Global herbs flyfree many people use sprays and nasty chemicals to help combat the flies during the summer months which can be quite harsh on the horses skin global herbs flyfree provides a traditional unique and powerful way to help horses tolerate flies the plant extracts in flyfree are digested and pass through the skin to create a protective shield around your horse that lasts all day not only does flyfree help your horse cope with flies but it also helps with general skin condition