Dear Dr. Bailey, What is the difference between dry and dehydrated? A lot of skin care lines carry different products for dry skin and so called dehydrated skin. Can the skin be oily and dehydrated? Can skin be dry and not dehydrated? Or is dehydrated skin only a marketing buzzword? Thanks a lot for giving great answers to great questions on your blog! I really like reading your answers and skin care advice. :) and thanks a lot for this answer too. Judith
Hello Judith, I like this question! Yes in this context it's a marketing term but we can use it as a great jump off point for an interesting discussion about moisturizers and skin hydration.
Skin moisture is actually water, not oil and this is why the topic is both confusing and fun.
There are different ways to trap water in the skin.There are also some conditions that cause the skin to lose more water than is good for it, causing it to become overly dry and irritated. So, the long and fun answer: Moisturizers traditionally work by utilizing an oil, which when applied right after washing/wetting the skin will trap water by sealing over the skin and preventing evaporation.
Skin with adequate trapped water is considered hydrated.
Some of my favorite moisturizing oils are shea butter, jojoba oil, coconut oil, and sesame oil. Mineral oil works really well too, in spite of the fact that it gets a bad rap for being a petroleum product.
Oily skin will hold more moisture because it produces its own moisturizing oil.
It is very efficient and wonderful until the oily shine becomes annoying. Harsh soaps will remove the oil and it takes time to reproduce it so any absorbed water from washing may have evaporated by the time the oil begins to re-coat the skin. That said, people with oily skin usually don't like oil containing moisturizers because they have enough oil and oily shine already.
There are non-oil ingredients in skin care products that can bind water too. These are especially great for oily skin moisturizing, but every skin type benefits from them.
Some of the best oil free moisturizing ingredients to hydrate skin are:
- hyaluronic acid (sodium hyaluronate)
- alpha hydroxy acids.
These ingredients are capable of holding water in the skin without needing oil to do it. They're that brilliant bridge between science and nature that I love so much!
Products with these ingredients would be my choice for hydrating oily skin. Products I rely on for re-hydrating dehydrated skin, and that I have a lot of experience with include:
One of my pharmaceutical-grade hyaluronic acid containing products including Green Tea Antioxidant Skin Therapy and/or Instantly Luminous Multi Action Serum. In fact, these work so well together that I created my popoular Layered Up Besties Kit with them both!
A moisturizing cream with squalane, glycerine such as my Daily Face Cream for Oily to Normal Skin.
An AHA (glycolic acid) such as my Glycolic Acid Anti-Wrinkle Face Cream.
Skin can have sub-optimal water content and be considered relatively dehydrated. This is most likely to happen when your skin is irritated to the point that it's barrier function is compromised and moisture escapes.
Common skin conditions that damage the barrier strength of your skin include:
- Repeated contact with harsh soaps (for sensitive skin this can include products with the sodium laurel sulfate family of ingredients) or harsh chemicals (like rubbing alcohol or household cleaners).
- Rashes such as facial dandruff that can cause a compromised barrier and water loss.
- Having a genetic tendency for eczema, asthma and allergies that means you may also have an inherently vulnerable skin barrier and are one of the classic 'sensitive skin' people.
- Exposure to harsh environments such as windy, cold climates, or simply going between cold outdoor temperatures and heated indoor environments which can irritate the skin and cause water loss.
it's possible to have oily skin that is also dehydrated!
Understanding this and knowing whether your skin is oily and/or dehydrated can help you pick appropriate products, but I wouldn't count on a products marketing spiel to accurately guide you. Look at the product ingredients to see if they contain oils or one or more of the non-oil water binding ingredients. Thanks for sending me a fun question, I've been meaning to cover this information and you gave me the perfect reason to do it now.
Cynthia Bailey MD, Dermatologist
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