Flies are not only a nuisance, but can transmit diseases to your horses. MultiFly Feed-Thru Fly Control is one of the most effective fly control solutions on the market, at the cost of only $0.36 per day per horse. This safe, pelleted formula provides 99.9% efficacy at breaking the fly life cycle in the manure of treated horses. Simply feed to your entire barn, and watch the fly population quickly shrink.

How It Works

Step 1: MultiFly is administered to each horse in the barn daily

It's important to feed every horse in your barn to see the best effects. Simply feed alone, or with grain. One scoop/day is sufficient for the average-sized horse.

Step 2: Horse eats MultiFly, and expels it all in their manure

The active ingredient in MultiFly, Novaluron, is a completely safe ingredient for horses. It is not absorbed by the horse, but rather is passed through the digestive tract, into the manure.

Step 3: Manure produced by horse is no longer a viable breeding ground for flies.

Fly eggs that are laid in treated manure will die before developing into flies.

Why use a feed-thru fly control?

1. Shrinks the overall fly population.

While fly sprays can be useful, and we recommend them being used in conjunction with MultiFly, they don't tackle the root of the problem. MultiFly helps cut down the overall number of flies, lessening your dependence on fly sprays.

2. Reduces the risk of fly-borne equine. disease transmission.

Using fly spray alone can be a pain to apply to each horse daily. Even fly sprays that are longer-lasting can be affected by sweat, water, and dirt. MultiFly is as simple as a scoop/day with your horse's normal grain.

3. Easy to administer.

ases such as Pigeon Fever and Equine Infectious Anemia (EIA). Fly control is an important piece of helping to protect your barn..

4. Makes a more enjoyable environment for you too!

No one like seeing their horse suffer from swarms of biting flies, but it's also not pleasant for you and anyone that is around your horses. MultiFly can help make your barn more pleasant for everyone who visits.

MultiFly breaks the fly life cycle so that adult flies can't form

"We have 5 horses ranging in age from 1 to 33, we started MultiFly almost 3 months ago and have been extremely happy with the results! I worried about the effect it would have on our 33 year old pony's digestive system since he has issues to begin with but was pleasantly surprised that he has shown no adverse reactions! All five have been eating it with no problems. There are next to zero flies in the barn making all horses happy and humans impressed! Even out in our paddocks we are seeing way less flies than usual this time of year. Delaware is very low, marshy and sandy with a wide variety of biting fly species. We will continue with MultiFly and have recommended it to all our friends."

-Elena Fierro Wise

"Makes a huge difference in the quantity of pesky flies in and around the barn. A definite must for a pleasant equine atmosphere."
Jrt - Verified Amazon Customer
"This helped knock out a terrible fly problem. I am first time user, but this product worked great & faster then others I've used."
- Sharon Douglas - Verified Amazon Customer
"It's easy to use. Since the pellets are alfalfa and wheat midd-. based, the horses gobble them up."
- Dean Family - Verified Amazon Customer

Which Flies Does MultiFly Target?

MultiFly Feed-Thru Fly Control for Horses specifically targets the common types of flies that reproduce in manure, aiming to interrupt their. life cycle and reduce their population. These flies include the housefly (Musca domestica) and the stable fly (Stomoxys calcitrans). It is important to note that certain species of flies, such as the horse fly and deer fly, do not reproduce in manure but rather lay their eggs near. water sources or moist areas, like marshes or ponds. MultiFly Feed-Thru Fly Control focuses on the fly species that rely on manure for reproduction, making it an effective solution for controlling these specific types of flies..

What is in MultiFly?

Novaluron is the Insect Growth Regulator (IGR) used in MultiFly Feed-Thru Fly Control. All feed-thru fly control products on the market have an IGR. An IGR is an active ingredient that works to disrupt the normal life cycle of the insect.
Novaluron, on the other hand, is a minimal-risk IGR that is not an organophosphate. In a 2015 study, it was shown that Novaluron was 100% effective in preventing the development of house flies and stable flies in the feces of treated horses. Novaluron is so safe they include it in drinking water for mosquito control in many parts of the world.

Made With Safety in Mind

The use of organophosphates for feed-thru fly control in horses should be avoided due to the. potential harm they pose to both the animals and the environment. Unfortunately, there are many products still on the market that use organophosphates as active ingredients
These chemicals have been shown to have detrimental effects overtime on the nervous system and overall health of people and mammals, including neurological symptoms like seizures and weakness, as well as gastrointestinal issues like colic and diarrhea. Long-term exposure to. organophosphates can lead to severe and potentially irreversible health problems in horses.. Moreover, organophosphates can contribute to water pollution and accumulate in the environment, leading to a range of environmental problems.
Therefore, it is essential for horse owners to prioritize the use of safer alternatives for fly. control, such as Novaluron, which is a much better choice for feed-thru fly control in horses,. as it effectively targets insects without harming horses or the environment.

Why MultiFly?

  • Manufactured in-house
  • Safe for horses
  • 99.9% effective at breaking the fly life cycle
  • Easy-to-feed pellets
  • No organophosphates
  • 90-day satisfaction guarantee
Stock Up and Save!
Stock up on MultiFly Feed-Thru Fly Control to ensure consistent and effective fly control for your horses and save on this exclusive deal. Plus, by stocking up on MultiFly Feed-Thru Fly Control, you can save money and time in the long run by reducing the need for other fly control methods like sprays or traps. Don't wait any longer to give your horses the relief they deserve from those pesky flies!

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Identical in Efficacy to Farnam Simplifly at a lower daily cost..

This product is not manufactured or distributed by Farnam Companies Inc.®, the makers of Simplifly®. Simplifly is a registered trademark of Farnam Companies Inc®.

Frequently Asked Questions

Why is MultiFly less expensive than other feed-thru fly control products?

We manufacture MultiFly here in our own facility. Unlike other brands that have to pay a private manufacturer to produce their products, we are able to produce ourselves. The extra savings from this process are passed on to you! 

My dog eats manure. Will my dog be safe if he consumes manure when I am feeding MultiFly to my horses?

We have many MultiFly customers with pets that like to eat manure. However, we are not able to make any claims regarding safety/efficacy for any other animal other than horses. With that being said, Novaluron (the active ingredient in MultiFly) has undergone rigorous safety and efficacy studies, even for food-chain animals, and has been approved for commercial poultry operations. 

When is the best time of year to start feeding MultiFly?

It depends where you live. We recommend feeding a few weeks before you notice flies in the spring. You can start feeding it during fly season, but you may not see as dramatic of results.

Should I remove manure before I start using MultiFly?

Yes. We highly encourage customers to remove all manure from the premises. The goal is to eliminate any non-treated manure where flies could continue to breed. 

Is MultiFly safe?

MultiFly is fully registered with the EPA and has undergone significant efficacy and safety studies in order to be approved by the EPA as a registered product that is safe for equines. 

Can I feed this to other species?

The active ingredient in MultiFly is Novaluron.  This ingredient is widely used in agriculture due to its high safety profile and low toxicity risk.  While this ingredient has been tested in non-equines (e.g., cattle, goats, etc.), we are not able to make any claims about safety/efficacy for any species other than equines.  We recommend that you contact your veterinarian before administering to any other species. 

What insects does MultiFly target?

MultiFly has been proven effective at breaking the fly life cycle of house and stable flies. 

How does this compare to garlic-based products?

Garlic-based supplements for fly control are targeted at only repelling the flies from the horse as its absorbed into the horse. They do nothing for reducing the overall fly population. It is also argued that garlic has insufficient efficacy claims.


MultiFly works by breaking the fly life cycle of flies in the manure of treated horses, thus reducing the overall population. MultiFly is not absorbed into the horse, and does not inherently act as a repellent to the horse itself.

I have a smaller/larger than average horse, how much should I feed?

For the average equine at 1100 lbs or less, feed 1 scoop daily. For especially small animals (e.g. 550 lbs or less) you may feed half a scoop. For equines over 1100 lbs, feed 2 scoops daily.

How does this compare to Simplifly®?

Both are nearly identical in efficacy and safety claims. The main difference is the Insect Growth Regulator (IGR) they both use. MultiFly uses Novaluron, and Simplifly uses Diflubenzuron. Both IGR's do the same thing - they stop larvae in manure from forming into adult flies. However, MultiFly is significantly less, at $0.36 per day, versus $0.46/day for a 10 lb bucket of Farnam Simplifly®.


For horse owners who are currently using Simplifly®and would like to switch over to MultiFly, it is safe to do that immediately.

What if I don't see the results I was looking for?

If you aren't happy with the results of MultiFly, simply reach out to us, and we will be more than happy to make it right with our 100% 90-day satisfaction guarantee.

How do I get free shipping?

To get free shipping, spend $100 or more in a single purchase, and it will automatically be applied!

If I sign up for autoship, can I change or cancel anytime?

Yes - you can change or cancel your autoship anytime by logging into your account, or reaching out to us.

Is Novaluron a urea? Is it the same urea that's found in cattle feed?

Novaluron is a benzophenyl urea, which is not chemically similar to urea found in cattle feed.

Will my horse test if drug tested at an event?

MultiFly contains an Insect Growth Regulator, Novaluron. Novaluron's sole purpose in agriculture is to stop flies from forming their exoskeleton - and thus breaking the life cycle. There are no known sedative effects of novaluron.

We always urge customers to reach out to their respective association if they would like to check. We have many customers in different associations that show while on this product and have never had a reported issue.

Will this affect dung beetles?

The active ingredient in MultiFly is novaluron, which works as a chitin synthesis inhibitor. The exoskeleton of all insects contain chitin. Insects that reproduce directly in manure will likely be affected. 

Will this affect bees?

The active ingredient in MultiFly is Novaluron, which works as a chitin synthesis inhibitor. The exoskeleton of all insects contain chitin. Insects that reproduce directly in manure will likely be affected. Since bees reproduce in their hives, bees are unlikely to be affected.


Novaluron is also not systemic - meaning that it cannot be absorbed by plants. Bees and other pollinators will not ingest novaluron through plants.

Can I garden with manure that has been treated with MultiFly?

The active ingredient in MultiFly is Novaluron. Novaluron is not systemic, meaning that it is not absorbed by the plant from the soil. Plants that are exposed to novaluron (in the soil, compost, etc.) will not have any novaluron content present in leaves, stems, etc. Manure treated with MultiFly is safe for vegetables, fruits, and other vegetation. Novaluron itself is widely used in U.S. agriculture for food crops.


In regards to organic gardening - we ask that you reach out to the USDA for clarification for your operation.

Is MultiFly toxic to aquatic life?

The active ingredient, Novaluron, is moderately toxic to fish and very toxic to aquatic invertebrate organisms (e.g. shrimp, crawfish).


Care should always be taken to prevent manure from entering aquifers and bodies of water - regardless if the manure has been treated with a feed-through fly control product. We'd recommend you reach out to your state extension office for guidance on manure management.

Is MultiFly safe for metabolic horses?

A single-serving of MultiFly is very small at about just 0.88 oz. The pellets are low in nonstructural carbohydrates.


We'd recommend you reach out to your veterinarian if you're concerned. We know of many metabolic horses that have been on the product per their vet's recommendation.

My neighbors also have horses and aren't feeding MultiFly. Will it still work?

The best results are when the entire facility and adjacent facilities are on MultiFly - as it stops flies from producing in all manure. It can be tough when your neighbors aren't on the product, as flies can and do travel between farms. Dependent on their proximity and their manure management, you will likely still see a difference in the fly population, albeit not as much as if you were the only one for miles! 

I have one horse in a boarding facility. Is MultiFly worth feeding?

Unfortunately, MultiFly works best when all horses on the premises are on the product. Since flies would still be able to reproduce in the manure of other horses at the barn, it will be unlikely to make a difference.


Speak to your barn manager about getting a whole-barn program started!

Does MultiFly repel flies from my horse?

No - MultiFly is ineffective towards existing adult flies. MultiFly is not a fly repellant - rather it is an Insect Growth Regulator that stops flies from reproducing in manure.

Is MultiFly carried in retail stores?

Since MultiFly is a newer product, it isn't in a lot of brick & mortar stores - yet. Feel free to let your local store know if you'd like to see the product on the store shelves! They can apply to become a retailer by reaching out to us at

How quickly will I start seeing results with MultiFly?

Some of our customers start seeing results in as little as three days, but most people see significant results in two to four weeks, since that is around the average lifecycle of a fly.

Can I use this in conjunction with fly predators?

Yes! Fly predators attack the pupal stage of the fly and do not eat the manure themselves, so they are unaffected by MultiFly in the manure. For customers that have wet, marshy areas - fly predators can be a great compliment to MultiFly - since MultiFly is only passed through the manure.

Is MultiFly safe for pregnant & nursing mares?

Many of our customers feed MultiFly to pregnant/lactating mares. However, we would recommend getting the opinion of your veterinarian first! 

Is MultiFly safe for breeding stallions?

We'd recommend consulting your veterinarian before feeding MultiFly to breeding stallions.