When you work in beauty, a big part of the job is trying out new products, no matter if you already have your face moisturizer or your red lipstick. Which isn't to say you can't have a few standbys, but the name of the game is experimentation. It's a rare experience, then, to find yourself coaxing out the last drops from a moisturizer tube, or fumbling with a tiny stub of eyeliner. [Cue violins] But when we do finish something, it means we must really love that product. Hence the feature, Things We Finish, in which we talk about the products that we squeeze, scrape, or shake 'til there is nothing left. Today we hear from Glossier's Email Manager, Nina Blass:

Something I’ve learned the hard way: Doing things to your hair is a lot easier than undoing them. Two years ago, I made the impulsive decision to go from dark brunette to very light, ashy blonde. Apart from a few bad box dye experiments in high school, I was brand new to the world of hair color—and (naively) unprepared for the maintenance involved. I told myself that highlights would be easier to keep up with than a double process, but I didn’t think much about what bleach would do to the texture of my hair. Oops.

After a few months of being blonde, it felt like my hair was growing itself into a nest. Shampoo (even purple) made it feel like straw. Co-washing worked for a while, but eventually I found myself unable to run my hands through my hair, wet or dry. Experiments with coconut oil left me worse off than before. My head got gross, and I didn’t have the patience for complicated recovery routines. I wanted a silver bullet.

Turns out such a thing actually exists: Protein! But protein treatments can make damaged hair even more brittle, so it’s tricky territory. That’s not the case with Kevin Murphy Re.store, and I could feel the difference minutes into using it. After massaging the product into my scalp in the shower, I could get my fingers through wet hair with zero effort. It felt slippery and smooth and clean for the first time in months. After rinsing and air drying, my hair looked healthy in a way it hadn’t since I dyed it. The natural wave came back and lasted through the rest of the week.

Now I leave it in for a few minutes while showering instead of using shampoo or conditioner, but just once a week (it’s not meant to be an everyday product). I’ve started looking forward to the days when I’m “allowed” to use it because my hair feels that much better after—and because it smells so good. It’s juicy in a fresh (not bottled) way, like pineapple and papaya and going outside.

But that’s it. One product, one step, once a week. The only downside: The opaque bottle means even with rationed, spaced-out application, the inevitable end comes as an unwelcome, sputtering surprise. Upside: You have seven days to track down another.

—Nina Blass

Photographed by Tom Newton.

More hair products we've loved to death: Read about Claire's daily blond shampoo and Brennan's preferred lightweight hair mask—plus more of the Things We Finish series.