Nicole Kidman Swears By This Thickening Spray for Luxurious Volume

A few hairstyles truly stood out at the 2026 Emmys, but Nicole Kidman‘s effortlessly styled bun caught our attention, leaving us eager to replicate it. One secret behind Kidman’s stunning volume? The K18 AstroLift™ Reparative Volume Spray, a lightweight, volumizing hair-thickening spray that’s perfect for fine hair.

Hairstylist Lorenzo Martin applied the spray to Kidman’s towel-dried hair at the roots to achieve instant lift, and we’ve officially added this product to our collection for fine hair.

Grab the K18 AstroLift™ Reparative Volume Spray for just $46 on Amazon! Please note, prices are accurate as of the publishing date but may change.

You might be familiar with K18 for its viral leave-in mask, but this spray is definitely worth trying if you desire fuller-looking hair. Similar to the mask, this formula contains K18PEPTIDE™, a patented peptide technology designed to repair hair damage while styling. Additionally, a hair-fiber volumizing blend works to enhance the appearance and feel of thickness on the strands.

K18 claims that this blend can boost the diameter of individual hair fibers by up to 25%, providing volume from roots to tips rather than just at the crown.

Moreover, if you typically steer clear of volumizing products due to stiff, crunchy results, this one is specifically crafted with touchability in mind. Instead of relying on a heavy coating for support, AstroLift delivers a flexible, movable body that can be built up depending on your desired volume. The formula is also resistant to humidity, ensuring that your freshly styled fullness lasts longer.

Application is surprisingly low-maintenance. You can use the spray on either dry or towel-dried hair, making it suitable for freshly washed hair or reviving second-day strands. Simply shake the bottle, hold it about four to six inches away, and mist generously at the roots and throughout your hair. While heat isn’t essential for the formula to work, K18 recommends blow-drying post-application for maximized volume, making Martin’s method on Kidman easy to replicate at home.

One Amazon reviewer mentioned it had “revived my fine hair,” while another customer commented: “This stuff genuinely works! I have very flat and thin hair, and it makes my hair appear thicker, especially at the roots.” According to yet another reviewer, it also adds “great texture” without any crunchiness.

While Kidman’s glamorous bun may have been crafted by a celebrity hairstylist, the volume-enhancing technique is simple enough to replicate. Shop the K18 AstroLift™ Reparative Volume Spray on Amazon and try out Kidman’s root-boosting secret!

Get the K18 AstroLift™ Reparative Volume Spray for just $46 at Amazon! Please note, prices are accurate as of the publishing date but may change.