Tell the Difference Between Frontline Gold and Frontline Plus

Frontline Gold and Frontline Plus are two flea and tick treatments from the same manufacturer (Boehringer Ingelheim, formerly Merial). They look similar at the pet store but contain different active ingredients and offer different kill speeds and protection profiles.

Frontline Plus is the older and more well-known product. It contains fipronil (kills adult fleas and ticks) plus (S)-methoprene (an insect growth regulator that prevents flea eggs and larvae from developing). It’s been the gold standard for spot-on flea treatment since the 2000s.

Frontline Gold is the newer, upgraded version. It contains the same fipronil + (S)-methoprene as Plus, PLUS pyriproxyfen (another insect growth regulator). The added third ingredient provides faster adult flea knockdown (within 30 minutes per the manufacturer) and double-acting flea growth control.

What Frontline Plus is

Frontline Plus is the long-standing flea and tick treatment from the Frontline brand, used for over 20 years on dogs and cats.

Defining traits of Frontline Plus:

• Manufacturer: Boehringer Ingelheim (formerly Merial)
• Form: topical (spot-on) liquid
• Active ingredients: fipronil + (S)-methoprene
• Kills: adult fleas, adult ticks, all flea life stages (eggs, larvae)
• Application: monthly
• Protection: 30 days against fleas; 30 days against ticks
• For: dogs (over 8 weeks) and cats (over 8 weeks)
• Available sizes: by weight (small, medium, large, extra large)
• Storage: room temperature
• Price: $40-65 per 3-month supply (varies by pet size)

How Frontline Plus works:

• Fipronil kills adult fleas on contact (target nervous system)
• (S)-methoprene is an IGR (Insect Growth Regulator)
• The IGR prevents flea eggs from hatching
• Also stops flea larvae from developing
• Spreads through the dog’s natural oils within 24 hours
• Waterproof after about 24 hours

What it kills:

• Adult fleas (within 12-24 hours)
• All four tick species in the US
• Chewing lice (some strains)
• All flea life stages (eggs, larvae, pupae)

Per the Frontline FAQ page, Frontline Plus has been the brand’s flagship product since the early 2000s. It’s the most widely-used spot-on flea/tick treatment in many veterinary practices.

What Frontline Gold is

Frontline Gold is the newer, upgraded formulation of Frontline. It includes everything in Plus but adds a third active ingredient for faster kill and additional protection.

Defining traits of Frontline Gold:

• Manufacturer: Boehringer Ingelheim
• Form: topical (spot-on) liquid
• Active ingredients: fipronil + (S)-methoprene + pyriproxyfen
• Kills: adult fleas (faster), adult ticks, all flea life stages
• Application: monthly
• Protection: 30 days against fleas; 30 days against ticks
• For: dogs (over 8 weeks); also a separate Cats version
• Faster kill: starts killing fleas within 30 minutes (per manufacturer)
• Available sizes: by weight (small, medium, large, extra large)
• Price: $50-80 per 3-month supply

How Frontline Gold works:

• Fipronil kills adult fleas (same as Plus)
• (S)-methoprene prevents flea egg/larvae development (same as Plus)
• Pyriproxyfen ALSO prevents flea egg development (double IGR action)
• Faster knockdown than Plus
• Designed to combat fipronil-resistant fleas

What it kills:

• Adult fleas (faster than Plus, within 30 minutes)
• All flea life stages (eggs, larvae, pupae)
• Adult ticks (American Dog, Brown Dog, Lone Star, Deer)
• Chewing lice
• More effective against resistant fleas

Side-by-side comparison

The clearest way to see the differences is feature by feature:

The upgrade from Plus to Gold is mainly about pyriproxyfen. The added ingredient delivers faster kill and improved efficacy against resistant fleas.

Active ingredients explained

Fipronil:

• Kills adult fleas and ticks
• Acts on insect nervous system (selective for invertebrates)
• Has been used since the 1990s
• Some flea populations have developed resistance over time
• Spreads through dog’s coat oils

(S)-methoprene:

• Insect Growth Regulator (IGR)
• Prevents flea eggs from hatching
• Stops flea larvae from developing into adults
• Synthetic version of natural insect hormone
• Doesn’t kill adult fleas

Pyriproxyfen (in Gold only):

• Another Insect Growth Regulator
• Different mechanism than (S)-methoprene
• Faster-acting on flea life stages
• Also prevents flea reproduction
• Adds redundancy if one IGR doesn’t catch all eggs

The combination of three ingredients in Gold provides multiple lines of defense against fleas at all life stages.

Per the Frontline for Dogs page, the brand offers different formulations for different needs. Frontline Plus is the established standard; Frontline Gold is the upgraded version.

Speed comparison

Frontline Plus speed:

• Begins killing adult fleas: 4-12 hours after application
• Kills 95%+ of fleas within: 24 hours
• Kills 100% of fleas within: 48 hours
• Egg/larvae prevention: continuous through 30-day cycle

Frontline Gold speed:

• Begins killing adult fleas: within 30 minutes (per manufacturer)
• Kills 100% of fleas within: 12 hours
• Egg/larvae prevention: continuous through 30-day cycle
• Faster overall reduction in flea population

The faster kill speed of Gold is its main advantage for pets currently with active flea infestations. For pets with no current fleas (just monthly prevention), the speed advantage is less critical.

Application

Both products are applied the same way:

For dogs:

1. Part the hair between shoulder blades (above where pet can lick)
2. Apply entire contents of tube
3. Don’t bathe pet for 24 hours after
4. Don’t pet/handle treated area for 24 hours
5. Reapply monthly

For cats:

1. Part hair at base of skull
2. Apply entire contents of tube
3. Same precautions as dogs
4. Don’t use dog product on cats (different formulations)

Both products spread through the pet’s natural oils within 24 hours and provide 30 days of protection.

Pricing comparison

Approximate pricing for 3-month supply:

Frontline Gold is typically $10-15 more than Frontline Plus per 3-month supply. The premium reflects the additional active ingredient and faster kill claim.

When to choose each

Choose Frontline Plus if:

• Your pet doesn’t have a current flea problem
• You want the established, proven formula
• Cost is a factor
• Your pet has been on Plus successfully
• You’re using it for prevention only

Choose Frontline Gold if:

• Your pet currently has fleas
• Faster kill speed matters to you
• Fleas in your area show fipronil resistance
• You want the most effective formulation
• The cost premium is acceptable

For someone unsure: ask your veterinarian. Some areas have more flea resistance than others. Vets in heavy-resistance areas often recommend Gold over Plus.

Common confusions

A few things people often get wrong:

• Frontline Gold and Frontline Plus are NOT the same product. Gold has an additional active ingredient.
• Frontline Plus does NOT kill fleas in 30 minutes; that’s Gold’s claim.
• “Frontline” alone (the older “spot on”) was discontinued; Plus replaced it.
• Frontline Shield is yet another product, with even different active ingredients.
• Both Plus and Gold work against the same tick species; tick protection is similar.
• “Frontline Top Spot” is the old version of Frontline (without methoprene); not commonly sold now.
• Brand-name Frontline is the same as generic versions of fipronil + methoprene combinations.

Frontline product line overview

Frontline brand has multiple products:

• Frontline Spray (older spray formulation)
• Frontline Top Spot (older spot-on, mostly discontinued)
• Frontline Plus (most common, fipronil + methoprene)
• Frontline Gold (newest, fipronil + methoprene + pyriproxyfen)
• Frontline Shield (newer, fipronil + permethrin + pyriproxyfen + methoprene)

Frontline Shield includes permethrin (kills fleas and ticks) for extra fast kill but is NOT safe for cats. Gold is safer for both species.

How to switch products

If switching from Plus to Gold (or vice versa):

• Apply the new product on the next monthly application
• No need for special transition
• The pet’s body will adjust naturally
• Don’t apply both at once

Side effects of either product:

• Skin irritation at application site (mild, common)
• Hair loss at application site (rare)
• Behavioral changes (rare)
• Vomiting if pet licks the application area (uncommon if applied correctly)

Severe reactions are rare but possible. Contact veterinarian if your pet shows unusual symptoms.

Manufacturer information

Boehringer Ingelheim Animal Health is one of the largest pet health companies in the world:

• Acquired Merial (Frontline’s original maker) in 2017
• Headquartered in Germany
• Veterinary products in 150+ countries
• Other Frontline products and other brands (Apoquel, NexGard)

The Frontline brand has been a leading flea/tick treatment since the late 1990s.

How to choose

For routine prevention:

• Frontline Plus is sufficient for most pets
• Apply monthly
• Cost-effective

For active flea problems:

• Frontline Gold is the better choice
• Faster knockdown
• Better against resistant fleas

For severe infestations:

• Combine Frontline with environmental treatment (vacuum, washing bedding, etc.)
• Consider veterinary advice for additional treatment

For cats specifically: only use cat-formulated versions. Dog formulations can be toxic to cats.

at the end

Frontline Plus contains fipronil (kills adult fleas/ticks) plus (S)-methoprene (prevents flea egg/larvae development). It’s been the standard since the early 2000s. Frontline Gold contains the same two ingredients plus pyriproxyfen (a second insect growth regulator). The added IGR provides faster adult flea knockdown (within 30 minutes per manufacturer) and double-acting flea growth control.

Both apply monthly, both protect against fleas and ticks for 30 days, and both spread through the pet’s coat within 24 hours. Frontline Gold costs $10-15 more per 3-month supply.

For pets with current fleas or in areas with resistant flea populations: Frontline Gold. For routine prevention: Frontline Plus is sufficient. Both are made by Boehringer Ingelheim under the Frontline brand.