This Is What a Hot Shower Does to Your Skin and Hair

If you haven’t read it on this blog, I’m sure you’ve seen the following guidance somewhere: Avoid taking hot showers, tempting as they may be, because they’re bad for your skin and hair. 

In this post, we’ll dig a little deeper and learn what, exactly, hot water does to skin and hair.

The impact on skin

The research in this realm is, well, thin. Most of the studies on the effects of bathing on skin health focus on the use of cleansers. But it’s widely accepted among board-certified dermatologists that hot water, especially when coupled with soaps that contain fragrances and irritating detergents like sodium lauryl sulfate, may damage the skin barrier, or outermost layer of skin. Here’s why.

The skin barrier is composed of dead skin cells, which are surrounded by a dense matrix of fatty substances like ceramides, cholesterol, and fatty acids. These substances, which are known as lipids, help the skin retain moisture and protect it from environmental allergens and irritants.

There’s a thin layer called the acid mantle that resides on top of the skin barrier. The acid mantle is made of acids found in sweat, amino acids, and sebum – an oily substance released from glands near the hair follicles that retains moisture. This layer protects the skin barrier from harmful bacteria and helps keep it strong.

A scalding shower may remove some sebum, resulting in dry skin. The lipids matrix could also be compromised, which would make the skin barrier more permeable and allow water to more easily escape. 

A study published in 2022 found that when adults submerged their hands in hot and cold water, hot water did more damage. The skin turned red, the skin barrier weakened, and the skin ultimately lost more water than it did as a result of the cold-water submersion. The hot water also increased the skin’s pH level, which has been shown to disrupt the skin barrier and increase water loss.

Hot water can also leave skin looking dull and feeling tight.

The impact on hair

While the glands that release sebum are found almost everywhere on our skin, there’s a particularly high amount of them on the face and scalp. When a gland on the scalp releases sebum, the substance coats the outermost layer of hair strands, keeping the hair moisturized and protected.

Similar to its effect on skin, hot water may strip this coating from hair, leaving it feeling dry and brittle. But the research exploring this is very limited.

Your new shower routine

If you have dry skin or hair, or a condition like eczema that hot water may worsen, you can probably get away with taking a hot shower once a week. You may be able to enjoy them even more often if you have oily skin or hair.

But it’s a good idea to take lukewarm showers most of the time, and to limit them to 10 minutes.

You should also use a gentle, fragrance-free soap and shampoo, if you aren’t already. Some soaps and shampoos contain irritating ingredients that may weaken the skin barrier.

And instead of washing your hair every day, consider doing it only when necessary, like after exercising or using a lot of products, or when your hair feels very oily.

Finally, moisturizing soon after exiting the shower will help lock in moisture. Pat yourself dry with a towel, leaving your skin a little damp. Then apply a ceramide-, glycerin-, or petroleum jelly-fortified ointment or cream – which do a better job of moisturizing than lotions, especially during the winter months.