Hair Health

Yes, your hair does need sun protection – here’s what to know

28 JUNE '24

When it comes to protecting our skin from the damaging effects of the sun’s rays most of us are pretty clued up. We know that if we don’t apply sunscreen religiously that our skin can burn (increasing the risk of developing skin cancer) and age at an accelerated rate. But did you know that the sun’s harmful UV rays can also damage your hair? Luckily, sun-related hair damage is becoming more widely discussed, and there are things you can (and should) do to mitigate the effects of UV when it comes to both your scalp and your lengths.

WRITTEN BY SHANNON LAWLOR

What are UV rays?

The sun’s light contains two particular forms of ultraviolet rays that are worth acquainting yourself with if you want to start taking hair-related suncare seriously – UVA and UVB rays. UVA rays can penetrate cloud-cover, glass and other transparent materials and, when it comes to skincare, are the rays that are most associated with signs of accelerated skin ageing. UVB rays, on the other hand, do not penetrate through clouds or glass – these are the rays that are most associated with skin burning and blistering. Why is this relevant to hair, I hear you ask? Well, for starters, it’s important to remember that scalp care is skincare – any exposed areas of the scalp need protecting just like the rest of your body. Beyond that, these two forms of UV radiation can (and do) damage the hair shaft.

What is the general structure of hair?

In order to understand how UV radiation damages hair, you’ll need some basic understanding of the hair’s inner structure. (Bear with us, it’s not a boring science lesson.) A single strand of hair consists of the hair cuticle (the outermost protective layer), the hair cortex (the bulk of the hair shaft) and the medulla (the very small, central point of the shaft). The medulla is so fine and fragile that not all human hair has one – in fact, scientists aren’t even sure of its exact function. So, when it comes to UV damage on hair, we’re most concerned with its effects on the cuticle and the cortex.

The hair cuticle is the thin layer that protects the cortex. It is made up of overlapping scales – when these scales are smoothly overlapping, the hair appears healthy and shiny. When the cuticle is compromised, these scales raise – allowing for the cortex of the hair to become damaged and lose moisture more easily. The cortex is where most of the hair’s structure lies and is also the place where the hair’s pigment is made. Made up of proteins (mostly keratin filaments), the cortex determines the strength, pattern and colour of your hair. The health of the cortex relies on the health of the cuticle that protects it.

What does UVA do to hair?

Research has shown, that UVA rays are mainly responsible for colour changes with hair, particularly when it comes to lighter hair colours. Melanin is what gives our hair pigment – the more melanin our hair has (the darker it is), the more protected the inner cortex is from UV damage. Hair with less melanin (lighter hair) is more at risk to structural damage. UVA radiation penetrates into the cortex and can impact the levels of melanin in hair and cause lightening. Not only can this result in a physical change, but it can also leave the hair more susceptible to protein damage.

What does UVB do to hair?

UVB rays are the real damage causers when it comes to hair. Studies show that UVB rays are mainly responsible for protein damage and loss. Protein (keratin) is the main building block of the hair shaft, making up the majority of its structure – these are the proteins that the cuticle exists to protect. If those proteins become damaged or start to diminish, you can expect a weaker hair fibre. What does that look like? Breakage, splitting, dryness and frizzing.

How can you protect your hair and scalp from UV damage?

#1 Sunscreen

When it comes to your scalp, it is imperative that you are treating it like the rest of your skin – applying sunscreen to all exposed areas and reapplying throughout the day. And don’t worry, that’s not to say you have to slather made-for-skin creams and lotions into your hair. In fact, there are a number of specialised sunscreens on the market that have been formulated to protect both hair and scalp.

Aveda Sun Care Protection Hair Mist

As a lightweight mist, Aveda Sun Care Protection Hair Mist, packs a punch. It provides up to 16 hours of protection against UV-related dryness, damage and colour fading – and it smells beautiful while it’s at it.

Coola Daily Protect Scalp Mist SPF30

This broad-spectrum sunscreen Coola Daily Protect Scalp Mist SPF30 can be used on both hair and scalp, but the targeted nozzle makes it particularly great for scalp protection. Just spray onto your parting and hairline and distribute with a brush or comb.

Supergoop! (Re)setting 100% Mineral Powder

If your roots are prone to greasiness,Supergoop! (Re)setting 100% Mineral Powder SPF30 is for you. Although it is formulated for facial application, the translucent nature of this SPF powder means it can also be brushed onto the scalp for those who have lighter hair. (Super-dark brunettes, it may turn your roots a little ashy, so beware.)

Clarins Sun Care Oil Mist SPF30

If you’re prone to dry skin and dry hair, Clarins Sun Care Oil Mist SPF30 could be for you. You can mist it onto your body and hair for all-round sun protection. Be warned though, it does have a slightly greasy residue, so won’t be one for fine hair types that aren’t planning on an up-do.

#2 Scarves and hats

It goes without saying that the best way to protect your hair and scalp from sun damage is to cover it up. While hats are no doubt the easiest way to protect your scalp and roots from the sun, scarves and wraps are also a great way of protecting the lengths. However, it’s important to remember that UVA rays can penetrate through some translucent fabrics, so keep this in mind. Silk scarves and wraps are the best way to keep the sun off your head, protect your scalp from burning and prevent UV damage to strands – all while minimising breakage-causing friction.

#3 Protective styles

The hairstyle in which you choose can play a part in the level of damage you can expect to see on both strands and scalp. For example, a parting-free ponytail is a good way to protect your scalp, while a bun or braid is also a good way to limit the amount of hair exposed to the sun. Remember, if you’re wearing box braids or cornrows, it’s really important to protect your scalp.