Hydrating ingredients in skin care products attract water to the outermost layer of the skin, while moisturizing ingredients lubricate the skin to prevent water from escaping.

Hydration and moisture are two distinct skin care needs. Many products marketed as “moisturizers” have both moisturizing and hydrating properties. Additionally, because there is no consensus on the definition of a moisturizer among experts, some classify hydrating ingredients as moisturizers.

People may not know if they need more hydration or moisture in their skin care routine, but this is not always necessary when choosing products. The American Academy of Dermatology Association (AADA) recommends that people pick products formulated for their skin type, such as dry or oily.

Read more to learn about the differences between hydration and moisture, how to tell which ingredients a person’s skin needs most, and more.

A person diving into a pool of water.Share on Pinterest
vernonwiley/Getty Images

A simple way to differentiate these terms is to remember that hydration refers to water while moisture refers to oil.

Skin care products use different ingredients to either hydrate or moisturize the skin. Some ingredients, such as humectants, do both.

Hydration

Humectants are ingredients that increase the skin’s hydration by attracting water from the environment to the skin. They also draw water from deeper layers of the skin, called the dermis, and bring it to the outermost layer of the skin, called the epidermis.

Examples of hydrating ingredients include:

  • honey
  • gelatin
  • urea
  • sorbitol
  • panthenol
  • glycerin
  • hyaluronic acid
  • alpha hydroxy acids

Moisture

In addition to being hydrating ingredients, humectants are also moisturizing. Other types of moisturizers include:

  • Occlusives: These are oils and lipids that form a layer on the skin to prevent water loss. Examples include petrolatum, beeswax, mineral oil, and lanolin.
  • Emollients: These strengthen the skin barrier function and promote an improvement in the skin’s appearance and texture. Examples include fatty acids and fatty alcohols.
  • Protein rejuvenators: These are proteins that replenish essential proteins that may rejuvenate the skin. Examples include collagen, keratin, and elastin.

According to a 2017 study, experts have not reached a consensus on the precise definition of moisturizers. This means that when it comes to distinguishing hydrators from moisturizers, there is some gray area. As a result, people often use the terms emollient and moisturizer interchangeably.

Many products labeled as moisturizers contain hydrating ingredients in addition to moisturizing emollients and occlusives. Each type of ingredient offers different benefits, so many skin care products have a combination of all three.

Their uses are:

  • Humectants: For rough, thick, scaly, or very dry skin
  • Emollients: For rough, dry skin and routine skin care
  • Occlusives: For very dry skin and preventing atopic dermatitis, which is a chronic red, itchy skin condition

Among the three types of ingredients, there is some overlap in the type of skin they benefit. A dermatologist can sort this out and tell people if their skin requires more moisture, hydration, or both. These professionals can also provide suggestions for specific products that address these needs.

A small 2015 study examined how daily water intake from food and drinks affects a person’s skin. Among 49 healthy females, it compared the skin characteristics of people who consumed more water and people who consumed less.

The results indicated that consuming more water made a difference in some skin characteristics but not others.

When people consumed more water, the hydration in the epidermis — the outermost layer of skin — increased. The authors concluded that higher water intake has a positive effect on skin physiology. Despite this finding, they did not note an optimal daily water intake amount.

However, an older study from 2010 recommended 3,000 milliliters of water per day for males and 2,200 ml for females. This equates to 101 ounces for males and 74 oz for females. Since 1 cup contains 8 oz, this means the daily recommendation is for males to drink 12 cups and for females to drink 9 cups.

Individuals may not know if they need more hydration or moisture. Additionally, few people are familiar with the many ingredients on skin care product labels.

The AADA advises choosing skin care products based on an individual’s skin type. This involves looking for products that have specific formulations for the following skin types:

  • oily
  • normal
  • dry
  • combination
  • sensitive

For aging skin, the AADA recommends choosing products that are hypoallergenic. This means they do not trigger an allergic reaction. It also advocates selecting products that are non-comedogenic or non-acnegenic, meaning they do not cause acne.

Aside from using skin care products, a person can take various steps to keep their skin hydrated and healthy. The AADA encourages people to:

  • Apply sunscreen before going outdoors: This prevents sun damage.
  • Check skin regularly for skin cancer: If an individual can catch cancer early, it is highly treatable.
  • Not smoke: Smoking may accelerate the aging process.
  • Not scrub the skin: Harsh scrubs can irritate the skin, causing redness and breakouts.
  • Gently cleanse the face: Wet the face with lukewarm water, then apply a mild cleanser with the fingertips, using gentle circular motions. Rinse off the cleanser and pat the skin dry with a clean cloth.
  • Wash face upon arising, before going to bed, and after perspiring: This helps remove bacteria, grime, and pollutants.
  • Manage stress: Because stress can trigger flare-ups of many skin conditions, engaging in stress-reduction techniques can help.

If a person has dry skin, the AADA recommends they:

  • bathe or shower with warm rather than hot water
  • limit time in the bath or shower to 5 minutes
  • use a gentle, fragrance-free cleanser
  • apply moisturizers immediately after washing
  • use an ointment or cream containing one or more of the following:
    • shea butter
    • glycerin
    • jojoba oil
    • lanolin
    • petrolatum
    • hyaluronic acid

When people are deciding between products that provide hydration or moisture, it may help to become familiar with a few ingredients that fit into both categories.

Examples of hydrators include hyaluronic acid and glycerin, while examples of moisturizers include lanolin and mineral oil. Because remembering the multiple ingredients that fit into each category can pose a challenge, it may be easier for people to choose products formulated for their skin type, such as oily or dry.