Anagen
The active growth phase, during which the follicle produces a hair shaft.
QBio Science · Hair-follicle biology
without turning biology into a product promise.
A provider reading guide to follicle phases, the dermal papilla, and the perifollicular environment.
The cycle
Growth, regression, and relative rest.
Hair follicles cycle through biologically distinct phases. The simplified three-phase model is useful for orientation but does not support a finished-product claim.
Catagen
A short regression phase characterized by coordinated structural change.
Telogen
A period of relative quiescence before the follicle enters a new cycle.
Source: Krause & Foitzik, Biology of the hair follicle: the basics.
Dermal papilla
A signaling niche at the base of the follicle.
The dermal papilla is a specialized mesenchymal cell population involved in epithelial–mesenchymal communication and the regulation of follicle characteristics across the cycle.
Read the dermal papilla reviewReading the Gro table
Protein names point to literature questions, not cosmetic outcomes.
The Gro characterization table reports measured abundance, then gives literature-framed descriptions of follicle biology. It does not state that the finished product changes the hair cycle.