I have used them in the past. A long time ago my instructor would give all the horses L-Tryptophan (sp?) before shows. It's not legal in most beeds now though. I've had to Ace my mare in order to get her in a trailer. She's a great loader now but she used to be a genuine nightmare. Since then I've used Quietex and Cool and Calm (or whatever it's called) and they seem to work okay in lower-stress situations. Didn't do a darn bit of good when my mare was determined to spaz out though. :roll: I'd only use them now if she had to stand in a stall for a long period of time due to an injury or something. Beyond that I don't see much use for them. Training and de-sensitizing seems to work far better IMO.