How Does Moisturizer Work?

1. How Skin Loses Moisture

    

   • Skin glands naturally secrete oils. When you cleanse your face, though, you wash away makeup, dirt and other debris as well as those natural oils. Also, over time, your glands secrete less oil, which means drier skin that is less supple and elastic, eventually leading to wrinkles. While aging is inevitable, using a good topical moisturizer can slow this process.
     

   Oil- or Water-Based Mositurizers

    

   • Regular moisturizers that are oil- or water-based help retain water content on the skin's surface by locking in moisture. By keeping the skin hydrated with humectants or emollients, your skin will appear smoother and softer.
     

   AHAs (Alpha-Hydroxy Acids) Mosituizers

    

   • Moisturizers that contain alpha-hydroxy acids, which are mostly derived from fruit acids, do more than add surface hydration. They help slough off dead cells that can accumulate on the skin and dull its appearance. This leads to clearer pores and the emergence of a new, fresher layer of skin, as well as softening any fine lines. (Note, though, that these can irritate sensitive skin, and it's always best to do a patch test before applying to face overall.) It's best to use a moisturizer with AHAs at night and use ample sunscreen during the day, as these acids make your skin more vulnerable to sun exposure.

   Retinoid Moisturizers

   • Retinoid moisturizers contain tretinoin, a vitamin A-derived acid which, much like AHAs, also slough off dead cells; these also have a skin-lightening effect, which make it perfect for hyper-pigmentation and sun spots. These should also be used at night.

By: ehow.com