Selenium Supplements for Horses

View a list of the best selenium supplements for horses in Mad Barn’s equine feed database. Selenium is an essential trace mineral that supports antioxidant function, immune health, thyroid hormone metabolism, muscle function, and reproductive health. Equine selenium supplements may provide selenium in inorganic forms, such as sodium selenite or sodium selenate, or in organic forms, such as selenium yeast. These forms differ in absorption, retention, and how selenium is stored and used in the body. Compare product formats, selenium sources, ingredients, dosages, and cost per serving to find a supplement that fits your horse’s nutritional needs.