If you mean Isagenix, I have heard of it and even tried a few things from them... I didn't find the product particularly good or bad... though some of them do have a funky taste. I didn't really care for them. I got a few of the products because someone I knew was selling them.
What you definitely should know is that Isagenix is one of those multilevel marketing programs. Which means that (depending on who sells it to you) there is usually a lot of pressure to buy it... then pressure to become a "distributor"... then pressure to sign people up on your "team" and get them to sell it.
I had some health issues and my doctor wanted me to stop using it and do something else for a few months. The person who sold it to me wanted to know if they could call me doctor and talk with her. (I declined!) Now, I'm not saying that everyone who's involved in the program is this aggressive, but my general experience with these type of MLM programs is pretty similar to this. Anytime you have someone who makes income based on whether you use the product, you'll usually get some sort of pressure.
Personally, I think you can find comparable quality products at much cheaper prices without being locked in to programs, going through the hassle, having people call you and call you when you don't want to use it anymore, etc.
There are lots of reviews of the program if you Google "Isagenix Reviews."