10 Best Weight Gain Supplements For Horses 2026 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 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.

Pennwoods Body Builder 4000 is designed to help horses gain weight and build muscle, featuring a rich combination of 40% fat and 26% protein. These high energy and nutrient levels make it especially suitable for performance horses, lactating mares, or horses that need to improve body condition and muscle recovery. The supplement’s powder form is easy to feed and lasts about 66 days per 25-pound bag when given at the recommended 6 ounces daily.

One standout benefit is the improvement in hoof quality, which is a plus for overall horse health. The product includes essential vitamins and minerals to support growth and longevity, although it contains soy, which may be a concern for horses with allergies. The taste is enhanced by natural and artificial flavorings, which generally makes it palatable for most horses.

Some might prefer an all-natural formula without artificial flavors, and the presence of palm oil might be a consideration for those seeking more natural fat sources. This supplement offers a balanced mix of calories, protein, and vitamins to support weight gain and muscle development, making it a solid choice for horse owners looking to maintain or improve their horse’s condition, especially during demanding periods.