i like to know too. my stone is 2.5cm. i take the malic acid every day, i figured it is like eating apples. when i started i did one bottle of GCG. after that i did the chanca pietro. now i am doing the chinese bitters for several days and then i switch to the GCG. my problem has been that i use everything once a day till i found the chanca p. you have to do 3x a day. in one of the messages someone suggested to do one after another and see if it makes a difference. may be you will get another response about your question. good luck, hanna