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A handful of hairstyles stood out at the 2026 Emmys, but Nicole Kidman‘s effortless, undone bun is one we found ourselves bookmarking and wondering how to recreate. One product behind Kidman’s enviable volume? The K18 AstroLift™ Reparative Volume Spray, a hair-thickening spray that’s lightweight, volumizing and perfect for fine hair.
Hairstylist Lorenzo Martin sprayed the formula onto Kidman’s towel-dried hair at the roots for an instant lift, and we’ve officially added the product to our fine-hair arsenal.
Get the K18 AstroLift™ Reparative Volume Spray for $46 at Amazon! Please note, prices are accurate as of the publishing date but are subject to change.
You may know K18 for its viral leave-in mask, but this spray is worth exploring if you’re after thicker-looking hair. Like the mask, this formula contains the brand’s K18PEPTIDE™, a patented peptide technology designed to address damage within the hair while you style. Meanwhile, a hair-fiber volumizing blend works on the outside of strands to make them look and feel thicker.
According to K18, the blend can increase the diameter of individual hair fibers by up to 25%, helping create fullness from roots to ends rather than concentrating volume at the crown.
Plus, if stiff, crunchy hair is why you tend to avoid volumizing products, this one was specifically formulated with touchability in mind. Rather than relying on a heavy coating to prop hair up, AstroLift creates flexible, movable body that can be built up depending on how much volume you’re after. The formula is also humidity-resistant, which helps keep that freshly styled fullness from immediately falling flat.
It’s also refreshingly low-maintenance when it comes to application. You can use the spray on either dry or towel-dried hair, so it works whether you’re starting with a fresh wash or simply trying to revive second-day strands. Shake the bottle, hold it about four to six inches away and mist it generously through the roots and hair. Heat isn’t required for the formula to work, but K18 recommends blow-drying after application if you want to maximize volume (which makes Martin’s technique on Kidman easy to recreate at home).
An Amazon reviewer said it’s “given life to my fine hair” while another shopper noted: “This stuff actually works! I have super flat hair and super thin. This stuff makes my hair seem thicker, especially at the top.” According to another shopper, it also adds “nice texture” with “no crunch.”
Kidman’s red carpet bun may have had a celebrity hairstylist behind it, but the volume trick itself couldn’t be much easier to copy. Shop the K18 AstroLift™ Reparative Volume Spray on Amazon and put Kidman’s root-boosting secret to the test!
Get the K18 AstroLift™ Reparative Volume Spray for $46 at Amazon! Please note, prices are accurate as of the publishing date but are subject to change.
