Vitamins & Supplements

The Best Horse Weight Building Supplements

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Our picks are based on Amazon bestseller rankings, Amazon customer ratings, and product availability. We update our recommendations regularly to ensure accuracy.

Maintaining optimal weight in horses is crucial for their overall health, performance, and well-being. Weight building supplements can be a valuable tool for underweight horses or those recovering from illness. Choosing the right supplement ensures your horse receives the necessary nutrients for healthy weight gain without compromising their digestive health.

No. 1
Manna Pro Weight Accelerator Horse Supplement, Meal Topper, Omega-3, 8 lb
  • HIGH FAT AND CALORIE LEVELS: Manna Pro Senior Weight Accelerator is specially formulated with high fat and calorie content to help senior horses gain and maintain a healthy body condition, supporting energy needs and overall vitality in older horses.
  • OMEGA-3 FATTY ACIDS FOR SKIN & COAT: Senior Horse Supplement contains flaxseed-derived Omega-3s to support skin hydration, reduce dryness, and promote a glossy coat. Helps aging horses maintain healthy skin, improved coat condition, and vitality.
  • FORMULATED FOR SENIOR HORSES: Tailored nutrition for aging horses with probiotics for digestion, biotin for hoof strength, & controlled starch levels to support metabolic health—delivering balanced energy, immunity, & joint mobility in one great...
  • ESSENTIAL VITAMINS & ANTIOXIDANTS: Packed with vital vitamins, antioxidants that support a healthy immune system & help protect senior horses from oxidative stress, promoting overall wellness, vitality & resilience to keep them feeling their best.
No. 2
Manna Pro Cool Calories 100 Horse Supplement, High-Calorie, 8 lb Bag
  • HIGH IN FAT: Contains 99% fat, which is an excellent source of calories and contains more than two times the energy of carbohydrates
  • COOL ENERGY: High calorie density of Cool Calories 100 provides cool, focused energy for performance horses
  • WEIGHT AND BODY CONDITION: Concentrated source of calories supports healthy weight gain and body condition for underweight horses and hard-keepers and reduces the need to feed more grain
  • FATTY ACIDS: Contains fatty acids to support desirable skin and glossy coat condition
No. 3
Formula 707 MuscleMx Muscle Supplement for Horses, 3 lb, 32 Servings
  • Empower your horse's metabolism to build optimum definition and muscle mass.
  • Combines four natural ingredients that synergistically encourage muscle-building metabolic reactions.
  • Lysine, an amino acid, aids in developing muscle-building proteins; Gamma oryzanol encourages weight gain and muscle formation.
  • Creatine helps supply energy to muscle cells by stepping up production of ATP; Ornithine-A-Ketoglutarate (OKG) helps the body bypass metabolic processes that prevent new muscle development.
SaleNo. 4
Formula 707 Weight Gain Crumble for Horses, 7 lb – Calorie-Rich Support
  • WEIGHT SUPPORT: Establish and maintain a healthy weight while improving muscle tone and energy.
  • PALATABLE CRUMBLES: Highly palatable, calorie-rich supplement formulated to help all types of horses maintain a healthy metabolism. Please note these are NOT pellets.
  • COMPREHENSIVE SUPPORT: Vegetable fat provides easily digestible calories and increases your horse’s overall energy, and high-quality protein provides essential amino acids necessary for the body to build muscle.
  • MADE WITH FIBER: Fiber helps keep the digestive system working smoothly.
No. 5
Horse Guard Super Weight Gain 10 lb – 3-in-1 Horse Weight Gain Supplement with Full-Fat Soy, Probiotics...
  • 3-IN-1 FORMULA FOR TOTAL SUPPORT: Combines full-fat extruded soybeans, probiotics, and Horse Guard’s vitamin-mineral package into one powerful horse weight gain supplement for healthy weight, coat, and digestion.
  • VISIBLE RESULTS FOR HARD KEEPERS: Ideal for senior, rescue, or underweight horses; promotes safe, healthy weight gain while improving energy and topline. The go-to weight builder for horses needing extra care.
  • BETTER COAT, BETTER CONFIDENCE: Extruded soy improves coat shine and skin health. Helps your horse look and feel better from the inside out with a high-quality horse feed supplement that makes results visible.
  • DIGESTIVE SUPPORT & IMMUNE DEFENSE: Prebiotics and probiotics boost gut health and nutrient absorption, while 1,500 IU of Vitamin E per dose supports a strong immune system – ideal for stressed, recovering, or sensitive horses.
SaleNo. 6
Formula 707 Weight Gain Crumble Fresh Packs for Horses, 28-Day Supply
  • Establish and maintain a healthy weight while improving muscle tone and energy with a highly palatable, calorie-rich supplement formulated to help all types of horses maintain a healthy metabolism
  • Vegetable fat provides easily digestible calories and increases your horse's overall energy, and high-quality protein provides essential amino acids necessary for the body to build muscle
  • Daily Fresh Packs are sealed to keep out oxygen, moisture and sunlight, and are convenient for traveling, events and daily use in your feeding regimen
  • Accurate, pre-measured packs are convenient and easy to use
No. 7
Farnam Weight Builder Weight Support Supplement for Horses, 30 Day Supply
  • HELPS MAINTAIN OPTIMAL WEIGHT AND BODY CONDITION with a nutritionally balanced high-fat formula.
  • CONTAINS 50% FAT to provide more calories than equal weights of grain, so less volume needs to be fed.
  • PROVIDES EASILY DIGESTIBLE CALORIES WITH NO SUGAR ADDED to safely add calories without the risk of digestive upset.
  • HELPS MAINTAIN HEALTHY SKIN AND A GLOSSY COAT with omega-3 fatty acids from flaxseed meal and heat stabilized rice bran.
No. 8
100-Day Supply Equinety Horse XL Powder Horse Supplement with Amino Acids
  • HIGH-PERFORMANCE EQUINE NUTRITION - Horse XL can help boost horse injury repair, especially in working and performance horses. Horses of all ages and sizes, including pregnant mares, can use our coat defense for horses. It's a must-have for supporting...
  • VETERINARIAN-APPROVED SUPPLEMENT – Horse XL contains a proprietary blend of branched essential amino acids which are the building blocks of protein. Our horse weight gain supplement is necessary for strength and muscle repair.
  • PURE AMINO ACIDS SUPPLEMENT - Equinety Horse XL joint supplement for horses is made in the USA, 100% natural, and non-GMO. It does not contain fillers, soy, sugar, starches, or artificial flavors - a formula safe for horses.
  • HELPS ENHANCE HORSE'S LIFE - Our horse feed can help improve mental focus and responsiveness. It's also a digestive, immune system, and horse joint supplement. Make it a part of your equine supplies and see your horse improve over time.
SaleNo. 9
Formula 707 MuscleMx Muscle Supplement for Horses, 10 lb, 106 Servings
  • Empower your horse's metabolism to build optimum definition and muscle mass.
  • Combines four natural ingredients that synergistically encourage muscle-building metabolic reactions.
  • Lysine, an amino acid, aids in developing muscle-building proteins; Gamma oryzanol encourages weight gain and muscle formation.
  • Creatine helps supply energy to muscle cells by stepping up production of ATP; Ornithine-A-Ketoglutarate (OKG) helps the body bypass metabolic processes that prevent new muscle development.
No. 10
Farnam Weight Builder Weight Support Supplement for Horses, 90 Day Supply
  • HELPS MAINTAIN OPTIMAL WEIGHT AND BODY CONDITION with a nutritionally balanced high-fat formula.
  • CONTAINS 50% FAT to provide more calories than equal weights of grain, so less volume needs to be fed.
  • PROVIDES EASILY DIGESTIBLE CALORIES WITH NO SUGAR ADDED to safely add calories without the risk of digestive upset.
  • HELPS MAINTAIN HEALTHY SKIN AND A GLOSSY COAT with omega-3 fatty acids from flaxseed meal and heat stabilized rice bran.

Last update on 2026-10-07 / Affiliate links / Images from Amazon Product Advertising API

How to Choose the Best Horse Weight Building Supplements

Understanding Your Horse's Needs

Before purchasing any supplement, assess why your horse is underweight. Is it due to poor appetite, digestive issues, increased metabolic rate, or insufficient calories in their diet? Consulting with a veterinarian is essential to rule out underlying medical conditions and determine the best course of action. They can help identify specific nutritional deficiencies that a supplement should address.

Key Ingredients to Look For

Look for supplements rich in essential fatty acids, often derived from sources like flaxseed or oils, which provide calorie-dense energy. Protein is vital for building muscle mass, so ingredients like amino acids (lysine, methionine) are beneficial. Prebiotics and probiotics can support gut health, ensuring efficient nutrient absorption, which is fundamental for weight gain. Yeast cultures can also aid digestion and nutrient utilization.

Forms and Administration

Supplements come in various forms, including powders, pellets, and liquids. Powders are often mixed into feed, which is convenient for most horses. Pellets can also be mixed in or fed separately. Liquids might be easier for horses with picky appetites or those who are difficult to get to eat supplements mixed in their feed. Consider which form will be most readily accepted by your horse.

Evaluating Supplement Quality and Safety

Choose products from reputable brands that clearly list all ingredients and their quantities. Look for third-party testing certifications, such as those from NSF International or USP, which verify product purity and potency. Ensure the supplement is specifically formulated for horses and avoid products with unnecessary fillers or artificial ingredients. Check the expiration date to ensure freshness and efficacy.

Comparison Tips

When comparing products, prioritize those with scientifically backed ingredients known for promoting healthy weight gain. Consider the palatability, as a supplement is only effective if your horse will consume it consistently. Read reviews from other horse owners to gauge real-world effectiveness and ease of use. Always compare the nutritional profile and ingredient list against your horse's specific dietary requirements as advised by your veterinarian.

Frequently Asked Questions

How quickly can I expect to see results from a weight building supplement?
Results can vary depending on the individual horse, the severity of underweight, and the supplement's formulation. Typically, noticeable changes may take several weeks to a few months of consistent use. It's important to monitor your horse's condition and consult your vet if you have concerns.
Can I give my horse a weight building supplement if they are already on a balanced diet?
Yes, but it's best to do so under veterinary guidance. A supplement can help boost calorie intake or provide specific nutrients lacking in the current diet. Your vet can help determine if it's necessary and won't interfere with their existing feeding program.
Are there any side effects associated with weight building supplements?
When used as directed and under veterinary supervision, side effects are rare. However, introducing any new supplement too quickly can sometimes lead to digestive upset. Always follow the recommended dosage and transition gradually.
What is the difference between a weight builder and a vitamin/mineral supplement?
Weight builders are specifically designed to increase calorie intake and promote muscle mass development, often containing fats, proteins, and energy-dense ingredients. General vitamin/mineral supplements focus on ensuring adequate micronutrient levels for overall health, which may not directly lead to significant weight gain.
How should I store these supplements?
Most horse supplements should be stored in a cool, dry place away from direct sunlight. Always refer to the product packaging for specific storage instructions. Proper storage helps maintain the supplement's potency and shelf life.
Can I combine different weight building supplements?
It is generally not recommended to combine multiple weight building supplements without consulting your veterinarian. Doing so could lead to an oversupply of certain nutrients or an imbalance in your horse's diet, potentially causing adverse effects.

How we compare Vitamins & Supplements

1 Specifications: we compare the key features and specifications listed by the manufacturer and on Amazon.
2 Customer ratings: we take into account the average Amazon rating and the number of reviews.
3 Price: we check the current price and highlight notable deals.
4 Updates: comparisons are refreshed regularly as prices and availability change.

Our comparisons are reviewed and updated regularly to reflect the latest products and prices.

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