Anyone have experience with Tribulus?

Background: I'm 25 years old and have uncomplicated, well-controlled, adult-onset Type 1 (A1c is somewhere between 5.5 and 6.0, no comorbidities, etc.) I'm 6'7", about 218 lbs, and eat like a horse - primarily because I'm trying to put on some muscle (I also power-lift 3x a week). I have a tiny bit of a gut (I could probably stand to eat fewer carbs and drink less beer), but otherwise am in pretty good shape.

I ran across a nutritional supplement called tribulus, which seems to have both testosterone-increasing and glucose-lowering properties. Anyone have any experience with it? I feel totally comfortable playing around with my insulin dosing if need be, but I'd like a more specific sense of how it affects TDD and general insulin sensitivity before I try it out.