I would say yes. But you need to define your "work". If you are looking to lose 15 pounds in a week I would say no. How informed and ready are you? Have you shopped and prepared for the weeks food? Are you willing to exercise? Drink the extra water? If you are significantly over weight (needing a lose of more than 30 pounds) and you follow this plan and you exercise you should see about 5 pounds (if you have no health issues, there is soy in this product and soy does affect thyroid medication).
I prepared for the plan. Started cutting back on my portions before starting the kit. Read a lot of the reviews. Started taking my thyroid medication at night. You get the picture. Preparation. Most of the negative reviews, in my opinion are missing a step and or not every product is for everyone. You need to eat your snacks - that is very important. Skipping = sabotage. The reality is, it is better to be a few calories over with apples and bananas than to skip them.