QOOL-epilation® by LINLINE

Painless, selective hair removal for any skin type—even tanned skin

QOOL-epilation® is LINLINE’s nanosecond, pulse-train method for permanent hair reduction. Instead of one hot, long pulse, QOOL uses millisecond-long trains of Q-switched nanosecond pulses at 1079 nm that concentrate energy inside the hair, not the skin. Patients usually describe only a light pinching when a hair enters the beam; no anaesthesia or contact cooling is required. 

How it works 

Non-linear absorption in melanin. Each nanosecond pulse makes hair melanin briefly absorb far more light than usual, so energy stays in the hair shaft. Pulse gaps are matched to thermal relaxation, letting hair heat up while skin cools. 

• Photoacoustic + photothermal synergy. The first pulses create tiny acoustic micro-explosions that lift cuticle scales and fragment cortex pigment, forming a thin gas layer around the shaft—like a “thermos” that blocks heat from escaping into the skin. Subsequent pulses step-heat the hair toward the bulb/bulge, coagulating the growth zone while sparing surrounding tissue.
• Deep reach. The 1079 nm wavelength penetrates to deep follicles, and the pulse-train parameters (duration, spacing, energy) are tuned to hair colour and skin type. 

Why clients choose QOOL

• All skin phototypes—even with a tan. With energy confined to the hair, normal skin is left largely untouched, so sessions can be done before or after sun exposure without the classic restrictions of long-pulse/diode systems.
• Comfortable & no downtime. Most areas (face, underarms, bikini) feel like light pinches; there’s no anaesthesia, pain meds, or chilled gel.
• Designed for difficult hair. The mechanism supports work on light or red hairs (often with a tailored protocol—see below). 

How QOOL differs from classic diode/long-pulse methods

• Diode and long pulse are photothermal: they heat skin to damage the follicle and often requires sun-exposure limits and contact cooling. QOOL uses nanosecond pulse trains with strong photoacoustic contribution and fewer tanning constraints.
• QOOL’s “thermos” effect reduces heat flow into skin, enabling lower fluence yet effective follicular coagulation—more comfort, less downtime.