Knowing What Soap Goes on Your Skin Is Important

Traditional cleansers may do more harm than good

Depending on the types of cleaners you use, washing your face can often cause more harm than good. Much of the problem comes from how we were taught to wash and the feelings we come associate with cleanliness.

The woman is washing her face.
Michael H / Getty Images

In the past, we were often told that good skincare meant having tight skin after a proper wash. By achieving this, we knew for sure that we had stripped off all of the nasty dirt and oils that could block our pores. We then would then follow up by using a good astringent to ensure that no trace of oil or dead skin was left.

This routine on paper sound pretty good until, of course, the day the obvious happens: we start to realize our skin is not only tight but dry, itchy, and inflamed. Now is the time to start recalibrating our thinking and to take a good, hard look at how soaps actually affect our skin.

How Soap Works

Soaps and facial cleansers are designed to remove dirt, sweat sebum, and oils from the skin. They do so with the use of surfactants, chemical agents that surround dirt and oil, dissolving them and making it easier for water to wash them away. They also aid in the skin’s natural exfoliating process by removing dead cells from the epidermis (the outermost layer of skin).

Surfactants have many different functions: they act as detergents, wetting agents, foaming agents, conditioning agents, emulsifiers, and solubilizers. In addition to soaps and facial cleansers, surfactants can also be found in lotions, perfume, shampoo, and a multitude of other hair and body products.

While the surfactants found in soap are meant to leave the skin feeling fresh and clean, it’s not always the case.

Some surfactants have an adverse effect on the outermost layer of the epidermis (called the stratum corneum), causing not only dryness, redness, and irritation but undermining the skin’s natural barrier function.

By doing so, toxins, bacteria, and other unhealthy substances are able to penetrate deeper into the skin where they can do long-term harm.

How Soap Affects the Biology of Skin

The stratum corneum is made up of layers of dead keratinocytes, or protein cells, that are constantly being shed. Once a single layer of keratinocytes reaches the outermost layer, they become corneocytes. When this happens, the cell loses its nucleus and cytoplasm and becomes hard and dry. Surfactants bind to these proteins and over-hydrate them, causing them to swell.

The swelling allows the cleanser ingredients to more easily penetrate into the deeper layers of the skin, where they can interact with nerve endings and the immune system itself, leading to itching and irritation. Moreover, as the water evaporates from the skin, the corneocytes become even drier than ever as the surfactants effectively strip the skin of its natural moisturizing factor (NMF).

The stratum corneum also contains lipids that help skin retain moisture. While the exact effect of cleansers on these fat cells is still not fully understood, it is believed that surfactants are able to get in between and disrupt the lipid bilayers. These are the fat cells that surround and provide a protective barrier for all cells.

When this happens, the cells can become more permeable and vulnerable to damage. Surfactants can also damage the lipid structures themselves, causing a reduction in the fats within the external skin layers

Surfactants are broadly divided into two categories: soap-based surfactants and synthetic, detergent-based surfactants (also known as syndets).

Soap-based cleansers have a pH level of around 10, making them more alkaline than syndets (which have a pH of 7 or lower). High pH levels cause irritation by compromising the skin's natural pH of 5.5.

Cleansing Tips

Choosing the right cleanser for your face shouldn’t be a chore, but it sometimes is. As a rule of thumb, it is usually best to ditch the traditional bar soap, particularly if you have dry or sensitive skin.

Liquid facial cleansers and body washes are usually better choices since they tend to have a lower pH and often include moisturizers, called emollients, that can counteract any dryness traditional soaps can cause.

Emollient moisturizers contain either occlusives or humectants. Occlusives are oils that reduce water loss and help keep the stratum corneum moist. Humectants increase the amount of water the stratum corneum can hold. One is not better than the other; it's all a matter of personal choice.

When washing, avoid hot water and try not to soak the skin for too long a period of time. This only increases dryness by stripping more of the skin's natural moisturizing factor.

When finished, always pat your skin dry as opposed to rubbing it vigorously. In the end, the more gently you treat your skin, the more you help it retain its natural softness, resiliency, and moisture.

To help retain skin softness and moisture, add a light layer of moisturizing cream or lotion, especially after a hot bath or shower. There are even those with sun protection factor (SPF) if you plan to go outdoors.

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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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