Normal skin contains a good deal of water, which makes skin look plump, fresh and healthy. Skin that has lost its natural moisture looks dry, wrinkled and cracked and feels extremely uncomfortable.Because it is so important to retain moisture levels, your skin produces constant supplies of natural oil to seal off the skin surface and prevent the evaporation of those precious water supplies. Unfortunately, however, most of us remove that natural oil when we wash. The oil disappears, together with the surface dirt and the dead skin cells. And when the natural oil has gone, the skin is left in a very vulnerable state. Water is almost inevitably lost and the skin becomes dry and cracked.
That's why moisturizers are so important. They enable us to replace those missing natural oils and to help keep the skin moist and fresh looking. Moisturizing creams do their job not by adding moisture to the skin (as their name rather suggests) but by preventing the loss of moisture that is already there.
Moisturizers work in much the same way that waxed paper helps keep bread fresh - not by adding anything but by preserving what is already there.
Most moisturizing creams contain a mixture of oil and water. The thickness and texture of the cream depends on just how much of each substance it contains:
Vanishing creams are at one end of the scale. These contain a relatively large amount of water and a small amount of oil, and they more or less disappear when rubbed on to the skin.
Cold creams are at the other end of the scale. They contain a high proportion of oil, and tend to be much stickier and thicker. If you want to buy the most efficient protective moisturizer available, you should probably choose something like a petroleum jelly that is more or less all oil.
Although the basic constituents of a good moisturizing cream are very simple, most manufacturers do their best to make their cream sound special, complicated and unusual. I really don't know of any reason why you should look for a moisturizing cream made with one particular type of oil, however exotic. Unless it produces an allergy reaction when applied to your skin or smells particularly horrid, one oil will do much the same job as another.
You can buy moisturizing creams with added vitamins, placenta extract, honey, seaweed and heaven knows what else. Again, I don't think these constituents will make any difference at all to the efficiency of the product, although they will undoubtedly make a big difference to its price.
Finally, there are moisturizing creams that contain 'humectants'. Humectants (and that includes substances such as glycerine) absorb moisture from around them. The theory is that the humectant will work by attracting moisture from the atmosphere. It is, therefore, a genuine 'moisturizing' cream in that it is actually bringing moisture in to the skin. That's the theory anyway. In practice, if there is not enough moisture in the atmosphere, the humectant will still have to attract water from somewhere. In the absence of moisture in the atmosphere it will draw its water' supplies from the skin - thereby doing harm rather than good.
My own feeling is that you should buy several very large pots of the cheapest moisturizing cream that you find acceptable, and keep those pots in various places around the house so you can use them often without going into the bathroom or bedroom.
Always apply a moisturizing cream after you have washed (if you put the cream on while your skin is still slightly damp your skin will retain that extra moisture) and keep a jar near to the kitchen sink so that when you've been washing up you can apply some cream. Use a moisturizing cream all over your body after a bath or a shower - don't forget your knees, feet, elbows, arms and thighs.
The added bonus from using a moisturizing cream regularly is that you will obtain some protection from the world around you. Very few of us live far away from factory chimneys these days, and the air we breathe in is often very polluted. You've only got to look at old buildings to see the harm that acid in the atmosphere can do. Just imagine the harm that air is doing to your skin. A moisturizing cream will provide some protection. It will also provide some protection against the sun: sunshine dries and ages the skin but the regular use of a good cream can delay the process.
Finally, if you suffer from dry skin, eczema, pruritis (itching), psoriasis or just about any other long-term skin problem, the regular use of a plain moisturizing cream will help to minimize your symptoms. http://myshabi.blogspot.com/2008/10/how-do-moisturizers-effect-skin.html