10 Best Weight Gain Supplements For Horses 2025 in the United States

The Horse XL supplement by Equinety is designed primarily to support injury repair, joint health, and hoof strength in horses of all ages and breeds. Its key benefit is its high-quality blend of essential amino acids, which are important building blocks for muscle and tissue repair. The supplement is free from fillers, soy, sugar, and artificial additives, making it a clean, natural option that is safe for regular use. One tub provides a 100-day supply with a simple dosing routine.

This product focuses on providing protein through amino acids rather than delivering calories or fats to increase a horse’s weight. It comes in an unflavored powder form that is easy to mix with feed, supporting palatability. While it does not contain added vitamins or minerals targeted at weight gain, its natural and pure ingredients contribute to good digestibility, which supports overall health and nutrient absorption.

Horse XL also claims to aid mental focus and immune health, extending its benefits beyond joint and hoof care. It is a solid choice for enhancing recovery, muscle repair, and joint function with a clean, vet-approved amino acid formulation. For those seeking a supplement specifically aimed at weight gain with higher calories, fats, and comprehensive vitamins and minerals, other products may be more suitable.

The Farnam Weight Builder Horse Weight Supplement is designed to help horses maintain or gain optimal body condition by providing a high-fat, nutritionally balanced formula without added sugar, which reduces the risk of digestive issues. Its standout feature is the 50% fat content, supplying more calories than typical grains, making it effective for adding energy and weight safely. It also includes omega-3 fatty acids from flaxseed meal and stabilized rice bran, supporting healthy skin and a shiny coat, which is a nice bonus beyond just weight gain.

The powder form mixes easily with regular feed and is palatable, increasing the chance your horse will eat it willingly. The supplement is intended for all life stages and larger breeds, with flexible dosing up to two scoops daily depending on the horse's activity and weight goals. The 90-day supply and positive customer ratings indicate good value and satisfaction among users.

This supplement suits horse owners needing an easy, fat-focused calorie boost for weight gain or maintenance without sugar, especially for horses sensitive to grain sugars or prone to digestive upset.

The Purina Amplify Equine High-Fat Horse Supplement is designed for a variety of horses, including those in maintenance, breeding, and performance. One of its standout strengths is its high caloric content which is beneficial for horses that need to gain weight. The presence of added antioxidants, including Vitamin E, helps address the harmful effects of free radicals, potentially improving health.

It also features an optimal fatty acid profile to support the immune system and promote a healthy skin and coat, which is a significant advantage. Additionally, its calorically dense formula with controlled starch means you can feed your horse less while still providing adequate nutrition, making it cost-effective in the long run.

The supplement is a powder form and comes in a 50 lb bag, with a rice flavor which should be palatable for most horses. It is suitable for all life stages, making it versatile for a wide range of horses. However, at 54 pounds, the product is quite heavy and might be cumbersome to handle. Therefore, it is recommended to consult with a veterinarian to ensure it meets your horse's specific dietary needs.