Olaplex No.9 Bond Protector Nourishing Hair Serum Review

No matter how regularly I use reparative hair masks, spritz in hydrating leave-in conditioners, and switch out my hairdyer for air-drying, my hair’s natural texture means that it always looks somewhat frazzled. But as someone that is decidedly unskilled in the hair-styling department and rarely has time to spare to experiment with different hot tools, I tend to just leave my tangle of flyaway waves to do their own thing. However, recently an Olaplex product landed on my desk that has become something of a game changer for me and my unruly hair: Olaplex No.9 Bond Protector Nourishing Hair Serum.

Despite not enjoying the same furore as the viral Olaplex No.3 Hair Perfector, this little-known gem from the Olaplex line-up is seriously impressive and takes my hair from dull and dry to sleek and shiny with very little effort required. And while I’ve tried hundreds of hair serums in the past, this is far superior to many of the formulations on the market right now.

Ahead, I break down exactly what Olaplex No.9 is, how it works, and share my before-and-afters of this impressive serum.

What is Olaplex No.9?

Far more than a standard hair serum, the Olaplex No.9 Bond Protector Nourishing Hair Serum is infused with the brand’s patented technology and their star bond-repairing ingredient bis-aminopropyl diglycol dimaleat. It’s this very ingredient which is found in the brand’s iconic Olaplex No.3 repairing and strengthening treatment and actually works to repair damaged strands.

Besides that, though, this serum offers so much more—its an antioxidant formulation which works to neturalise free radicals and protect hair from the damage of pollution (perfect if you’re a city-dweller like me) and it also provides heat protection if you blow-dry or heat style your hair. On top of that it boosts shine, reduces tangles, and minimises static without any silicones or sulphates, and it even improves the style memory of your hair which means your style will stay in place longer between washes. It’s an impressive array of benefits and even more impressive that it actually delivers on all fronts.

Olaplex No.9 Bond Protector Nourishing Hair Serum

How to use Olaplex No.9?

As someone that is haphazard at best when it comes to a hair routine, I love the versatility of this serum which can be used in a multitude of ways. To really reap the heat protection and style memory that it offers, it’s best when applied to damp hair—I tend to smooth about half a pump of the serum through towel-dried hair, starting at the ends and working upwards. Unlike other serums that I’ve tried in the past, I find that it never makes my hair look greasy when applied at the roots.

While I’ve found that blow-drying hair after application makes for the smoothest, most glossy finish, it also makes for a great air-dry product. I often leave my hair to dry while I get ready in the morning (because who has time for a full blow-dry before 8am?) and my waves always look more defined, lifted and bouncier when I’ve used this. And if you need a little smoothing or extra shine on second (or third) day, then applying a little of this serum to dry hair works well too—it reduces static, controls flyaways, and provides expensive-looking shine.

Before using the Olaplex No.9 Bond Protector Nourishing Hair Serum

This is my hair pre-hair wash on a typical day, before using Olaplex No.9. I had washed it a few days before this and had added in a few curls with a wand after rough-drying it. However, you can see that curls have fallen out and my natural waves and frizzy texture can be seen in full force. Plus, it’s worth noting that I am majorly overdue for a haircut as it’s so dry at the ends of my hair—so the serum has a lot of hard work to do.

After using the Olaplex No.9 Bond Protector Nourishing Hair Serum

I applied the Olaplex No.9 on freshly-washed, damp hair and left it to air-dry. My hair felt incredibly soft—something that I don’t often notice unless I’ve had a professional blow-dry—and looked so much sleeker and shinier than usual. I’m most impressed by the results that it had at the ends and mid-lengths of my hair, where that patented technology clearly got to work repairing and smoothing the damage. Yes, there’s still natural texture there and some of the frizz that my hair will always have, but my hair has never looked so good when left to dry naturally.

Honestly, I don’t think I’ll be without this in my haircare routine from now on.

Mica Ricketts is a freelance beauty editor and contributor to Marie Claire. She has written for titles including Refinery29 and Who What Wear UK, and also works with beauty brands on content messaging and marketing copy. She was previously Who What Wear UK's beauty editor. As someone that has tried basically every acne product on the market, she has a particular passion for debunking skincare myths and finding products that work. Plus, with two small children at home she is all about time-saving beauty routines that boost glow and disguise dark circles.