What Shannon says: "I've been bleaching my hair for over 15 years, and the damage needs a lot of management. The bond-restoring benefits of this purple shampoo means my long hair is left feeling stronger, looking less brassy and is less prone to breakage." 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." 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. Purple shampoo can dry out your hair. Look for one that is formulated to overcome that obstacle, leaving your hair soft, shiny and undertone free. For those with damaged or dry hair, a nourishing toning mask will probably be better for your hair than a purple shampoo.

Whether you were born with blonde hair or you pay for it, it can be tough to get the color just right. Even if it looks perfect the day you color it, it can gradually lose its luster and start to turn brassy. Those yellows, oranges and reds that make blonde hair look less brilliant than you’d prefer are hard to avoid. Just because you use purple shampoo, doesn’t mean you can do away with a toner. If your salon provides that service, use purple shampoo as a supplement. If you color your own hair, look for a toner that can reduce undertones. But Zoe Irwin, creative director at John Frieda Salons, advises clients to be careful as purple-based products can be drying. Session stylist Ali Pirzadeh concurs and recommends using your regularconditioner afterwards."I wouldn't bother with a purple conditioner as well, as you want to make sure your hair is still being nourished."

First, you don't want to use a purple shampoo every day. Our experts suggest swapping one in for your regular shampoo once every few weeks, or when you want to brighten your shade or minimize brassiness or yellowing. As for how to use a purple shampoo, for best results, allow it to sit for three to five minutes before rinsing to fully penetrate the hair.

Don’t use purple shampoo in the first two weeks after your hair has been colored. The hair is more porous following bleaching, making it more likely you’ll get blotchy, uneven results. You don’t have to have dyed hair to benefit from purple shampoo. In fact, those with naturally blonde and naturally silver hair find it reduces undertones. What Katie says: "This is the product I never knew I needed. The Olaplex system is the ultimate product range for protecting and caring for bleached hair. So the idea of a toning shampoo with the Olaplex technology inside is mind-blowingly exciting. It has become a must-have for me, as I use it alongside the rest of the range. I particularly like to use it straight after I've had my colour done when my hair is at its most vulnerable. If you're looking for a product that you can 100% rely on, this is that product." What Sunil says: "A full believer in the restorative and transformative powers of Olaplex, after having recently gone blonde, I was thrilled when they launched this product. It doesn't leave my hair feeling dry - my hair ACTUALLY feels better after using - and the colour payoff is seriously impressive." That’s where purple shampoo comes in. If you look at a color wheel, purple is directly across from yellow, and colors located on opposing sides of the wheel cancel each other out. When purple is applied to your hair, it cancels out the yellow tones, providing that icy blonde color that is seen as the ideal.Wearing suitable gloves, apply to wet hair, lather and rinse well. Repeat if necessary. For maximum benefits, leave second lather on 3-5 minutes. Follow with Total Results So Silver conditioner. When it comes to hair, there’s nothing better than fresh color. The challenge? Maintaining that just-left-the-salon level luster until your next dye job. Blondes in particular may notice signs of brassiness over time. This yellow or orange cast can be caused by a number of things, including "your color oxidizing over time, exposure to UV light, chlorine and even traces of copper in your water,” explains Meri Kate O’Connor, celebrity colorist at Loft 647 in West Hollywood, California. This is where a purple toning shampoo can help. What is purple shampoo good for and what happens when you use it? 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 Shannon says: "I've got to agree with both Katie and Sunil here, this is without question, the best shampoo I've ever used for achieving that icy blonde look. If you have even a hint of brassiness, one wash with this will sort things out straight away. It's so good, in fact, that I highly recommend giving your nails a good scrub immediately after rinsing to avoid any staining." It all depends on the instructions on the specific bottle, but not overdoing it is key. "If you leave a purple shampoo on for too long, your hair will have a blue-purple tinge to it," Irwin cautions.

Those who bleach their hair 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. 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. What Sunil says: "I was recommended this product by a beauty editor with many years of industry experience, so naturally I had to give it a go. IMHO it is THE very best purple shampoo on the market if you want that real shot of iciness. To get my hair blonde, it needs some serious bleaching, and suffice to say, it needs all the help and conditioning it can get. This instantly banishes any trace of brassiness. As long as I dye my hair blonde, there will be a bottle of this in my bathroom."