Do you have a horse that has trouble putting on pounds no matter how much you feed it? Your horse has a clean bill of health and has been cleared of parasites or any teeth issues. So, what is the best weight gain supplement horses need to stay in optimal shape?

Hard keepers are more common in the equine world than you might guess. According to experts, you can help a horse gain weight by feeding a diet high in fat and fiber. These are energy sources the equine digestive system can best digest and utilize.

We selected 10 weight gain supplements for horses and reviewed them based on ingredients and quality as well as reported customer results.

10. Manna Pro Cool Calories 100 Fat Supplement for Horses

Manna Pro Cool Calories 100 Fat Supplement for Horses

 Ideal for: Underweight horses, hard-keepers, and performance horses 

At nearly 100% vegetable fat composition, this supplement is similar to dressing your horse’s food with corn oil. It provides a non-messy solution to increasing your horse’s caloric intake without the dangers of high grain consumption. It also provides fat sourced from the highest-quality vegetable oils.


  • No concerns about feeding with fortified grains or forage
  • Dry – easy to clean, no oily residue
  • Highly palatable
  • Inexpensive


  • Can go rancid once opened

9. Formula 707 Daily Fresh Packs Equine Supplements

Formula 707 Daily Fresh Packs Equine Supplements

 Ideal for: Mature horses, all breeds 

Corn and plant by-products in Formula 707 Weight Gain contribute to a composition of 14% protein, 8% fiber, and 35% fat. Largely a fat supplement, it provides a way for horses to increase caloric intake while still retaining the focus required for work. Formula 707, as with other products in its line, features a synergistic relationship among ingredients to improve metabolism.


  • Convenient individual packaging keeps product fresh and protected from sunlight and moisture
  • Highly palatable – apple flavor
  • Balanced approach – moderately high levels of fiber and fats with protein for muscle support


  • Contains molasses and unidentified plant products

8. Gastromend


 Ideal for: Adult horses suffering from or at risk of gastric ulcer syndrome and frequent minor episodes of colic 

The best horse feed for weight gain may very well be a supplement that addresses a known pervasive cause of chronic weight loss. As many as 60 out of 100 show horses are affected by stomach ulcers, with the figure for racehorses at almost 90%. Performance horses may fail to maintain body weight because of an undiagnosed gastric ulcer.

Gastromend addresses acidification in the stomach and hindgut that occurs in horses from heavy grain diets and the stress of training, transportation, and stall confinement.


  • Does not disrupt normal acid production like medications
  • Cost-effective means of managing equine stomach ulcers
  • Heals lining of the horse’s stomach – increases collagen and fibronectin
  • Natural ingredients


  • Use for weight gain is limited if a horse is not at risk of developing ulcers

7. DAC Bloom

DAC Bloom

 Ideal for: All breeds and ages of horses 

Bloom is made up of 35% fat with its incorporation of soybeans and flax. Soybeans also provide protein. The essential amino acid methionine and lysine help improve the protein quality of your horse’s food. Lysine specifically, may help performance horses build muscle. The remainder of Bloom is composed of vitamins and trace minerals.


  • Chelated trace minerals
  • Soybeans extruded – highly digestible feed
  • Uses organically sourced minerals


  • Has lower fat content than similar supplements

6. Vita Flex Hard Keeper Solution Horse Supplement

Vita Flex Hard Keeper Solution Horse Supplement

 Ideal for: Thin horses of all breeds and performance and show horses 

Comprised of oil from corn, soybean, and flax, Vita Flex provides about 14% protein and 40% fat in its fuel supplement. For horses who struggle to maintain an ideal weight, it gives you a means to add calories to your horse’s diet without her becoming hot or unmanageable.



  • A few horses do not tolerate it – diarrhea reported; may need longer adjustment period than other fat supplements

5. Farnam Weight Builder

Farnam Weight Builder

 Ideal for: Horses that need to gain weight and horses that need to decrease grain consumption 

Feed experts have known for a long time the benefits of vegetable oils on a horse’s coat. Farnam Weight Builder is 40% fat and has added calcium. Therefore, when mixed with standard feeds it does not throw calcium:phosphorus ratios out of balance. It is easily metabolized and encourages both weight gain and maintenance.


  • High in fiber and fat
  • Highly concentrated formula doubles calories in rations without risks associated with high-grain diets
  • Lower doses still benefit the coat, mane, and tail


  • Some owners report it makes their horses hot
  • Uses corn oil

4. Horse Guard Super Weight Gain

Horse Guard Super Weight Gain

 Ideal for: Growing horses under a year and hard-keepers, breeding stallions, and reputably hot breeds like Thoroughbreds, Arabs, and Saddlebreds  

Certified equine nutritionists have hand-selected its ingredients to ensure they are bio-available for horses. A soybean-based product, Horse Guard provides support for weight gain through protein and fat. Its blend of yeast and probiotics supports digestion and nutrient assimilation.

Although the volume you have to give seems high, horses eat it without argument when mixed with regular feed.


  • Proprietary blend of vitamins and minerals
  • Probiotics and prebiotics
  • Soybeans provide a cool energy source, ideal for horses prone to hyperactivity


  • Volume you give is higher than similar products

3. Manna Pro Senior Weight Accelerator for Horses

Manna Pro Senior Weight Accelerator for Horses

 Ideal for: Horses over 10 years old or performance horses of any age 

This energy-packed supplement is composed of 80% fat in the form of flax. Although formulated with senior horses in mind, it is also great for athletes who have trouble maintaining condition.

Labelled a weight gain accelerator, it facilitates healthy increases in body condition score over several weeks. Moreover, it supplies probiotics which are vital in gut health and thus nutrient absorption and body condition.


  • Probiotics supplemented
  • Affordable
  • Uses very low volumes


  • Variable palatability

2. Focus Source

Focus Source

 Ideal for: All breeds of horses who need a nutrient boost 

Many Senior and performance equine feeds and supplements work well as the best horse feed for weight gain because they increase fat content in their formulations. Focus uses flax and seaweed to provide a good balance of Omega-3 and Omega-6 fatty acids and digestible protein.


  • Proprietary blend of micronutrients
  • High in fat and fiber
  • Comes in a weight and senior formulation also
  • Uses chelated minerals


  • High in iodine – follow dosing instructions exactly

1. Adeptus Nutrition Gleam & Gain Supreme 60

Adeptus Nutrition Gleam & Gain Supreme 60

 Ideal for: Show horses, horses requiring nutrient supplementation  

Made up of 60% fat from highly digestible sources, Gleam and Gain is a safe weight gain feed to add extra calories. It is also an exceptional conditioner for your horse’s coat, mane, and tail. Adeptus incorporates rice bran, soybean oil, ground flax, and DHA into a blend complete with nutrient-rich seaweed and digestive aids like yeast cultures.

Gleam and Gain is unique in providing medium-chain triglycerides like those present in coconut oil. These oils supply high levels of useable energy. They are believed to help horses to gain weight because breaking them down does not require transport nor burn many calories.


  • Medium chain fatty acids
  • Variety of types of oils – supply different needs
  • DHA – docosahexaenoic acid; uncommon in equine supplements; usually horses must produce it by converting oils from grains or forage
  • No alfalfa or sugar – truly cool calories


  • Has a preservative


After compiling this list and examining benefits and analyzing ingredients, we determined Adeptus Nutrition’s Gleam & Gain Supreme 60 is the best horse feed for weight gain. It features additional calories as fiber from rice bran, soybean oil, ground flax, the most easily digestible macronutrient for equine digestion, and 60% fat for rapid weight gain.

Furthermore, it is better to feed a well-rounded balanced food with natural ingredients rather than supplements if possible. Gleam & Gain Supreme 60 doesn’t come cheap but can serve as grain and forage simultaneously.

What are your experiences with a thin horse that will not gain weight? Feel free to leave comments on any feeds or supplements we might have left out. You may help us discover an alternative best weight gain supplement for horses we don’t know about.