The popular belief that chronic stress triggers hair loss is increasingly supported by concrete biological evidence from recent research.

Mechanism

Chronic stress activates the hypothalamic-pituitary-adrenal (HPA) axis, increasing cortisol secretion. Cortisol can trigger follicles to prematurely shift from the anagen (growth) phase into the telogen (resting) phase. Animal studies have shown that corticosterone (cortisol's rodent equivalent) suppresses expression of the Gas6 protein, which activates hair follicle stem cells.

The Inflammatory Pathway

Elevated cortisol can shift the immune system toward producing pro-inflammatory cytokines (such as TNF-ฮฑ and IFN-ฮณ), which can negatively affect the hair cycle's transition from telogen back to anagen.

A Self-Reinforcing Cycle

A 2025 review published in JAAD Reviews found that while stress triggers telogen effluvium, the psychological distress of watching hair fall out further amplifies the stress response โ€” creating a self-reinforcing cycle.

Relevance to transplantation: Stress-induced telogen effluvium is temporary and usually reversible โ€” so for active, newly-onset diffuse shedding, managing stress and allowing time for recovery is recommended before considering surgery.