Laser hair removal is least effective on follicles in what stage of development?

Laser hair removal targets the anagen phase of hair growth, during which the hair is actively growing and is most firmly attached to the follicle. This is when the hair has the greatest amount of melanin, making it more responsive to the laser’s light energy.

In the telogen stage, which is the stage of hair growth where the hair is resting and not actively growing, the follicles are less sensitive to the effects of laser light. The hair itself may not be present or is more likely to be in a phase where it's ready to shed, making it not an ideal target for laser hair removal. This is why laser procedures are least effective on follicles in the telogen phase compared to those in the other stages of development, where the hair can be effectively treated and removed.

The exogen stage involves hair shedding, the catagen stage is a transitional phase where hair growth slows down, and while these stages present challenges, the telogen stage is definitively when follicles are least affected by laser treatments.