Integrated Bio Sytems Equine Dynamint Leg & Muscle Rub The formula is "All Natural", with soothing peppermint, calendula, eucalyptus, mineral and tea tree oils. It has proven effective as a leg brace and tightener, skin brace and sweat It works very well at alleviating muscle damage and tendon strain and has excellent swelling reduction properties. It works for people too. 500ml / 16 fl. oz.