I have been trying to lose weight, and i have been using this product for the past month. I use it in combination with other products (L-carnitine, forskolin), but I can say that i have lost weight (15lbs). It does what it says, did help with my appetite, and kept me fuller for longer time. I will definitely purchase again until i reach my goal.
Fucoxanthin is a low risk but possibly no reward product. There just haven't been a ton of studies conducted on it in human populations. In my personal experience, I did notice an appreciable increase in metabolism and therefore fat loss after about 14 weeks of CONSISTENT use of the product. 14 weeks. Not 4 or 6. And I never missed a pill. I recommend people check out the science behind the product at examine.com (I am not affiliated with them, but it's a great resource) rather than going by Dr. Oz or whichever feel good semi-quack doctor recommended it on the TV as an appetite suppressant (it's not; that's not the mechanism behind the chemicals within). Then decide for yourself if you're willing to be patient enough to see results. It could take time.
My experience after one month has been less than exciting. My weight has been stable for several years—I eat what I consider a healthy diet. I want to lose just a few pounds. I bought a four month supply and thought a realistic expectation would be a four pound loss—a pound a month. I did not change my diet--I did not lose any weight. If it’s necessary to cut the calories to lose anything, why bother with the Fucoxanthin?