Ah, blonde hair. It conjures up the nostalgia of Sun-In, the sexiness of Brigitte Bardot and makes us wish we all could be California girls. Except when brassy tones creep in and ruin the sun-lifted effect. Thankfully, both bottle blondes and those naturally blessed know the secret to keeping a hue cool is the best purple shampoo.
What causes brassiness?
‘Lighter strands often struggle to look shiny and healthy,’ says Steve Shiel, scientific director at L’Oréal. ‘This is because free radicals in the colouring process break down protein so blonde hair becomes porous.’
This porousness means bleached hair soaks up unwanted minerals and metals in your tap water and acquires a yellow tinge over time.
‘It also means that blonde hair absorbs light instead of reflecting it and is more prone to damage,’ adds Shiel.
What is purple shampoo?
Put simply, violet-hued shampoo is the haircare equivalent of a surly bodyguard. It protects against dullness and unwanted warm tones between colour appointments.
The latest hair dyes, like Schwarzkopf Color Expert, come with post-treatment conditioners to really lock in the colour, and using purple shampoo alongside these can really help prolong your shade.
‘Purple shampoo neutralises the yellow in blonde hair, leaving a creamy to ash result,’ explains leading colourist and celebrity favourite, Josh Wood. ‘This is because yellow and purple sit opposite each other on the colour wheel.’
So when you wash with this particular shade of shampoo, it deposits purple pigment into blonde hair, to counteract any yellowy tones that start to shine through.
How to use purple shampoo
This may seem obvious but a violet-based shampoo is not made for your daily lather.
Those who bleach and live in hard water areas (which creates more mineral build-up on strands), should only use it once a week.
Meaning, one bottle will last you until your next colour appointment, if not longer.
But Zoe Irwin, creative director at John Frieda Salons, advises clients to be careful as purple-based products can be drying.
‘I decant half my purple shampoo into half a bottle of Oribe Shampoo For Moisture Control,’ she says.
‘The effect is softer, both in terms of the colour and how my hair feels afterwards. I wouldn’t recommend taking your purple shampoo right down to the ends.The hair there can be up to four years old so will grab onto too much of the purple pigment. If you can’t avoid it, coat the ends in conditioner first to create a hydrating base and to dilute the shampoo. Then apply your purple shampoo in an ‘s’ shape on mid-lengths and work it in with your fingers to deposit the pigment evenly.’
Staining is another issue you’ll want to avoid.
‘If you leave a purple shampoo on for too long, your hair will have a blue-purple tinge to it,’ Irwin cautions.
Session stylist Ali Pirzadeh concurs and recommends using your regular conditioner afterwards. ‘I wouldn’t bother with a purple conditioner as well, as you want to make sure your hair is still being nourished.’
Here are our picks for the best purple shampoo. There’s something for everyone – whether you’re looking for the best shampoo for oily hair or one that will give you more grit for styling. And that’s not all. We’ve also pulled together some natural options, so if you have a sensitive scalp, you’re in luck.