On days when my closet is full of clothes I hate, or my eyeliner is off, or when there’s a zit the size of Mt. Vesuvius on my chin, the one thing I can always count on is my hair. I’m not trying to brag or anything but, I have pretty great hair. It’s thick but not unruly, grows at a pace that shocks my stylist at every appointment, and it’s healthy despite my regular balayage sessions and constant heat styling. I was once called “Becky with the good hair” by a girl in a bathroom bar, and it is still one of my proudest moments.

For the reasons I just listed, I haven’t strayed from my go-to shampoo and conditioner (Pureology Hydrate ($35), for anyone who is curious) for three whole years. I was convinced that switching up the combo couldn’t make a huge difference, since my hair wasn’t exactly in desperate need of a total makeover. But a few months ago, the Function of Beauty Shampoo and Conditioner Set ($36) kept finding its way into my feed, and just like that, curiosity kicked my sweet little Pureology set to the curb.


A Little About Function of Beauty

Created by MIT engineers and a cosmetic chemist, the brand offers a customizable and made-to-order approach to haircare. It’s like Build-a-Bear for haircare but with beakers and serious science. There are no pre-made mixes or one-size-fits-all options in sight. Every set is truly custom — we’re talking one of 12 billion potential formula combinations, given your hair type and your goals. Plus, all formulas are paraben, sulfate, and cruelty-free and come in a bottle made of recycled packaging.

How to Create Your Custom Blend

First, fill out the quiz on FunctionofBeauty.com. This one is thorough with a capital T. You’re asked to assess your hair profile (is it curly or straight? Fine or coarse? Is your scalp oily or dry?). Then comes the fun part: You get to pick five goals for your hair. Mine were deep conditioning, adding shine, color protection, thermal protection, and to lengthen. As you make your selections, the quiz tells you which active ingredients will be added to your formula to meet that goal. So deep conditioning will add shea butter and quinoa protein, while thermal protection adds grapeseed oil and chestnut extract. Finally, you choose a color, a label, and a fragrance (also very fun).

More proof that this brand is committed to customization: You choose between an eight-ounce set for $32 and a 16-ounce set for $42, and you can even mix and match a larger shampoo with a smaller conditioner or vice versa for $38. You can also opt to purchase a shampoo or conditioner on their own. Bonus points: You can tweak your formula with each batch — so if you color your hair and want to add protection for that, you can.


The Verdict: This Stuff Straight-Up Works

During Shower: The shampoo lathers nicely, but if you’re expecting piles and piles of frothy lather, think again. The texture has a nice slip to it which makes it easy to rinse out. The conditioner is surprisingly so lightweight. It feels super silky and hugs each strand so you can let it set for a minute or five.

Post Shower: I blasted my hair with some heat protectant spray and got to work blowing it out. Although I typically just let my hair air dry, I had a little extra time that morning, so I went full-on DryBar with it and busted out a round brush too. The result was sort of bonkers. My hair glided through the brush with total ease and even took 15 minutes less than usual to style. It was bouncy and glossy and stood up to the heat of my Harry Josh Pro Dryer ($170) like a champ.

When I washed my hair with the set a second time, I let it air dry, and that’s when I became really, truly impressed. Typically, when I let my hair air dry I get this dreaded helmet of frizz hovering over my hair, no matter how many anti-frizz serums or creams I apply. Additionally, I have these annoying little baby hairs on my hairline that coil straight up and make me look like an insane person. A couple of my passes with my flat iron usually obliterates both of those problems. But after using this set, both my frizzy and coiled baby hairs became non-issues. It was a magical moment for me, my flat iron, and my bathroom mirror.

The After Effect: Here’s where I think the Function of Beauty set really outdoes itself. I can normally stretch a couple of days out of every wash. After using this set, I found myself reaching for less product each day because I didn’t feel like my hair really needed any help from a wave spray or shine serum and less product meant less build-up. This set gave me a whole extra day between washes — and I’m talking a hair-down kind of day. Throw in one more day in a topknot and that’s a total of four days of non-greasy-looking hair from one wash (AKA a MIRACLE). That’s something my old go-to shampoo and conditioner has never been able to pull off.


If you’ve ever felt limited by the one-trick-pony shampoos and conditioners on salon or drugstore shelves that only claim to give you one thing (“volume or hydration, but never both”), then I would definitely recommend giving this a try. It actually targets your pain points, no matter how all over the place they may be. Not to mention, we live in a world where you can customize your fragrances, your jeans, your purse — so why not your haircare too?

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