We moved our neddy to a new yard last May and she was a night mare (excuse the pun). I went to the feed merchant for Magic but they didn't have any so bought Magnitude instead. We noticed after about 4 days she was a much nicer horse to be around, still a bit stressy around her seasons but on the whole much better. We stopped about mid summer and she carried on be okay. So far so good this year but if needs be she will go back on it. Well worth the money and cheaper than a lot of the other calmers out there.