My horse gets weekly hypersensitivity shots, and occasional dex injections during the summer due to severe reaction to fly bites but it's not enough. She still itches so bad she bends panels, moves fencing, tears up fly sheets, fly boots, and fly masks, and has ruined just about everything she can come into contact with to rub up against to itch. I've used just about every OTC product and supplement. This is the first product that actually works! Following an IR shampoo bath, I sprayed generously in affected areas (almost everywhere). It's been one week, and only her fly mask has come off, and nothing broken in her corral!