Alexandrite, diode, Nd:YAG, IPL: which laser suits which skin and hair type?

How the laser types differ

All lasers for hair removal work on the same principle: light is absorbed by the melanin in the hair, converted into heat and damages the hair root. The most important difference is the wavelength. It determines two things:

• How strongly melanin absorbs the light. Shorter wavelengths are absorbed more strongly – good for finer hair, but the melanin in the skin also absorbs more.
• How deep the light penetrates. Longer wavelengths penetrate deeper and are absorbed less by the upper layer of the skin – which is safer for darker skin.

The name of the laser tells you what generates the light: a crystal (alexandrite, Nd:YAG), semiconductors (diode) or – in the case of IPL – not a laser at all, but a flash lamp.

The laser types at a glance

For light blonde, red, grey and white hair, none of the lasers – and not IPL either – is effective, or only to a limited extent, because this hair lacks melanin.

Alexandrite laser (755 nm)

The alexandrite laser generates light at 755 nm in a crystal. This wavelength is absorbed very strongly by melanin and acts close to the surface. That is why it is considered very effective on light skin, including on somewhat finer hair.

The downside follows from the same fact: the melanin in the skin also absorbs a lot of light. On darker skin types and on tanned skin, the risk of burns and pigment changes increases. Many devices with an alexandrite laser therefore also have an Nd:YAG laser for darker skin.

Diode laser (usually 800–810 nm)

The diode laser generates its light with laser diodes. Classically, it works at 800 to 810 nm – slightly deeper than the alexandrite laser and with slightly less absorption in the upper layer of the skin. As a result, it covers more skin types and is considered an all-rounder. Newer diode lasers combine several wavelengths in one handpiece, for example 755, 810 and 1064 nm.

Important for the comparison: a diode laser that works at 755 nm, among other wavelengths, is still not an alexandrite laser. It uses the same wavelength but generates it with diodes. What counts for your result is which wavelength is set for your skin and hair – not how the device is built. More in the article Diode laser: how it works.

Nd:YAG laser (1064 nm)

The Nd:YAG laser works at 1064 nm – the longest of the common wavelengths. The light penetrates deeply and is absorbed least by the melanin in the upper layer of the skin. That makes it the more cautious choice for dark skin types. Because the hair also absorbs the light less strongly, it is less effective on finer hair and is often perceived as more intense.

IPL: not a laser

IPL stands for "Intense Pulsed Light". A flash lamp emits light with a broad spectrum, which is narrowed down with filters. Because what reaches the skin is not a single wavelength but a whole range, IPL can be adjusted less precisely to skin and hair. It can still work – especially on dark hair on light skin. In studios, the expertise requirement under the NiSV applies to IPL too. In detail: IPL vs laser

And what is SHR?

SHR stands for "Super Hair Removal". The term was coined by the laser manufacturer Alma Lasers for a way of working with its diode lasers; it doesn't refer to a separate light source but to a technique: many pulses at lower energy while the handpiece glides over the skin. The heat in the follicle builds up gradually, which most people find more comfortable.

The term is used for diode lasers, but also for IPL devices. So always ask which light source is behind it: "SHR" on its own doesn't tell you whether a laser or a flash lamp is being used.

Which laser is right for me?

A rough guide:

• Light skin, dark hair: All lasers and IPL can work. Alexandrite and diode are considered particularly effective here.
• Medium to olive skin: Diode or Nd:YAG; more caution is needed with the alexandrite laser.
• Dark skin: Nd:YAG or a diode laser with a 1064 nm component, with lower settings and a test patch.
• Fine, dark hair: shorter wavelengths such as 755 nm work better.
• Light, red or grey hair: no laser, no IPL. The alternative is electrolysis (needle epilation).

More important than the type of device is that someone with certified expertise looks at your skin and hair beforehand, treats a test patch and adjusts the settings.

What to expect at MOOD Beauty

We work with a diode laser, the Alma Soprano ICE Platinum. It emits the wavelengths 755, 810 and 1064 nm simultaneously, all three generated by laser diodes – it is neither an alexandrite laser nor an Nd:YAG laser. The treatment is carried out in several gliding passes, with cooling in the handpiece.

The goal is a permanent^¹ reduction: considerably less, finer and lighter hair over a long period.

¹ Permanent hair reduction requires several treatments, depending on the body area and the individual hair and skin type. Success cannot be guaranteed, even when the treatment is carried out professionally. On light, red, grey or white hair, the treatment is ineffective or only partially effective.

FAQ

Sources

1. Vaidya T, Hohman MH, Kumar DD: Laser Hair Removal. StatPearls, NCBI Bookshelf. ncbi.nlm.nih.gov/books/NBK507861
2. Bundesamt für Strahlenschutz: Laser, IPL & Co – Anwendungen optischer Strahlung in der Kosmetik. UMID 1/2016. umweltbundesamt.de/sites/default/files/medien/2218/publikationen/umid_1_2016_bfs_laser.pdf
3. AWMF S2k-Leitlinie „Lasertherapie der Haut“, 2022. register.awmf.org (013-095)
4. Alma Lasers: Soprano ICE Platinum product page. alma-lasers.de

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