Hello and welcome. I found a few problems with this supplement
1) There are a number of different types of gou teng. I never did figure out which one I should get, so I took a shot and ordered Tian Ma Gou Teng Yin.
2) I ordered two bottles from China but have never opened them. I heard some bad things about the quality of supplements from China and figured I already had PD, why would I add to my woes with a contaminated supplement. No proof that it was contaminated, but better safe than sorry.
3) I asked 2 neurologists, one a specialist in movement disorders, if they had knew anything about the efficacy of gou teng in the treatment of PD. Their response was "Never heard of the stuff."
You might like to read my blog www.wpgchap.blogspot.ca
(or maybe .com - I never remember). It is my journal that I started shortly after I was diagnosed 2 years ago. There is an entry on gou teng if I remember correctly.
I think, as most in this forum do, that the best treatment for PD, along with drugs of course, is lots of exercise and an avoidance of stress.