The only things that are "required" are your HNS (High Nutrion Supplement) drinks (aka the protein drinks they sell), a multi-vitamin (can purchase anywhere) and your EFA supplements (Fish Oil, Flaxseed Oil, Krill Oil...you can purchase these anywhere).
Anything else you purchase from the center is optional and up to you. Today's economy makes it easier to tell them no.
I have found some of their products work for me and I purchase them. However, what works for one person may not work for the next. I've learned by trial and error.
Whatever your decide, I wish you the best of luck on your journey.