Skin moisturizing = hydration?

Not entirely true

Although there is some connection between skin moisturizing and hydrating, they are not exactly the same.

This is a discussion based on the definition. Hydration refers to providing moisture to the skin through external means, such as using water-containing solutions, sprays, etc. Its main purpose is to directly replenish moisture to the skin, thereby temporarily solving the problems of dryness and tightness caused by lack of water. However, simply replenishing moisture cannot provide long-term moisturizing because the water will evaporate due to environmental factors.

Skin moisturizing is another matter. It refers to helping the skin lock in moisture through various means, reducing or preventing its evaporation through the epidermis. The moisturizing function of the skin mainly depends on the health and integrity of the skin barrier. This barrier includes the sebum membrane, the stratum corneum and the intercellular lipids, which together constitute the skin's self-protection barrier and can effectively prevent water loss. Commonly used moisturizing products include lotions, creams, etc., which contain moisturizers (such as glycerin) and/or occlusives (such as vaseline). These ingredients can form a protective film on the skin surface, reduce the evaporation of water, and thus keep the skin hydrated.

In addition, skin moisturizing involves a number of complex processes aimed at enhancing the skin barrier's protective capabilities, which may include natural moisturizing factors in the skin, such as hyaluronic acid and ceramides, which help the skin maintain appropriate moisture levels.

To sum up, hydration is to provide moisture to the skin, while moisturizing is to help the skin lock in moisture. Both have their own characteristics, but the role of moisturizing is more important. If you simply hydrate without moisturizing, the moisture in the skin will evaporate quickly and the ideal effect will not be achieved.

Author: Tang Jiaoqing, MD, attending physician of dermatology

Review | Feng Jun, deputy chief physician of the Dermatology Department of Sinopharm Tongmei General Hospital