Over the past eight years, I have spent hundreds of dollars and countless hours chasing volume for my limp, fine, straight hair. I’ve tried volumizing mousses and texturizing sprays. I’ve tried blow-drying my hair upside down and sideways and every angle in between. And all I’ve gotten for my tireless efforts is a depleted wallet and surprisingly buff arms.But everything changed when I found Ouai’s Fine Hair Shampoo while working on Wirecutter’s guide to the best shampoo. After my first shower with Ouai, I noticed a difference: My roots had a subtle lift and natural buoyancy. My scalp felt clean and buildup-free. Now, four bottles and six months of regular use later, I can report that the volume actually lasts.