Bumble and bumble. Bond-Building Repair Oil Serum 48ml (1.62floz) UK Delivery

Hair is held together by different types of bonds, which define its strength, shape, and flexibility. Chemical processing, bleaching, heat styling, and rough brushing can damage these bonds. Bond repair products, also called bond builders, work to rebuild or reinforce these bonds. Not all of them work the same way: some use ingredients designed to reconnect broken bonds directly, while others use acids, like citric or lactic acid, to lower the hair's pH and smooth the cuticle, reducing friction and breakage. They're generally aimed at dry, damaged, or chemically processed hair.

A heat protectant is a leave-in product applied before using a hair dryer, flat iron, or curling iron that helps reduce damage caused by heat styling tools. Its ingredients form a film over the hair that slows down and spreads out the heat, so the hair warms up more gradually, which helps limit moisture loss, dryness, and breakage.