Recommended amount is 10 grams per day, or at the advice of your veterinarian.
Lysine is an essential amino acid, in that the horse cannot manufacture it from other things. Many hays in the US do not have sufficient lysine, according to the recommendations of the National Research Council, as published in their Nutrient Requirements of Horses.
Supplementation is an easy method to increase the horse's lysine intake per day.
Approximately 10 grams per US tablespoon.
Disclaimer: This product is not intended to diagnose, treat, cure, nor prevent any disease. If your horse experiences any adverse effects from using this supplement, discontinue use and contact your veterinarian. For use in animals only.