Gertrude Stein once said, “A difference, to be a difference, must make a difference.” That phrase helps keep my common sense focused when a new procedure or drug is introduced. Every scientist knows that you can bend science just a bit and design a study that will show exactly what you want. That's one of the reasons there are often conflicting scientific publications. My goodness, Darrell Huff even wrote a book called How to Lie with Statistics. So when I read about how silicone gel smeared on scars can help make them go away (I've never seen this work) or how the herb arnica can decrease bruising after surgery (ditto to this one), and then I read another that says they don’t, I remember Gertrude Stein’s phrase.
So how do you decide whether something really works? Design a paired study. Have 2 identical scars, like those created with breast reductions. When you use these things on only one of them, if they really worked, only one side would be improved. But no one has ever shown a this kind of a difference with these creams.
So, the bottom line is not what scientists can show with complex techniques and statistics, but what you see when you look in the mirror.