The Key Role of Melanin in Laser Hair Removal Laser hair removal (especially with 808 nm diode lasers) works on the principle of selective photothermolysis. This means the laser selectively targets the hair while sparing the surrounding skin.

The "secret identifier"? Melanin — the pigment that gives color to both hair and skin.Why is melanin so important?Melanin strongly absorbs light in the 700–1100 nm range. The 808 nm wavelength hits the peak absorption perfectly.

• In hair (especially during the active growth phase — anagen): High concentration of melanin in the shaft and follicle (bulb and bulge).
• In skin: Lower concentration (especially in lighter skin types), evenly distributed in the epidermis.

What happens during a laser pulse?

1. Light penetrates the skin (it's relatively transparent to 808 nm).
2. Melanin in the hair absorbs the energy → converts it to heat (70–100 °C).
3. Heat spreads along the hair and destroys the follicle (growth cells).
4. Skin stays cool — minimal melanin means minimal heating.

Absorption spectrum of melaninGraphs show why 808 nm is optimal:

• High absorption by melanin
• Low absorption by water and hemoglobin (blood)

This minimizes skin and vessel heating.Important nuances

• Dark hair on light skin → Maximum contrast = best selectivity and results.
• Light/blonde/gray hair → Little melanin → laser "doesn't see" the hair well.
• Dark skin → More melanin in epidermis → higher burn risk. Longer wavelengths (e.g., Nd:YAG 1064 nm) or strong cooling are used.
• Modern diode lasers feature powerful skin cooling for extra protection.

In the end, the laser doesn't "think" — it simply follows physics: energy goes where there's more melanin. That's what makes the procedure effective and relatively safe!Ready for smooth, long-lasting results? Romshi — Manufacturer of 808 nm diode stacks