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Dehydration, itchy skin and dandruff: is there a link?

Dehydration won’t cause dandruff – but that doesn’t mean they’re not linked. Find out how to keep things from getting worse.

We’ve all heard that you should drink 8 glasses of water a day – anything less and you run the risk of dehydration. What you might not know is that not drinking enough water can affect your scalp health, particularly if you have dandruff.

Water drops on the indigo-blue surface.


When it’s healthy, your scalp keeps the bad substances out (irritants, pollution, germs), and the good stuff in (water, nutrients).

When you don’t drink enough water, the scalp can become dry and damaged, causing flaking, itching, scratching…even broken skin. This weakened skin is less effective as a barrier between you and your environment.

If you’re prone to dandruff, the irritants on your scalp trigger dandruff more easily than normal.


It goes both ways. When you have dandruff, your skin’s moisture barrier is weakened, because it isn’t being produced at a healthy rate.

Clinical studies show dandruff causes the scalp to lose more moisture, and become dry.
The combination of dandruff and dehydration can also have serious consequences for your hair, which needs a healthy foundation to grow properly. Add the itching and scratching that can damage hair, and things quickly go from bad to worse.

It’s important to take appropriate steps, with a two-pronged treatment for your dandruff and dehydration.

You should always make sure that you’re drinking enough water – 8 glasses a day, as mentioned, is the typical recommendation. At the same time, if you have dandruff, a hydrating shampoo will help keep your scalp in the best possible condition while you fight the cause of your dandruff.

This simple combination of solutions is the easiest way to make sure that your hair stays strong and healthy. After all, healthy hair needs a healthy scalp.


The most common reason why skin becomes dehydrated is that it is losing too much water to the air via evaporation. This can happen when the skin isn’t healthy, or when the air is very dry. When your skin becomes dehydrated, you can experience symptoms that are very similar to dandruff:

  • Dry flakes in the hair

  • Itchiness

  • Damaged, cracked skin

In fact, a scalp with dandruff can be especially dry. That’s because the skin is unhealthy – in dandruff, skin cells are produced and shed too rapidly. Research shows that dandruff skin is especially “leaky,” allowing too much water to escape from our skin and leading to dryness. This also means that dandruff and a dry, dehydrated scalp caused by dehydration might need to be treated differently.


Treating dandruff is fairly simple – a good dandruff shampoo used regularly will help keep your scalp protected from dandruff triggers and allow your skin to be healthy and moisturized.

To help things along, you might also want to invest in a shampoo specifically formulated to fight dry scalp. These shampoos are designed to help your skin regain lost moisture, giving it the best chance of returning to normal.


Our scalps are designed to hold in moisture, but the balance can easily be disrupted, leading to an uncomfortably dry scalp. Find out how your scalp’s moisture defences work. 

Your body is about 60% water by weight, and it’s really important to keep essential moisture inside. That’s where our skin comes in –from head to toe, our skin is made up of layers.

The outermost layer of the epidermis is the stratum corneum, and it’s responsible for locking in moisture.

When the stratum corneum is healthy, its cells are arranged like bricks in a wall – stacked and overlapping, to build a good barrier to keep water inside your body, so you stay properly hydrated.

What stops the scalp from retaining moisture?
Any condition that weakens the stratum corneum can lead to scalp dryness. The most common scalp disorder, dandruff, can seriously disrupt the scalp’s moisture defences.

Dandruff is a response to irritation – the body begins to produce new skin cells unusually fast, resulting in a more disorganised and unhealthy cellular structure.

We notice increased cell turnover as flakes on our hair and scalp – but under a microscope you can also see that dandruff damages the outer layer of skin, making it 'leaky' and less effective at retaining moisture.

Washing your hair with the wrong shampoo, using water that’s too hot and even cold, dry weather can all dry out your scalp.

A dry scalp can also be itchy, so it’s often tempting to scratch it. But this could cause even more damage to the stratum corneum and disruption to the moisture barrier. So resist the itch!

Help put an end to dandruff, dryness and itch* and restore your scalp’s natural moisture balance with our Dry Scalp Shampoo.

Our pH-balanced formula is gentle on your hair so it’s suitable for everyday use, leaving your hair beautiful and visibly flake-free. **

More about dry scalp

*dryness and itch due to dandruff
** visible flakes from 2ft, with regular use

Dehydration and dandruff