Purple Shampoo Could Be Messing Up Your Blonde Hair – Here's How

As a natural brunette with blonde balayage — who happens to live three hours away from my colorist — I’m no stranger to purple shampoo and other violet-tinged hair care essentials. These products are famous for fighting brassiness and keeping blonde strands toned and bright, and I use them religiously in between hair appointments. But at my last color session, my stylist revealed that the grey, muddy tone my highlights had taken on may have actually been caused by my beloved purple products. Yes, purple shampoo could be making your blonde hair look darker — but don’t worry, it’s fixable.

“Many people believe that blonde hair turns brassy over time because toners have faded out,” Dell Miller, the Master Colorist at Spoke & Weal salon in West Hollywood and the guy behind Kate Bosworth's blonde (and mine), tells TZR. “While this might be partially true, it’s not entirely the case.” Miller maintains the real culprit is mineral buildup.

“There are a significant amount of minerals in our shower water that can get lodged into the hair cuticle, giving the hair more of a yellow finish,” he says. “This is caused by copper in pipes, especially in older buildings, or even chlorine in [the water supply].” The colorist adds that air pollution and too much time in the sun can contribute to the gradual “yellowing” of blonde strands, too.

While the violet tones in purple shampoos can help bring blonde back to life, it does this by adding more toner; in effect, covering up the mineral coating on the hair cuticle. The more you shampoo with tone-correcting products, the more buildup you create — and the darker your blonde looks. “Chemicals start to build up as you layer on more [toner], making it overcrowded and muddy with layers of product and minerals,” Miller explains.

Instead, you should aim to strip away those minerals with a clarifying treatment to reveal your most radiant blonde. “This can be done by using detoxifying shampoos or Malibu treatments,” Miller tells TZR. “Malibu treatments essentially involve vitamin C, which goes into the hair and attaches to any mineral or pollution.” To use, sprinkle the powdered mixture into hair while lathering up with hot water and shampoo. “Using friction to massage and scrub the product through the hair begins to release any build up, exposing the actual color of your hair," he says.

Want to take it a step further? Install a shower head filter to prevent mineral buildup in the first place. “A shower filter is just as important as your purple shampoo in keeping hair fresh and your color bright,” Sara Douglas, the co-founder of VitaClean HQ, tells TZR. “Bacteria, iron, rust, and copper can build up in your shower water and leave your hair looking dull and lifeless" — which is exactly why she launched VitaClean, arguably the chicest shower filter in existence.

“The VitaClean ceramic balls and microfiber cloth help combat this effect by catching these substances before they touch your skin and hair,” she says. And the brand’s plant-based gel filters have vitamin C built right in. “This helps to soften the shower water, infusing it with vitamins and encouraging softer, shinier hair,” Douglas tells TZR — not to mention, keeping your blonde in check.

Once your hair is sufficiently stripped of brass-causing buildup, you’re able to see if blonde strands actually need a toner touch-up. “You may follow this with a little purple shampoo to refine the remaining tone,” Miller says. “This process allows your hair to remain as bright and light as it was when you first got your color done.”

See below to shop TZR’s picks for the best blonde-brightening essentials.

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