Weight Building Supplements: Compare
Drs. Foster & Smith Educational Staff

Weight & Muscle Building Supplements for Horses
Many factors influence your horse's weight. Caloric intake, health status, activity level, metabolism, digestive efficiency, temperament, food quality, genetics, and more can all contribute to how much weight your horse gains or loses. But there is no magic formula to determine which component most affects your horse's - or his barn mate's - particular weight.

Thankfully, nutritional supplements are available to help your horse maintain his ideal weight, whether he's hardworking, a performance horse, or a hard keeper. Before starting any weight gain supplement regimen, however, consult your veterinarian. Significant weight loss can signify a serious medical condition.

Product Hard Keeper
by VitaFlex
by AniMed
Weight Builder
by Farnam
Form Granules Powder Powder
Daily Serving 4 oz Approximately 1/2 oz 4 oz
Container Size/
# Servings*
6 lbs:
up to 24
12 lbs:
up to 48
24 lbs:
up to 96
2-1/2 lbs:
up to 80
8 lbs:
up to 32
28 lbs:
up to 112
Base Vegetable Oil,
Animal Fat,
Gamma Oryzanol Grains,
Flax Meal,
Vegetable Fat
Fat (mg/oz) 11,340 0 11,340
Protein (mg/oz) 4,253 0 3,969
Probiotics Yes No No
Additional Ingredients Omega 3,
Omega 6 Fatty Acids
Vitamin E,
Omega 3 Fatty Acids
Gamma Oryzanol
No 1,000 No

* Number of servings is based on daily maintenance dosage for a 1,000 lb horse.

The Ingredients of Weight Gain Supplements
Weight building supplements traditionally contain protein and calorie sources, and may contain certain probiotics for better digestive health, to help your horse gain weight. Some promote muscle development. Combined with a suitable, nutritious diet, and good healthcare, including a comprehensive deworming program, weight gain supplements may benefit your horse. The components of most equine weight gaining feed additives include:

  • Protein is found in every organ and tissue of the body. It is vital for muscle development during growth and exercise. Amino acids are the main building blocks of protein.
  • Fats help increase a feed's energy density, which is the number of calories contained in 100 grams of a particular food. Vegetable oil is the most commonly used fat source in horse feeds.
  • Probiotics are live microorganisms, including bacteria and yeast, which may promote digestive health in your horse. The most common probiotics in horse feeds and supplements include Lactobacillus species (bacteria) and Saccharomyces species (yeast), though some products include additional bacterial species.