The Basics of Facial Moisturizers (ZT)
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The basic function of a facial moisturizer - which most products perform very well - is to soothe and keep water in the skin. However, experts say most other advertised claims, like the ability to eliminate wrinkles or penetrate several layers of skin, are exaggerated by manufacturers. One popular misconception involves the relationship between dry skin and wrinkles. Scientists say dry skin and wrinkles are not associated; the only link is that dry skin can look more wrinkled. A moisturizer will smooth skin to make wrinkles less apparent, but only temporarily; unfortunately, moisturizing your skin will not have any long-term effect on wrinkles.

Important Features

Experts say a good moisturizer should contain the following ingredients:

Emollients, in the form of plant oils, mineral oils, shea butter, cocoa butter, petrolatum, cholesterol, silicones or animal oils (including emu, mink and lanolin). These lubricating ingredients soften and smooth skin while helping it to retain moisture. Experts say Jojoba, squalene and lanolin are the best emollients because they bear the greatest similarity to sebum (the skin's natural moisturizing agent), are the least comedogenic (pore-clogging), and are most compatible with the skin's biochemistry. Thickening agents like triglycerides, palmitates, myristates and stearates are waxier, but necessary for the fundamental base and texture of the moisturizer.
Water-binding agents are ingredients that keep water in the skin. Humectants (including sorbitol, glycols, glycerins and sodium PCA), which attract water to skin, are important for skin damaged by sun and dehydration, but they won't help your skin retain water.
Soothing agents and anti-irritants, such as bisabolol, allantoin, burdock root, aloe, licorice root, glycyrrhetinic acid, green tea and chamomile extract, are added to many moisturizers to help skin handle ingredients that may cause irritation.
Vitamins and antioxidants, including vitamins A, C and E, get mixed reviews from experts. Some say these ingredients seem to have the ability to aid cell turnover, healing and dehydration, while others insist there's little evidence of their effectiveness when applied topically, especially in the quantity found in most moisturizers.
Alpha hydroxy acids (AHAs) and beta hydroxy acids(BHAs) have been shown to clear pores and remove dead skin, resulting in smoother, moister skin. The best AHA products include glycolic acid and lactic acid, while others use fruit or citrus acid, sugarcane, or even sour milk. The best BHA ingredient is salicylic acid. Experts warn, however, that high levels of AHAs may feel tingly on certain skin types. Also, AHA increases sun sensitivity, so sun protection is an absolute necessity if you're using an AHA product.
Experts also say the following about purchasing and using facial moisturizers:

The number-one cause of skin aging and damage is sun exposure. Therefore, experts recommend your daytime moisturizer have no less than an SPF 15, otherwise sunscreen should be worn any time you are outside, regardless of how long you will be out. It's sunscreen and other sun-sensitive ingredients (like AHA) that create the difference between moisturizers labeled as day or night moisturizers.
Because of the special needs of facial skin, facial moisturizers tend to be thinner and more concentrated, so most experts say you shouldn't use other types of moisturizers on your face. They're mixed, however, about whether you need a separate moisturizer for areas around the eyes, although it's generally agreed that this area is more sensitive.
While some experts say people with oily skin don't need moisturizers, all agree that an oil-free moisturizer is best for those who tend to break out with acne, and that people with sensitive skin should choose a moisturizer without perfumes, petrolatum, lanolin or other comedogenic (pore-clogging) ingredients.
You should always check a product's ingredients; when in doubt, test it on a patch of skin first to make sure it doesn't cause any problematic reactions. Also, be aware that just because a product has a certain ingredient, that doesn't necessarily mean it has enough of it to make a difference.
Experts recommend applying moisturizer just after showering, when your skin is plump with water. You should always apply moisturizer while your skin is still slightly damp.