Celebrities used to get away with claiming the secret to their red-carpet-ready skin was simply drinking a lot of water. Now we know there’s way more happening behind the scenes that helps A-listers have flawless skin, but it’s also true that drinking water ― and drinking enough of it ― is necessary to stay healthy.
But how much water is enough? And can the right amount do anything to visibly improve the appearance of your skin?
Hydration can do more for your overall health than for your skin health.
Hydrated skin appears smoother and more supple, but it’s also important for more than just looking nice.
“When skin isn’t properly hydrated over longer periods of time, it can also accelerate the aging process,” said Whitney Bowe, a board-certified dermatologist based in New York. “When our skin is chronically dry, it leads to subclinical inflammation, which means that microscopic signals are shared throughout the skin’s layers, causing your skin to age more rapidly and to become more susceptible to allergens and irritants in your environment.”
This can also lead to a compromised skin barrier, the outermost layer of skin that acts like an armor of sorts for our body. When the barrier is compromised, water evaporates off the skin more easily, which dehydrates it.
So what does drinking water have to do with our skin? Bowe said that staying hydrated is an “inside out, outside in” job, meaning that what we ingest and what we apply to the skin are both critical for skin health and hydration.
A few studies have taken a closer look at exactly what drinking water does for the skin, but they’ve been underwhelming ― both in their methods and their results. For example, one small study showed that increased water intake did make a small difference in superficial and deep skin hydration. However, it was most noticeable in people who started with less daily water consumption in the first place. “This study suggests that most people probably would benefit from drinking more water in terms of their skin health,” Bowe said.
“Dehydrated skin is mostly superficial and is not affected by internal water content. Not to say drinking water is not important, but keeping skin hydrated relies more on skin care.”
– Dr. Jenny Liu, dermatologist
Other research shows similar benefits, but again, we’re talking about a smaller analysis that hasn’t been through peer review. “Clinical signs of dryness and roughness were improved, and even skin elasticity increased slightly with added water consumption,” Bowe said. “However, drinking more water didn’t seem to improve something called transepidermal water loss, which is an important measure of skin barrier function.”
While the body’s hydration level may have some effect on the skin, it may not be enough to make any noticeable difference outside of a carefully measured lab. A line from that last study might sum it up best: “Although we wish we could demolish all of the urban myths found on the Internet regarding the benefits of supplemental water ingestion, we concede there is also no clear evidence of lack of benefit.”
That’s not to say that water isn’t important to your skin, and even more so to your overall health. But it shouldn’t be your first resort when it comes to hydrated skin.
“Indirectly, water is what constitutes the majority of our body and [is] important for the body to function properly, but unless we are severely dehydrated, the water that is drunk regularly doesn’t have significant impact on the skin,” said Dr. Jenny Liu, a board-certified dermatologist and an assistant professor of dermatology at the University of Minnesota Medical School. “Most of hydration is from water content that already exists in the deeper layers of skin.”
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Basically, unless you’re severely dehydrated ― in which case you’d probably be at the hospital receiving fluids ― you probably won’t notice a big difference in your skin with increased water intake. “Dehydrated skin is mostly superficial and is not affected by internal water content,” Liu said. “Not to say drinking water is not important, but keeping skin hydrated relies more on skin care.”
How much water should we be drinking, then?
While the amount of water you drink won’t have a major effect on your skin, drinking a healthy amount of water every day ― especially if you currently aren’t consuming enough ― is a smart idea. (Remember that too much water can actually be dangerous, although this is rare; one example of people who need to be careful about it is athletes competing in ultramarathons.)
“There is no solid science behind the recommendation that eight glasses of water is a magic number when it comes to our skin health, but it’s a useful rule of thumb when thinking about overall hydration,” Bowe said. You can find higher recommendations elsewhere: The U.S. National Academies of Sciences, Engineering, and Medicine suggest 11.5 cups for women and 15.5 cups for men (this includes water from food, which accounts for about 20% of our water intake). This number can change based on where you live and how active you are.
How to properly hydrate with good skin care
Drinking enough water is definitely necessary for good health, but if you have dry skin, it won’t be the cure. “Water is very important but if you don’t do proper skin care it doesn’t matter how much water you drink, your skin can still get dehydrated and dry,” Liu said.
“Moisturizers first prevent water loss through skin, and have ingredients that help to attract water from deeper levels to [the] epidermis,” Liu noted. “They don’t provide water per se.” Keep in mind that even oily or combo skin can be dehydrated. “Hydration refers to water content on the top layer of skin and isn’t directly related to the amount of sebum or oil product,” Liu explained.
“I always recommend a combination of skin care products that can help seal and trap that moisture in the skin,” Bowe said. “A well-formulated moisturizer is essential to complement increased water intake throughout the day, and both work synergistically to optimize skin hydration.”
Bowe recommended skin barrier-friendly ingredients like squalane, ceramides, hyaluronic acid, shea butter and glycerin, and even oils at night. “Oil acts as a barrier and sits on the top layer of your skin,” she said, “so you want to use it as the last layer in your routine, allowing all of those skin care products you apply beforehand to penetrate into the deeper layers.” And if your immediate environment is dry, try putting a humidifier in the room while you sleep.
Water is good for the body as a whole, but it’s not the savior for dry skin you might expect it to be. Drink enough water each day, but enough is enough ― when it comes to soothing dry skin, moisturizer is a better bet.