.

Should I store Frontline Gold in the fridge?

No. It's best to store unopened tubes at room temperature in a dark area. This medication contains flammable ingredients, so do not store or apply it near an open flame. 

Does Frontline Gold get into the bloodstream?

This medication is absorbed into the dog's sebaceous glands, not into the bloodstream. 

Can I use Frontline Gold for dogs on cats or rabbits?

Never use this medication on any animal that isn't a canine. Frontline Gold for dogs contains ingredients that can cause deadly reactions in felines and rabbits. Use Frontline Gold for cats if your feline needs a flea preventative.

Why are flea preventatives so important?

Besides being a nuisance, fleas spread diseases (including the bubonic plague and typhus) and parasites (like tapeworms) to their hosts.

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