Hair dye, dandruff and scalp
Dyeing hair has become increasingly popular. But it might be doing damage to your hair and scalp that you can’t see. Read our guide to find out more.
Hair dye and dandruff – what’s the link?
Is there a link between hair dye and dandruff?
The effect on your hair of salon and box hair dyes is not always limited to a lovely colour.
These chemical dyes could cause problems that leave your hair weak, dry and brittle. In extreme cases, hair dyes can cause hair loss due to breakage.
Their effect on your scalp can be equally frustrating. Hair dye can cause the scalp to itch and flake – but is this dandruff? First of all, it helps to understand what dandruff actually is. While there are a lot of conditions that cause dandruff-like symptoms, what we typically called dandruff is caused by one thing: Malassezia globosa.
Malassezia globosa is a microbe that lives on the scalp. It survives off the natural oils present on your scalp, and for many of us, it is pretty harmless.
Unfortunately, sometimes people are sensitive to it - and in those cases the body responds by showing the signs of dandruff.
The link between hair dye and dandruff
The simple truth is that hair dyes themselves don’t create dandruff. However, if you’re already prone to get dandruff, hair dye could contribute to a flare-up.
So, what’s actually happening on the scalp?
First, the chemicals in hair dyes can remove the protective lipids/oils from your scalp, leaving it exposed and vulnerable to damage from irritants like Malassezia globosa.
This could make it more likely that you will develop dandruff.
Second, the strong chemicals in hair dyes can be irritating by themselves…especially if your scalp is already weakened due to dandruff.
You may experience symptoms of contact dermatitis:
Scalp itching due to skin irritation
Finally, certain chemicals in hair colour, like Paraphenylenediamine (PPDA), are known sensitizers, which means that people could develop an allergic reaction to after repeated exposure. This can also lead to dandruff-like symptoms. If you have an allergy to PPDA, you should avoid all oxidation-type hair dyes (these kits usually have 2 bottles that you mix together).
Hair dye: is it damaging your hair and scalp?
Hair dyes contain a cocktail of strong chemicals, so it’s no surprise that frequent use of them could damage hair.
Dyes can include chemicals like:
Hydrogen peroxide, and
Sensitizers like Paraphenylenediamine (PPDA)
Each of these chemicals may cause problems, from drying hair out, to leaving it brittle and prone to breakage.
They actually do this working as a team. Ammonia allows the dye to penetrate the shaft of your hair by swelling it and lifting hair cuticles, the protective plates that cover hair. Hydrogen peroxide destroys your hair’s natural colour, while also drying it out.
Hydrogen peroxide destroys your hair’s natural colour, while also drying it out.
The chemicals also strip away hair’s natural protective lipid layer, leaving it exposed to future damage and feeling rougher.
Dyes used as colour additives bring their own challenges. Sensitizers such as PPDA in particular are known as a common allergens.
Combined, these ingredients can be very damaging indeed, even causing hair loss due to breakage over time.
How dye affects your scalp
Unfortunately, the damage doesn’t stop at your hair. Frequent scalp exposure to the chemicals used in hair dyes can bring its own problems.
These chemicals can remove the protective lipids/oils from your scalp, leaving it exposed and vulnerable to damage from the environment, styling products and other irritants. Luckily, there are steps you can take to minimize the damage.
Dyeing hair safely
Any time you dye your hair you’re exposing yourself to potential problems. But with some care you can easily manage the risk.
Always follow manufacturer’s usage instructions
Start with a healthy scalp: don’t use hair colour until scalp issues like dandruff or psoriasis are resolved
Refrain from washing your hair a day or two before colouring – the natural oils help protect your scalp while colouring
Before you start on your hair, put a small amount of dye on your skin to rule out the possibility of an allergic reaction
Always wear gloves when dyeing your own hair
Don’t leave hair dye in longer than the instructions recommend
Don’t mix dyes from different brands together.
Use the conditioners that come with colorants, and regularly use conditioner whenever you shampoo to help protect your hair and scalp.
Before and after colouring, a nourishing shampoo will help strengthen weakened hair, while moisturizing and helping protect the scalp from irritation. If your scalp is particularly sensitive, a gentle shampoo will help take the sting out of your day-to-day hair routine.