To those who had good luck with it, how long did it take for you to see a noticable difference? 

Following... my vet is recommending that for my horse in the spring. She said it will take about 4-6 weeks to see any results so make sure to factor that into your timeline if you give your horses the winter off like we personally do up north. 

Slight improvement in 2 weeks and great at 4 weeks.  Second time I think a little over a year later, nothing.  However we went into it knowing I might not get anything the first time around.

Thanks for the responses!!! I had used it in the past but never noticed a difference but those were 2 horses with navicular and I think were to far gone to help...