Solitude IGR Feed Through Fly Preventive

Regularly: $114.99

promotional discount applied.  Cart total will reflect savings.


Sometimes, manufacturers require that products be advertised only at their suggested prices. When we choose to sell these items for less, we display the sale price only in the cart. To see the price, click Add to Cart.

6 lb
Less than $0.45/DAY
(192 day supply)


In Stock. Usually Ships within 24 hours.

20 lb
Less than $0.34/DAY
(640 day supply)


In Stock. Usually Ships within 24 hours.

Shipping weight = 7.00 lbs.


Product Summary:

Solitude IGR™ Insect Growth Regulator Feed-Through Fly Preventive
by Zoetis, formerly Pfizer

Solitude IGR™ (cyromazine) is a non-organophosphate that has been safely used in horses since 2001 and undergone extensive research to prove its effectiveness and safety. It provides feed-through fly prevention and control of house and stable flies in and around horses, horse barns, stables, paddocks, and race tracks. When mixed 1/2 oz. into a horse's ration daily according to the directions, will prevent house and stable fly development.


  • Repeated studies show up to 100% efficacy in inhibiting larvae development
  • Studies have proven it is 99.5% effective against stable flies and 100% effective against house flies with no effect on horses, other mammals or beneficial insects
  • Significant results may be observed within two weeks but the full benefit should be realized within 4-6 weeks of administration as the adult populations die off. Solitude IGR™ is intended for use only in equidae including horses, mules and donkeys.
  • Cyromazine, the active ingredient in Solitude IGR™, is an insect growth regulator that works on the fly's chitin exoskeleton and is very species specific to house and stable flies. As the horse is fed cyromazine, it passes through the horse and is excreted in the manure. House flies and stable flies lay their eggs in the manure and the eggs subsequently hatch into the larval or maggot stage. (Cyromazine has no effect on the chitin of the adult fly.) As the maturing maggots feed on the manure treated with cyromazine, they become unable to successfully develop into adult flies because cyromazine inhibits the proper formation of chitin. The immature stage of the fly dies. Cyromazine has a well documented safety and efficacy profile. It has been extensively evaluated in horses since 2001 as well as intensely studied in other species for more than 20 years. Numerous environmental studies have documented cyromazine's safety for mammals including humans and horses, as well as birds, daphnia, minnows and other indicator species.
  • Once excreted, Solitude IGR™ breaks down to a melamine monomer, a slow release nitrogen fertilizer
  • Greatly reduces the use of neurotoxic pesticide sprays and overhead fly systems creating a healthier environment for horses, staff, and riders
Item Specifications:

Start feeding Solitude IGR™ early in the spring before flies begin to appear and continue feeding throughout the summer and into the fall until cold weather inhibits fly development. In some cases, supplemental fly control measures may be needed in and around paddocks and stables to control adult house flies and stable flies, which can breed not only in manure, but in other decaying vegetable matter or silage on premises. Solitude IGR™ will provide a high degree of fly control and will give the best results when integrated with a well-managed fly control program which includes appropriate sanitary and management practices to reduce the number and size of fly breeding sites.

To maximize the effectiveness of Solitude IGR™, horses must be fed individually. This product is to be fed top-dressed on grain or mixed with the horse's total ration to provide 300mg (one scoop) of cyromazine per horse per day.
Using 1/2 oz. scoop supplied with the product, mix one scoop of Solitude IGR™ in the horse's ration every day.

Do Not Contaminate Water, Food or Feed by Storage and Disposal. Wastes resulting from the use of this product may be disposed of on site or at an approved waste disposal facility. Harmful if inhaled or absorbed through the skin. Avoid breathing dust and contact with skin or clothing. May cause skin sensitization reactions in certain individuals. Wash thoroughly with soap and water after handling. Do not apply directly to water.

Downloadable Resources
MSDS SheetManufacturer Information
Style Item Number Model Number UPC
2 lb SLT101692 002 PFJ 115
6 lb SLT101692 006 10001372 1008721908598
20 lb SLT101692 020 10001373 087219086001

Product Reviews by Customers

4.5 / 5.0
29 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Works well, has reduced fly population significantly
September 24, 2018
1 month ago
This product really helps keep the flies down. I’ve been using it for 5 years. Love it
September 6, 2018
over 2 years ago
This is amazing.
July 13, 2018
3 months ago
Glad I got this again
This works better than others I have tried.
May 29, 2018
5 months ago
Good product, I’ll buy it again!
It does help cut down on the fly population. I use this as well as fly predators. I wish there was something like this for my chickens! This is my second year using it. The horses have no problem eating it on top of their grain. It’s easy to use and safe.
April 8, 2018
7 months ago
We have used this product for 6 years on a ranch with 80 horses. It significantly reduces the fly population and I will continue to feed it.
September 23, 2017
1 year ago
Works great!
This product really keeps the flies at a minimum in our barn. If it weren't for the 2 cows in the pasture next to it, I think it would work even better. We've used it for 3 years and will continue to use it.
June 20, 2017
Product is seems to work very well
I started using this product for the first time in March of this year. It really is working. I have not had the ### of flys that I am used. I have cut way back on using fly spray. My horses are not eaten up by flys. I do have all of my horses on it. I have heard that it may NOT work as well if you have too many animls in one area, like a boarding type facility and ALL animals have to be on it for it to work. My vet recommended this product to me and it works for me.
June 8, 2017
This product is not showing any results in slowing the larva flies
I purchased solitude after trying simplify. Simplify did not work and per the online suggestions people felt that solitude would. I have been using this product for two weeks and still get larva flies within an hour if it's warm outside. There is no phone number on the product for a helpline to find out if I should increase the dosage or what I can do to make this product work. I will not purchase this product again and go back to the old fashion way of fighting flies
April 11, 2017
My Vet Recommends This
I use Solitude 6 months of the year April - September to reduce the fly population around my horses. My equine vet recommends this specific feed-through fly control for horses. It does work and requires such a small amount that it is easy to incorporate into my horses feed.
April 9, 2017
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 10 questions Browse 10 questions and 54 answers
Why did you choose this? Store
I use this year after year and it seems to keep the flies down
Joanne A on Sep 5, 2018
It really works!!!
Kris G on May 22, 2018
I use this year after year and it seems to keep the flies down
Joanne A on Sep 5, 2018
I have used this before with great success in our barn.
Brenda L on Jun 24, 2018
It really works!!!
Kris G on May 22, 2018
Solitude is a great product - it's expensive, but it is worth the cost. It really helps keep the fly population in the barn to a minimum. I've used it for years at my barn.
Kris G on Mar 9, 2018
I especially like that you don't have to adjust the amount added based on horse weight. Along with my Fly Predators, I have really good fly control.
Kathleen R on Jul 26, 2017
been using this for many years now. Wouldn't want to be without it.
Leslie N on Sep 25, 2016
Used before only feed-through that still works AT ALL.
Frank S on Sep 23, 2016
Excellent product for fly control.
Kathleen M on Aug 29, 2016
recommended by my vet. She felt it was the safest feed through.
STEPHANIE M on Jun 8, 2016
the only product that works for fly controll
Andrea K on May 9, 2016
Best Produkt on the market
DANIEL E on Jul 18, 2015
Every little bit helps. One horse gets a little "itchy" when I first start using it, then about a week later he is fine. I use from Easter to Halloween in California.
LYNLEE N on Jul 1, 2015
I have been using this product for 8 years, and it greatly reduces the fly population
KELLY A on Jun 30, 2015
This product works great I have a boarding facility with 48 horses, they are all on it, and we only have about 5% of the flies that we used to. Highly recommend it.
Sara W on Jun 13, 2015
I have been raised around horses and when i bought my horses i tried every feed through, predator flys, as well as old fashion ways, nothing worked. when i'd go visit my mother i noticed the flys where not as bad she has several horses and i only have the two i asked her once if she did any thing special to keep the flys away besides the usual mucking and fly spray. she told me about Solitude IGR and it Works!! I've been using it for years now and hope it never goes away.
Andi K on May 8, 2014
Sounds like it will be the product to do the job for me as I have mares and colts and and various ages of horses.I am willing to try it!
KAY B on May 7, 2014
Got better results than the several other feed through fly control products I've tried. It's expensive but you feed 1/2 the amount of the others which really evens out the price.
JIM E on Apr 28, 2014
have purchased before and satisfied
MICHAEL W on Apr 24, 2014
I worked like a charm last summer. We had a bug free barn!
Mary M on Apr 7, 2014
great product, great price ... free shipping
needed to re-stock for the season
MARCIA G on Mar 19, 2014
Been using this since a few years - one big bucket is enough for an entire year for my two horses. It really keeps the fly population in check. I feed it from March to mid November (SC coastal region).
Regine K on Mar 12, 2014
Excellent product when used correctly. Preparing for spring.
NEANNA G on Feb 16, 2014
I have used this before with great success in our barn.
Brenda L on Jun 24, 2018
Solitude is a great product - it's expensive, but it is worth the cost. It really helps keep the fly population in the barn to a minimum. I've used it for years at my barn.
Kris G on Mar 9, 2018
does this effect using manure in compost in your garden?
janet l on Mar 31, 2015
BEST ANSWER: Solitude IGRâ„¢ breaks down to a melamine monomer, a slow release nitrogen fertilizer. Please check if this is acceptable for garden compost with your County Extension Agent and your veterinarian.
Is this Solitude IGR safe for eggs for human consumption, layer chickens and ducks who eat the fly larvae that have been treated with the Solitude IGR?
HeatherAnne on Mar 23, 2017
BEST ANSWER: Pfizer shows information that studies have proven it is 99.5% effective against stable flies and 100% effective against house flies with no effect on horses, other mammals or beneficial insects. For information about egg-laying chickens, we would have to refer you directly to Pfizer: or phone 800-879-3477.
Can this be fed to all of my horses? Stud, mares in foal, and yearlings
Rita S on Feb 21, 2017
BEST ANSWER: Absolutely! I love this stuff! I have tried everything on the market but nothing works like Solitude.
what is the largest container available?. I used to be able to get a bigger container.
Kathy B on Mar 10, 2016
BEST ANSWER: The largest container available through us is the 20 pound.
My small yorkies often eat horse chips while I'm cleaning stalls. Will this product be detrimental to their health?
A shopper on Aug 30, 2015
BEST ANSWER: I don't know, but I can tell you, that I used this product for 2 years ( switched to fly predators this year) and my dogs ate the "chips" all the time with seemingly no ill effects- I think it worked in their poop too . But, they are much bigger then a yorkie, so he might be a little more delicate. I can't recall their being a warning on the label either. I hope that helps. If I were you- being has he is such a little dog,- I would call the vet and see what they say. It was a very effective product, and I decided to go with the more expensive Solitude, rather then the other ones on the market because i got the impression, after doing a lot of internet "researching", it was safer for the horses and the dogs. HtH
Is this product harmful to dogs or other animals who might ingest the treated manure?
Terry H on Aug 10, 2015
BEST ANSWER: I have 4 horses and over the years have had 5 dogs at one time. I have been feeding Solitude IGR for 4 years. My dogs have the run of the farm and I have never had a problem from the dogs ingesting the treated manure.
Does this have any affect on lice?
leigh a on May 30, 2017
BEST ANSWER: I'm sure it doesn't. It's formulated to kill the fly larvae in the feces. Different life cycle for lice.
What is the shelf life?
Maggie K on Sep 6, 2018
BEST ANSWER: All I can say is I had half a 20 lb bucket left at the end of summer last year. I closed it up and put it away and was glad I had it in the spring. It was available to start for my five horses as soon as I saw the flies appear. I didn't have to wait to order. It seemed to work just fine. Beyond that I don't know. I think you would have to ask the manufacturers that.
What shots do I need to give my donkey?
A shopper on Apr 3, 2015
BEST ANSWER: It depends on many factors. Please contact your local veterinarian.