Not true at all. This is not something you take at random times though, it's used before starchy meals. You take it before cheat meals, carbo loads, or small doses before meals on a regular basis. Yes, it can and DOES lower blood sugar, but it does this by increasing insulin sensitivity in muscles (does not effect insulin sensitivity in adipose). People have used it effectively, and unlike insulin it promotes fat loss. Insulin, on the other hand, tends to cause fat gain.
EDIT: It can also be used to go into keto, but I don't know how this protocol works nor if it is safe.