Q.Is it true that your skin benefits from changing the facial products used for cleansing, toning and moisturising – and if so which product(s) is it most beneficial to change and how often? 
A.W-e-l-l…  There’s no proof of this, that’s for sure.  BUT (as you might expect), we have a few thoughts.  First:  occasionally changing the product you use diminishes the ‘boredom factor’ that sets in with most skincare over time – and so you may actually use the product more diligently, if you switch to a new one, as it engages your senses all over again:  a new smell, a new texture…  But skin doesn’t ‘get used’ to something.  That’s a myth.  More likely, there are subtle changes in skin over time, which mean that a product is no longer so effective because it’s your own skin that’s changed.  Almost every woman we know develops drier and/or more sensitive skin, as she ages – so what worked at 25 just won’t be as good at 35, let alone 45.  Our friend John Gustafson, meanwhile, counsels that each time you reach the end of a jar or a tube, you should basically ask yourself:  is this product doing as much for my skin as it did when I started the jar/tube, or should I be looking to change it?  And of course, if you’re looking to switch, we do suggest you start with our books, because our Tried & Testeds have identified which, of thousands and thousands of products, are the most effective.  (Us?  We’re not afraid to say that we’ve in some cases stuck with the same products for aeons, and are just as happy with them now as on Day One.)