Many of us here use Esther-C and this subject comes up frequently thankfully or I wouldn't have known about it myself. I've long had my mildly HD GSD Odin on supplements such as Glucosamine/Chondroitin, but some months ago started him on Esther-C as well after reading a thread here about it. MaggieRose and Tula gave me very helpful information. I started him out with a bit too much at 500 mg and the poor guy had serious diahria. I dropped him to 250 mgs by breaking the tablet in half for a week until he could adjust to it and he was much better. Then I brought him up to 500 mg for two weeks and now he's on 1000 mgs a day. It has made a HUGE difference in his quality of life! Although no cure for HD, it does indeed help them live with it much better than without it. My boy is bouncy again and the stiffness in getting up is long gone. We go skijoring together and he has no ill effects from the exercise. Esther-C is very much worth doing.