The science of hair
The NIOXIN definition of hair thinning is having fewer hair strands, finer hair strands, or a poor scalp environment for hair to grow from. Each of these three signs, developed from scientific observation and stylist and consumer insights, has a basis in biology.
FINER HAIR STRANDS
When hair goes through its full lifecycle, it looks full and thick. However, changes in our diet, stress levels, health and living environment can shorten the lifecycle, preventing it from maturing and causing regression to smaller, finer hair.