Magnitude- its fantastic- tried loads and found that to be the best - cost around £15 for 6m supply so its worth a try at least..thinks its by Equine America...
Agree about magnesium calmers - not always great! found NAF Easy Going is excellent.Its a herbal calmer, doesnt contain valerian so you can compete whilst feeding it and isnt too expensive
I found Magic and Oestress for my mare particularly when she's in season and some homeopathic remedy i had found online which works like a dream(cant remember its name)
Ditto the Equine America So Kalms - fantastic. I can always tell when my mare's missed one or two doses in her feed - totally makes a difference with her.