NexGard vs Frontline Plus: Which Flea & Tick Treatment Is Better?

Choosing the right flea and tick prevention for your dog is one of the most important decisions you will make as a pet owner. Two of the most widely recognized names in this category are NexGard and Frontline Plus. Both are trusted by millions of dog owners and recommended by veterinarians, but they work in fundamentally different ways. NexGard is an oral chewable that kills parasites through your dog's bloodstream, while Frontline Plus is a topical solution applied to the skin that spreads across the coat. Each approach has distinct advantages and trade-offs.

In this head-to-head comparison, we break down exactly how these two products differ across every factor that matters: active ingredients, effectiveness, speed of kill, safety profile, convenience, and cost. By the end, you will have a clear picture of which product is the better fit for your dog and your lifestyle.

Quick Comparison: NexGard vs Frontline Plus

Before we dive into the details, here is a side-by-side summary of the key differences between NexGard and Frontline Plus.

How NexGard Works

NexGard is an oral flea and tick preventive manufactured by Boehringer Ingelheim. Its active ingredient is afoxolaner, which belongs to the isoxazoline class of parasiticides. When your dog chews and swallows a NexGard tablet, afoxolaner is absorbed into the bloodstream and distributed throughout the body tissues. When a flea or tick bites your dog and begins feeding, it ingests the afoxolaner, which overstimulates the parasite's nervous system and kills it.

NexGard begins killing fleas within eight hours of administration and achieves greater than 99 percent flea kill within 24 hours in clinical studies. For ticks, the kill time is within 48 hours. The beef-flavored chewable is highly palatable, and most dogs accept it readily as a treat. Because the active ingredient works systemically through the blood, it is not affected by bathing, swimming, or rain, which gives it a significant advantage over topical treatments in terms of consistent protection.

NexGard is a prescription-only medication in the United States, which means you will need to obtain it through your veterinarian. This is partly because afoxolaner carries a label warning about potential neurological side effects, including tremors and seizures, particularly in dogs with a history of seizure disorders. While these adverse events are rare, the prescription requirement ensures veterinary oversight.

How Frontline Plus Works

Frontline Plus is a topical flea and tick preventive manufactured by Boehringer Ingelheim (the same parent company as NexGard). It contains two active ingredients: fipronil, which kills adult fleas and ticks, and (S)-methoprene, an insect growth regulator (IGR) that prevents flea eggs and larvae from developing. This dual-action formula addresses multiple stages of the flea life cycle, not just the adult parasites.

The solution is applied between the shoulder blades, where it spreads across the skin through the natural oils of the coat. Fipronil collects in the oil glands of the skin and is released continuously over the following 30 days. It kills parasites on contact rather than requiring them to bite, which is a meaningful difference from oral treatments. Adult fleas are killed within 12 hours of contact, and the product remains effective for a full month.

Frontline Plus is available over the counter without a prescription, making it one of the most accessible flea and tick treatments on the market. It has been in use since the late 1990s and has an extensive safety track record. However, its topical nature means that it can be affected by frequent bathing or swimming, and there have been reports of reduced effectiveness in some flea populations that have developed partial resistance to fipronil in certain geographic regions.

Effectiveness Comparison

Flea Control

Both NexGard and Frontline Plus are effective at killing adult fleas, but they differ in speed and mechanism. NexGard kills fleas faster, with a demonstrated speed of kill within eight hours compared to Frontline Plus's 12-hour window. In clinical trials, NexGard showed over 99 percent flea efficacy at the 24-hour mark throughout the 30-day dosing period.

Frontline Plus includes the added benefit of (S)-methoprene, which disrupts the flea life cycle by preventing eggs and larvae from maturing. This is an important distinction because it addresses the environmental flea population, not just the parasites on your dog. NexGard does not include an insect growth regulator, though fleas must bite the treated dog to die, which effectively reduces the reproductive population over time.

Tick Protection

Both products kill the major tick species of concern, including the American dog tick, black-legged tick (deer tick), lone star tick, and brown dog tick. NexGard has an additional labeled claim against the Asian longhorned tick. Kill times for ticks are comparable at approximately 48 hours for both products.

One important consideration is that Frontline Plus kills ticks on contact as they crawl through the treated coat, while NexGard requires the tick to attach and begin feeding before the active ingredient takes effect. In areas where tick-borne diseases like Lyme disease are prevalent, this difference in mechanism may influence your veterinarian's recommendation, since contact-kill topicals may reduce disease transmission risk by killing ticks before they feed long enough to transmit pathogens.

Safety and Side Effects

Both NexGard and Frontline Plus are generally well-tolerated when used according to their label directions. However, their safety profiles differ based on their respective delivery methods.

• NexGard side effects: The most commonly reported side effects include vomiting, diarrhea, lethargy, and decreased appetite. The FDA has issued a warning that isoxazoline-class products (including NexGard) may cause neurological adverse events such as muscle tremors, ataxia, and seizures in some dogs. Dogs with a history of seizure disorders should use NexGard only under close veterinary supervision.
• Frontline Plus side effects: Topical reactions are the most common, including temporary skin irritation, redness, or itching at the application site. Some dogs may experience hair loss at the application point. Systemic side effects are rare with topical application because the product works primarily on the skin surface rather than entering the bloodstream in significant amounts.

Always consult your veterinarian before starting any flea and tick prevention, especially if your dog has pre-existing health conditions, is on other medications, or has a history of seizures.

Convenience and Lifestyle Factors

Your daily routine and your dog's behavior patterns should play a significant role in which product you choose.

• Swimming and bathing: NexGard has a clear advantage for water-loving dogs. Since it works systemically, no amount of swimming, bathing, or rain affects its efficacy. Frontline Plus is waterproof after 24 hours, but frequent bathing with harsh shampoos can reduce its effectiveness over the 30-day dosing period.
• Multi-pet households: If you have cats or young children, NexGard eliminates the concern of topical residue transferring to other animals or family members through contact. With Frontline Plus, you should keep the treated dog separated from other pets and children until the application site is fully dry.
• Picky eaters vs. touch-sensitive dogs: Most dogs eagerly accept NexGard's beef-flavored chewable, but some dogs may spit it out or refuse it. Conversely, some dogs are extremely sensitive to having products applied to their skin and resist topical application. Choose the method that aligns with your dog's temperament.
• Prescription access: NexGard requires a veterinary prescription, which means an initial vet visit and ongoing prescriptions for refills. Frontline Plus is available without a prescription at most pet supply stores and online retailers, offering greater convenience for purchasing.

Cost Comparison

NexGard typically costs more per dose than Frontline Plus. The exact pricing depends on your dog's weight class and where you purchase, but as a general guideline, NexGard runs approximately 20 to 40 percent higher per month than Frontline Plus. Over the course of a year, this difference can add up to a meaningful amount, particularly for larger dogs that require higher-dose formulations.

However, price should be weighed against effectiveness and convenience. If Frontline Plus's efficacy is compromised in your area due to fipronil resistance, the lower cost becomes less relevant. Additionally, factor in the cost of a veterinary visit to obtain a NexGard prescription if your dog does not already have an established relationship with a vet. If cost is a significant concern, a pet insurance plan that covers preventive care can help offset the annual expense of flea and tick prevention.

When to Choose NexGard

NexGard is likely the better choice for your dog if:

• Your dog swims, bathes, or gets wet frequently
• You have cats or small children in the home and want to avoid topical residue
• Your dog readily eats flavored chewable treats
• You live in an area where flea populations show resistance to fipronil-based products
• You prefer a mess-free application method with no oily residue
• Your veterinarian specifically recommends an oral isoxazoline product

When to Choose Frontline Plus

Frontline Plus may be the better fit if:

• Your dog has a history of seizures or neurological issues (topical application avoids systemic isoxazoline exposure)
• Your dog refuses oral medications or has a sensitive stomach
• You prefer the convenience of over-the-counter availability without needing a prescription
• Budget is a primary consideration and you need effective protection at a lower cost
• You want dual-action protection that includes an insect growth regulator to disrupt the flea life cycle
• Your dog does not swim or bathe frequently

Can You Use Both Together?

In most cases, using NexGard and Frontline Plus simultaneously is not recommended and is unnecessary. Both products target the same parasites, and combining them increases the risk of adverse reactions without providing proportionally better protection. If you feel that one product alone is not adequately controlling fleas or ticks, consult your veterinarian rather than layering treatments on your own. They may suggest a different product altogether or investigate environmental factors that could be contributing to ongoing infestations.

For a broader comparison of flea and tick treatments beyond these two products, including options for cats, see our best flea treatment for indoor cats guide and our comprehensive flea and tick prevention resource.

Conclusion: Which Should You Choose?

Both NexGard and Frontline Plus are effective, well-established flea and tick preventives with strong track records. The right choice depends on your specific circumstances. NexGard offers faster flea kill speed, complete waterproofing, and mess-free oral administration, making it ideal for active, water-loving dogs in multi-pet households. Frontline Plus provides proven dual-action protection with an insect growth regulator, wider accessibility without a prescription, and a lower price point that makes it an excellent value option for budget-conscious pet owners.

The most important thing is to use whichever product you choose consistently, every month, year-round. Gaps in protection create windows for flea and tick infestations to establish themselves, and once established, they are far more difficult and expensive to eliminate than to prevent.

For a complete overview of all available flea and tick products and how they compare, visit our Flea & Tick Prevention guide.