I’d be lying if I said my blonde was natural. I was an almost-bald baby with hair so light my parents were left wondering if I’d ever have hair. I’m now a 30-something adult, who definitely has hair, but those blonde locks of my youth are fully gone. In their place is regular hair appointments and a lot of salon-painted foils. While I’ve definitely strayed from my blonde base — most notably after break ups, major life events and particularly boring periods in my life — it’s never long before I’m running back to the salon, clinging to photos of hair past.

Five years ago I promised myself I wouldn’t change my hair colour again — and while I’ve stayed mostly true to that, I’ve been amazed at the maintenance that goes into keeping blonde hair, well, blonde.

However, there’s one product that has helped extend the lease on my blonde locks between salon visits: purple shampoo. Almost every haircare brand offers a blonde shampoo, promising to eliminate brassiness and give you shining, icy locks — below, I’ve rounded up the benefits of purple shampoo as well as some of the best ones you can buy.

$50 at Sephora

Why use purple shampoo?

Purple shampoo helps neutralize brassy tones to give you a cool blonde finish. The science behind this product is pretty basic: purple is opposite yellow on the colour wheel. This means when purple is applied to yellow, it effectively neutralizes it and cancels out any brassy hues.

A popular misconception is that purple shampoo will lighten your blonde, but unfortunately the lightness of your hair is completely up to your stylist. While purple shampoo is definitely a blonde hair essential, it won’t bleach your hair or lift the tone any further than your stylist already has.

How to use purple shampoo

The application of purple shampoo is similar to any other shampoo or in-shower hair mask — but you do have to be careful both with how long you leave the purple shampoo on your hair and how often you use it.

Like always, wet your hair and lather into your roots. Most purple shampoos will recommend leaving the product in your hair for several minutes to work its magic. If it’s your first time applying purple shampoo, keep to the lower end of the recommended time until you’re comfortable with its strength.

When introducing purple shampoo to your haircare routine, it’s also recommended you only use it once a week. Due to the neutralizing nature of purple shampoo, if used too often, it can dull your hair’s shine and dimension. While it can be tempting to use it with every wash for a Marilyn Monroe-inspired icy blonde, once a week seems to be the sweet spot to maintain your blonde without dulling your stylist’s hard work.

Sometimes purple shampoos can be drying on your hair. I’ve found it’s best to do a moisturizing hair mask after I rinse out my purple shampoo treatment.

So, do blondes have more fun? I’m not sure, but we sure do put a lot of effort in to trying. To save you the trial and error of finding the best purple shampoos, I’ve rounded up my favourites at every price point.

$5 at Amazon

Rating: 4.3 stars

Promising review: When it comes to purple shampoos, this is one of the originals. Loved for its ability to neutralize “lemon yellow roots,” shoppers say the result is “brass-free, ashy blonde.” However, reviewers recommend buying a moisturizing conditioner because this shampoo can “leave hair feeling a little dry.”

$27 $30 at Amazon

Rating: 4.6 stars

Promising review: Some reviewers say this affordable shampoo “is the best purple shampoo on the market.” While most liked the results, some warned the scent “is too strong and smells a bit strange.”

$41 at Sephora

Rating: 4.1 stars

Promising review: “I’m so impressed with how refreshed my blonde looks. I had very bold blonde money pieces put in last week and some of my hair didn’t take,” wrote one shopper. “I used the Olaplex blonde shampoo, and it actually toned the pieces beautifully. I highly recommend.”

$50 at Sephora

Rating: 4.4 stars

Promising review: “The best! Out of all the purple products out there to keep my blonde hair looking its best, this is the winner. I’m happy with the quality of this shampoo,” writes a shopper. “It smells very nice and not strong like some other purple shampoos can. It’s also the only one that can get the brass/yellow out of my hair.”

$70 at Sephora

Rating: 4.8 stars

Promising review: “I have never used amika products prior to this but when I saw this set I decided to try it out because I was almost out of my current purple shampoo… it is a really deep purple and after leaving it on for about four minutes , my hair felt super soft and completely banished any remaining brass. I think this combo of products has been the best so far at removing brassy tones while keeping my hair soft and moisturized, something I don’t normally get with my regular purple shampoo. “

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