For years, purple shampoo has been the anti-brassiness poster child when it comes to minimizing those inevitable, unwanted warm tones that occur slowly but surely in lightened strands. (In case you’re curious, frequent washes, sun exposure, heat-styling, and the minerals and chemicals found in our water can be held responsible.) Alas, to keep lightened hair looking as fresh, cool, and un-yellow as possible, purple can save the day. Since purple shades are best at canceling out yellow tones, those violet-hued shampoos are typically more effective for people with blonde or gray strands, and—plot twist—blue-toned shampoos are actually the far more strategic choice if you have brown hair, be it a dye job or your au naturel hue.
I’ll be going into more detail below, but since blue naturally cancels out orange, which is typically the underlying pigment in brunette hair, it’s a better option than purple if you’re looking to really combat that orangey brassiness that starts sneaking in a few weeks post–color job. Good to know, right? In addition to explaining what exactly blue shampoo is and how exactly it differs from purple shampoo, I’ve also rounded up the 12 best blue shampoos on the market right now. (Trust me—as someone who has been highlighting and coloring my hair since elementary school, I know my way around the color-correcting space.) Keep scrolling! Everything you’ve ever wanted to know about blue shampoo is just below.
As I touched on above, blue shampoos work by canceling out and neutralizing orange and/or copper hues that occur over time in brown hair. Essentially, these shampoos act like handy-dandy color correctors by depositing cool, blue pigments on top of your strands to help rebalance your color if it’s been a while since your last color job. Another hot tip? Since brassiness can be exacerbated by all of the minerals and chemicals found in our water, it’s a worthwhile idea to invest in a shower filter along with a blue shampoo for an extra-potent one-two punch of protection. (I swear by this one from T3!)
Honestly, both purple and blue shampoos will counteract encroaching warm tones in our hair. Blondes can use either, and brunettes can use either. However, blue shampoos are specifically fabulous at neutralizing orange pigments (which are typically found in brown hair), while purple shampoos are specifically fabulous for fending off the yellow/golden tones synonymous with blonde. I’ve been bleaching my hair for a good part of the 27 years I’ve been on planet earth, and I’ve had great results from both. Really, it comes down to personal preference.
A word to the wise? Less is more. Both purple and blue shampoos only deliver temporary results, but it can be easy to overdo it. Experts recommend only using your pigmented shampoo every three washes or so to avoid imparting an actual purple or blue tinge to your hair. Additionally, pay heed to how long you’re letting it sit—after you’ve massaged and worked it into your strands, let the shampoo marinate for one to two minutes if you have less brass but have porous hair. Leave it on and a little longer (anywhere between three and five minutes) if you have more brass and less-porous hair. More than likely, it will take a little bit of tinkering and a few applications until you find the groove with your new blue shampoo.