To understand the difference between remy human hair and non remy human hair, it is important to understand composition of the hair strand.

Each hair strand is made up of the medulla, cortex and cuticle. The cuticle is the outer most layer of the hair strand and is made up of hard, shingle-like cells that provide protection to the inner layer of the hair.

Naturally-growing, biological hair grows with the cuticles running in the same direction from root to tip. When the sourced hair is cut, the bundle of hair must be kept with the cuticle running in the same direction to be considered remy human hair.

Non remy human hair is hair bundles that are collected from multiple sources and cannot guarantee that the cuticle is running in the same direction.

For this reason, the hair is treated to partially remove the cuticle. If this process is not done properly, matting and inversion will occur.