Olaplex’s No. 9 Serum Has Saved My Frazzled Hair

If your hair is in a bit of a sorry state, you're not alone. This past year has once again afforded us the luxury of booking into salons for major color changeups, fresh new haircuts, and the opportunity to style hair in multiple ways. But things like bleach, dye and heat can all take a toll on strands, leaving them fried and over-processed.

If you were to ask any colorist or stylist for advice on how to get your hair back in tip-top condition, it's highly likely they'll point you in the direction of Olaplex. Though not without controversy recently (a lawsuit filed against the brand earlier this year alleges its products can cause hair loss), Olaplex products remain the gold standard for repairing broken bonds and making dry, damaged hair feel brand new.

I have a confession to make, though. While adored by many, I could take or leave Olaplex numbers 3 through to 7. In my honest opinion, the game really changes when you reach No.8 (the Bond Intense Moisture Mask) and if you're a Refinery29 regular, you'll know I rarely stop harping on about its smoothing, repairing and shine-enhancing benefits. But I can be lazy. I don't have the time nor energy to get out of the shower, apply the mask, wait for it to work its magic and then rinse it out. That's why I was intrigued by the new Olaplex No.9 Bond Protector Nourishing Hair Serum and its promise to grant my need for speed.

Launched in 2022, the brand's first ever leave-in serum contains Olaplex's star ingredient for fusing broken bonds back together: bis-aminopropyl diglycol dimaleate. Don't let the complicated name throw you off, though, as it makes hair soft, shiny and a lot easier to manage. According to Cult Beauty — one of Olaplex's stockists — the serum's benefits are endless and include: frizz control, detangling, shine bounce, curl and wave retention and the ability to shield strands against heat and pollution (the latter of which can make hair look dull and feel coated). Simply rake a pump or two of the jelly-like serum through towel-dried hair and leave it to air-dry or blow-dry as preferred.

After a stint with bleach and blue hair dye, my lengths were a little worse for wear. No matter how many trims I booked in for, the ends felt like straw, and as it was so dry, it was always frizzy. I'm after softness, shine and movement. While there are countless products that gave me a leg up (ARKIVE The Good Habit Hybrid Oil and Kérastase Elixir Ultime L'Original Hair Oil), Olaplex always piques my interest.

At $30 for 90ml, the price is somewhere between drugstore and luxury. I have a lot of hair but half a pump (be careful, it's easy to go overboard) was all I needed to coat each strand. I pulled the product through damp hair and gave it a once-over with a wide-tooth comb to make sure it was evenly distributed before rough-drying with a hairdryer.

I noticed how much softer my hair felt as I was blow-drying it. With other products, it would typically feel tangled at this stage. With some difficulty, I'd have to pull a brush through it afterwards. Instead, I just used my fingers. After washing my hair, it tends to frizz up at the root, and while I noticed a few stray strands here and there, my hair appeared much smoother. Like magic, my bleached, parched split ends were a lot softer to the touch.

I experienced the real benefits the next day, though. At first, I was skeptical that this clear, unassuming serum could help define my natural waves as the product description suggests — but it did. Instead of killing my hair with straighteners (or whipping it up with a claw clip to hide the bleach damage, which I've been doing lately) I pulled my fingers through my lengths and flipped it to one side. My waves fell pretty perfectly with added bounce, volume and shine. You can use the serum on dry hair, too, to smooth down flyaways, and to dial up the glossiness.

After a couple of goes, I went back to the label to see which other ingredients might also have the ability to transform my frazzled hair in this way. First up, panthenol. This keeps moisture under lock and key in the hair, improving the feel and giving it a glossy finish. Then there's sodium hyaluronate (a version of hyaluronic acid) which hydrates hair deeply. As the product is entirely clear, it's great for all hair colors, especially blonde. Not long ago LA colorist Justin Anderson dropped the bombshell that tinted hair products may build up and change the color of lighter hair over time. This won't.

Alongside No.8, I really do think I've found my new favorite Olaplex product in this easy, rejuvenating hair serum, and I'll continue to use it til the last drop. If you'd rather spend a little less, try The Inkey List's Hyaluronic Acid Hydrating Hair Treatment, which hydrates hair and smoothes frizz, or the Andrew Fitzsimons Virgin Repair Restructuring Serum for Damaged Hair packed with proteins to strengthen brittle strands.