Not sure what your question means. As for weight loss products, it's not so much that none of them do anything, some do some things, it's that they really don't do very much unless they contain things in them you're better off not taking. Most of them contain some form of speed and some contain actual speed; some contain laxatives. Most contain things that cause the body to warm up, which does help burn off a little fat but it's pretty inconsequential. The stuff that really works, again, isn't good for you. Long term weight loss, the kind that stays off, requires permanent changes to the way you eat and the way you move.
Neither do I fully, understand your question.
I agree that there are some weight loss products that are effective - meaning they do work, but they also may have unwanted side effects or they may not work on a long-term basis. Most of them are to be taken only until one has reached the desired weight (or has lost a certain number of pounds). Once you go off the weight loss product, it's very likely the weight will return; often one will gain back even more than was lost.
The best way to lose weight is by figuring out a reasonable diet and exercise program that works for the individual, then work to change one's lifestyle rather than trying for quick fixes like weight loss products.
All of that said, the first things one should do is check with your doctor to make sure there aren't underlying medical issues causing the weight gain/inability to lose. Possible medical problems that cause weight gain/inability to lose weight include hypothyroidism, insulin resistance, type II diabetes, Metabolic Syndrom, certain medications and others.