Cosmetics companies want you to believe that they have the answer to fine lines, wrinkles, sagging skin and stretch marks. Just put this cream on and the appearance of fine lines and wrinkles will be visibly reduced! Technically- that statement is true. If you moisturize your skin, the fine lines and wrinkles will plump up and they will appear to fill in. This does not mean that you will have any real reduction in wrinkles. It just means that if you use this product (and continue to use it) your wrinkles will look better.
Sadly, most consumers expect that a wrinkle cream will make their wrinkles fade away and disappear. Unfortunately there is no lotion, serum, cream, or oil that can reverse the effects of age and gravity on our bodies. The only thing that can do this is plastic surgery. A cream that says it will "help" tighten and tone your sagging skin may have and ingredient in it that tingles or feels tight so that you know its "working". Wrinkle serums frequently contain plumpers like pepper extracts which are really just irritant to your skin. They cause inflammation and swelling, or plumping. There is nothing that can penetrate the skin layers all the way down to the snapped elastin fibers and make them grow back together to heal your stretch marks. (I sure wish there were!!) The best any cream can do for you is have skin lightening ingredients to help the redness fade away- which time will eventually do by itself.
Women spend a lot of money on products that claim to be "Better than Botox!" but you should really just save that money for the real thing.