Laser hair removal and darker skin: what your phototype changes

Most of the practice’s patients have darker skin, phototypes III to V. For laser hair removal, this is neither an obstacle nor a detail: it is the factor that guides the choice of device, the settings and the timing of sessions. Here is why, without jargon.

What a phototype is

A phototype describes how skin reacts to the sun. The most widely used scale, known as the Fitzpatrick scale, runs from I — very fair skin that always burns and never tans — to VI — black skin that almost never burns. In between, the higher the number, the less the skin burns and the more easily it tans.

Darker skin most often falls between III and V. A phototype is not read from the colour of the day: it is established in consultation, from your untanned skin and how it has reacted to the sun in the past.

Two melanins competing

The laser targets melanin, the pigment that colours the hair: absorbed by the hair, the light turns into heat and reaches the follicle. But the skin also contains melanin, all the more so the darker it is. On fair skin, the dark hair is almost alone in capturing the light; on darker skin, the epidermis absorbs part of it on the way through.

It is this sharing that exposes the skin to burns and pigment marks — lighter or darker than the surrounding skin — when the device or its settings are not suited to it. The whole task is to reach the hair while sparing the skin.

Wavelength matters more than the brand

Each laser emits a specific wavelength, and they do not all travel through the skin in the same way. The 1064 nm Nd:YAG is the reference for olive to dark skin: its light is less absorbed by the melanin in the epidermis, which it spares more. The 755 nm alexandrite is better suited to fair to intermediate skin; the diode laser sits between the two.

The practice works with all three wavelengths, and the choice depends on your phototype and hair, not on a preference for one device. The settings — energy, pulse duration, cooling — matter just as much: a good laser badly set does not protect darker skin.

Why a tan postpones a session

Tanning means making melanin at the surface: tanned skin competes with the hair even more, whatever its starting phototype. Self-tanner does not produce melanin, but it colours the surface of the skin and skews the settings. Hence the rule: no sun, sunbeds or self-tanner for the four weeks before, and a session postponed rather than carried out on tanned skin.

After each session, the same protection applies: SPF 50 on exposed areas for four weeks. Under the Moroccan sun, this often sets the calendar — it is simpler to start in the autumn and continue the sessions through the less sunny months.

Hormonal areas and fine down: caution

On the chin, upper lip, neck or abdomen, hair that appears or thickens may have a hormonal cause, such as polycystic ovary syndrome. The laser acts on the hair and does not correct an imbalance: an assessment may be suggested before starting, and maintenance is more frequent while the cause persists.

Fine down calls for a different precaution. On the face and neck, especially on darker skin, the laser can, rarely, stimulate regrowth instead of reducing it: this is known as paradoxical stimulation. It explains why very fine down is not treated without assessment, and why treatment is paused and reassessed if the hair grows back more densely around the area.

What the laser does not do

Without melanin in the hair, there is no target: white, grey, very light blond or red hairs respond little or not at all, and neither does very fine, light down. It is not a matter of extra sessions or more power: raising the energy would put the skin at risk without reaching the hair.

On dark hair, the aim remains a lasting reduction in the number and thickness of hairs, with no guarantee of permanent hair removal, and maintenance sessions may be useful. The rhythm varies from one area to another — closer together on the face, further apart on the legs or back; the number of sessions, however, cannot be given before the examination.

None of the above replaces the prior consultation: it alone says whether this procedure is right for you, and on what terms.