Olaplex N.5 Bond Maintenance Conditioner is a highly nourishing and reparative conditioner developed with patented Olaplex Bond Building technology to hydrate and protect the hair. It contains an active ingredient Bis-aminopropyl diglycol dimaleate that works at molecular level to dramatically improve the hair strength, repair damage and protect the hair. It repairs, strengthens, and moisturizes hair prone to damage or dryness. Hair is made up of the fibrous protein, keratin and held together by bonds. Hydrogen and salt bonds are physical bonds and are easily reformed by changes in pH, water and/or heat. Disulfide bonds are chemical covalent bonds. These bonds cannot be broken by water. Millions of disulfide bonds give hair its structure, strength, and stability. When hair subjected to heat styling, color or chemical treatment, sometimes brushing & tugging or due to weather may lead to breakage of these disulfide bonds. When these disulfide bonds are broken, hair is damaged and can appear dry, frizzy, and brittle. Olaplex N.5 Bond maintenance color safe conditioner works in a unique way to repair broken bonds and restore healthy hair quickly and effectively. It is recommended to pair with N.4 Bonding maintenance shampoo for softer, shinier, healthier-looking hair with every wash. Color safe. Study showed that 91% smoother, better detangling, more conditioned and 66% reduction in breakage after the use of Olaplex No54 Bond maintenance conditioner.