Hair naturally grows in cycles, with each strand renewing at its own pace. Most of the time, hair is in its active growth stage, which can last several years. During this phase, hair strands grow steadily and appear thicker and stronger, and the majority of hair on the scalp is usually in this stage at any given time.

As part of the natural cycle, hair then moves into a short transition stage, followed by a resting phase that lasts a few months. During this period, the existing strand remains in place until a new strand begins to grow and gradually replaces it. This is why daily hair shedding is normal, and losing around 50–100 strands a day is generally considered part of a healthy hair cycle.