How does Water damage your Hair? and should I hydrate my hair

Although the hair is hygroscopic, which means that it does absorb water, the outermost layer or the surface of our hair is hydrophobic which means that it hates water and is designed to repel water.

The interior fibres of the hair contain amino acids which attract water, but the outermost surface is a layer of fatty material (which repels water). This water repellent surface is of importance because it facilitates the drying of the hair and it reduces friction between hair fibers so that the hair doesn’t have a dried-out feeling and it’s easy to comb. This is also why oils are beneficial to hair because they also contribute to this hydrophobic layer and make the hair more combeable.

Despite this hydrophobic layer, water vapor from the air is still being absorbed by the inner layers but this is not a problem.

The main problem is that liquid water makes the hair swell. At ambient relative humidity, this doesn’t happen much, but swelling of the hair does happen significantly in liquid water

Notice well the difference between water vapor from the air and liquid water during showering).

When soaked in liquid water (like during showering), the inner cuticles swell but the outer cuticles remain rigid and do not swell. This leads to cuticle lifting off.

Next to this, all types of hair are more vulnerable and break more easily when they are wet, and yes, of course, you need water to shampoo and condition your hair, the use of water for that and water in products is unavoidable. But besides using water for these hair practices, water is not beneficial for your hair. It’s mainly damaging. Make sure to be gentle with your hair when it’s wet.

Those hydrating products contain conditioning agents (silicones, fatty acids, polyquaterniums) which give your hair what we think is a hydrated feel but this is rather a conditioned feel. These ingredients form a coating around the hair fibre or reduce friction.

So definitely use such products but don’t over-wet your hair with just only water i.e. don’t hydrate your hair all the time.