Which laser is best for hair removal

A flash of light passes through the skin and is absorbed by the pigment in the hair, melanin. The hair heats up and passes the heat to the follicle it grows from. The follicle weakens, and the next hair comes out thinner, sparser or not at all. Everything else that sets the machines apart comes down to one question: how to give more heat to the hair and less to the skin.

The key parameter is the wavelength. The shorter it is, the more strongly melanin absorbs it, which means the hair but also the skin around it. The longer it is, the deeper the beam goes and the less it touches the skin. That is where the whole difference between laser types comes from.

Sources: StatPearls (NCBI), 2023

The shortest of the working wavelengths, and that is its strength. Melanin absorbs it eagerly, so alexandrite handles fine and light-brown hair that other lasers stall on. On fair skin it is often the fastest route to a result.

The flip side is the same thing: pigmented skin absorbs 755 nm too. On darker or freshly tanned skin the risk of burns and marks goes up, so the power has to come down, and the effect drops with it. Summer is strictest with alexandrite. And without good cooling it feels noticeably hot.

Sources: American Academy of Dermatology

A longer beam that goes deeper and touches the skin less. A diode works calmly on darker and tanned skin, handles thick dark hair on legs, underarms and bikini well, and is usually the more comfortable of the two. It is the most common type in salons, and not by accident.

Its weak spot: fine and light hair. There is little melanin in it, the long wavelength has nothing to grab, and the last hairs on arms, the face or the stomach are sometimes left behind. Then the course drags on and the result hits a ceiling.

The longest of the working wavelengths. Skin pigment barely absorbs it, which is why the neodymium (Nd:YAG) laser is considered the safest for darker and dark skin, up to skin types V and VI, and copes more calmly with a fresh tan. The beam goes deeper than the others and reaches follicles that sit low: thick dark hair in the bikini area, on the legs and on men's backs.

The flip side: the hair absorbs this wavelength less strongly too. To heat the follicle you need more power, and the flash feels hotter. On fine and light hair the neodymium laser does not work: there is too little pigment in it. So as the only laser it does not suit everyone, and in a hybrid it becomes the third range, the one for dark skin.

Sources: Skin of Color Society, StatPearls (NCBI), 2023

A hybrid, or broadband, laser does not emit one wavelength but a whole range at once: it has an alexandrite, a diode and a neodymium part, from 755 to 1064 nm. One flash works on fine hair on fair skin, on thick hair on darker skin and on dark skin, where an alexandrite is dangerous. You do not have to guess in advance which machine will suit you, and you do not have to change salons halfway through a course when the hair has become finer.

There is a downside too: universal does not mean the strongest at every point. In the ideal case for alexandrite, fair skin and fine hair, a single-wavelength laser at its peak can give a little more per session. A hybrid wins differently: it works just as confidently on different skin and hair types and does not lose ground when the skin has darkened over the summer.

We work with a hybrid laser with alexandrite, diode and neodymium ranges. We chose it after working on different systems: people with very different skin come to us, and keeping a separate machine for each is convenient for nobody, neither us nor the client.

We saw two main advantages! First: contact cooling. The tip cools the skin at the moment of the flash, so even bikini and underarms are taken calmly and sensitive skin does not stay red for long. Second: we work without gel. No cold slippery mass on the skin, no smears on clothes, the tip sits flush against the skin, and it is cleaner from a hygiene point of view too: after every client the tip is disinfected and the single-use materials are replaced.

People regularly come to us after a course in another salon: 8-10 sessions on an alexandrite or a diode, and the hair on the stomach, arms or upper lip is still there. On the hybrid these stubborn patches often go within a few sessions, because the flash catches the hair a single-wavelength laser could not.

It has happened the other way round too. For a few clients our laser stopped giving the maximum effect on the last sessions, and we said so plainly: they finished the last one or two sessions on an alexandrite laser and closed the course. We consider that normal. Everyone's hair and skin are different, and the specialist's job is to say in time that it is time to change the machine, not to stretch the course for the revenue.

Ask what wavelength the machine has and whether it suits your skin and hair type. Ask whether it has contact cooling. And look at the hygiene: single-use materials, the tip disinfected after every client. The result depends on the machine, on the specialist and on whether the session lands in the hair's growth phase.