All products featured on Glamour are independently selected by Glamour editors. However, when you buy something through our retail links, Condé Nast may earn an affiliate commission. If you have flat, ...

Hair trends come and go, but big volume has already become a staple in 2025. We’re seeing it on every red carpet with ...

A 30-volume developer will lighten your hair a bit faster and more intensely than a 20-volume developer would, but not as drastically as a 40-volume. "A lot of people will use 40-volume or 10-volume ...