Diode vs IPL vs Nd:YAG: Laser Hair Removal Types Compared

Every hair removal laser and IPL device relies on the same idea, called selective photothermolysis. Light of a chosen wavelength passes into the skin and is absorbed by melanin, the dark pigment in the hair shaft and bulb. The absorbed light turns into heat, which damages the follicle's ability to grow a new hair.

Because skin also contains melanin, the challenge is to heat the hair without overheating the skin around it. That balance is what separates the device types. Each wavelength is absorbed by melanin to a different degree and reaches a different depth, so each suits a different combination of skin tone and hair colour.

Only hairs in the active growth phase have a pigmented bulb attached, so only those respond at each session. That is why every device needs a course of sessions several weeks apart, and why no device clears hair in one visit.

These are the device families you are likely to see named by clinics. Wavelengths are given in nanometres (nm).

Diode lasers are among the most widely used hair removal devices in Singapore and Malaysia. Their wavelength sits between alexandrite and Nd:YAG, absorbed well enough by hair pigment to treat medium and fine dark hair, while reaching deep enough and sparing enough of the skin's pigment to be used on a range of Asian skin tones.

Many modern diode devices cool the skin through the handpiece and treat in quick, repeated passes, which helps comfort. Some combine diode with other wavelengths in one handpiece. The name on the machine matters less than whether the settings are adjusted for your skin and hair.

The Nd:YAG laser has the longest wavelength of the common options. It is absorbed less by the pigment in the skin's surface, which makes it a frequent choice for darker skin tones, where the risk of burns and pigment changes is otherwise higher.

The trade-off is that it is also absorbed less by hair pigment, so it tends to work less well on fine or lighter hair and can feel more uncomfortable. It suits deep, coarse hair such as the beard area, underarms and bikini line in people with darker skin.

IPL devices use a flash lamp that releases a broad spectrum of light, filtered to remove the shortest wavelengths. Because the energy is spread across many wavelengths, it is less precisely targeted at hair pigment than a single-wavelength laser.

IPL can reduce hair, particularly dark hair on light skin, and the same device is often used for sun spots and redness. It is generally less suited to darker skin. Home IPL devices work on the same principle at much lower power, so results are usually slower and less complete than with clinic treatment.

Two things decide which device suits you: how dark your skin is and how dark your hair is. Dark hair on light skin is the easiest combination for every device. As skin gets darker, longer wavelengths and careful settings become more important. As hair gets lighter or finer, results get slower with every device.

Recent tanning matters too. Tanned skin holds more pigment, which raises the risk of burns and patchy darkening, so treatment may be delayed or settings reduced. In Singapore's year-round sun, consistent sun protection on treated areas is part of a safe plan.

Grey, white, blonde and many red hairs have too little melanin for any laser or IPL device to target reliably. For these, electrolysis, which treats each follicle with a fine probe, is the usual alternative.

Clinics often lead with a device name. These questions tell you more than the brand does.