Hygiene. Why it's not a good idea to use shampoo to wash your body

It's happened to all of us at least once: forgetting our shampoo or shower gel and replacing it with whatever we have on hand – shower gel to wash our hair – or shampoo to wash our body. After all, what's the difference?

Shampoo and shower gel are both hygiene and cleansing products, composed of water and surfactants. "These products are practically identical," confirms Laurence Coiffard, a doctor of pharmacy, specialist in cosmetology and professor at the University of Nantes.

These surfactants allow the product to foam, to cleanse and to dilute the oils present on the skin or hair in water.

Shampoo, often irritating to the skin

So, are shampoo and body wash (for the body only) interchangeable? "The vast majority of shampoos contain what's called a conditioner, which makes styling easier and reduces static electricity in the hair. This component isn't present in body wash and could be irritating to the skin," explains the specialist. Therefore, using shampoo could, in the medium term, be detrimental to skin health.

This is even more true for shampoos with a specific function, such as anti-dandruff shampoos, which very often contain antifungals. "These products contain very specific ingredients, designed to eliminate dandruff after a 5-minute application time. These products are irritating to the scalp and even more so to the skin," notes Laurence Coiffard.

Moreover, for the health of the scalp, it is not recommended to use an anti-dandruff shampoo at every wash, but to alternate with a normal product or to stop the treatment after a given time.

Shower gel, the enemy of hairstyling

The same goes for shampoos for color-treated hair. "They contain a sunscreen that has no business being on the skin." Especially in winter when skin needs sunlight to synthesize vitamin D. Shampoos for volume, shine, detangling, defined curls… all contain an ingredient that doesn't target the skin and can damage and dry it out after several uses. Especially if the skin is sensitive.

According to our expert, using shower gel instead of shampoo would be less damaging. "Shower gel will have no negative impact on the health of your hair. However, you might find it harder to style. Your hair will be more static, but there's no danger to the hair or scalp, which is just another part of the skin. Besides, you can find body and hair shower gels on the market, but never the other way around!" Your hair might also feel heavier, duller, and lack volume…

What about soap? "Soap is not a good product for either hair or skin. It dries out the skin and scalp and does not clean the hair. It makes the skin's pH more alkaline, which makes it more vulnerable to external attacks," concludes Laurence Coiffard.