How permanent laser hair removal works

How does laser hair removal work?

Laser hair removal is a permanent hair removal technique. Equipped with Alexandrite and ND:YAG technologies, laser hair removal is effective on all skin types.

Backed by twenty years’ experience, our Epilium & Skin center, a specialist in laser hair removal in Paris, guarantees you quality services, delivered by a qualified team and using the latest-generation lasers.


Laser hair removal works by emitting a beam of light that passes through the epidermis along the hair until it reaches the bulb, responsible for hair regrowth.

It’s the melanin in the hair that absorbs all the laser energy, transforms it into heat and transmits it to the hair bulb by conduction. This heat input permanently destroys the structures responsible for hair production and growth.

The wavelength used to destroy the hair is chosen so as to target only the melanin: this is selective photothermolysis, destroying only the hair structure without affecting adjacent areas.

Once the bulb has been destroyed, hair regrowth is virtually impossible, resulting in a permanent result. Permanent hair removal destroys 80% to 95% of the hair present at the time of treatment (results vary according to age and area treated).

Laser treatment is not effective on very light, white or red hairs that contain little or no melanin.

Note, however, that in 10% of cases, treatment does not work, even in patients with a good indication for treatment. These people have what is known as “non-receptive” melanin. We can detect this after the third session, during the first treatment assessment.

Permanent laser hair removal is therefore a complex and variable process, which is why it’s a good idea to make an appointment for a free initial consultation so that the doctor can make a personalized diagnosis. During this consultation, he will be able to assess the number of sessions required.


Suitable for all skin types,permanent laser hair removal is now also available for black and dark skins. Hair removal from dark skin is made possible by the latest generation of lasers used by Epilium & Skin hair removal centers.

Until recently, darker skins could not benefit from this new practice, as Alexandrite-type lasers, by acting on the melanin contained in the skin, caused skin burns. Dark skins concentrate much more melanin in all layers of the epidermis, and conventional lasers cannot distinguish between melanin in the hair and melanin in the skin.

But thanks to the latest generation of lasers, laser treatments are no longer reserved exclusively for white skin, and can now be adapted to all phototypes, and in particular to mature and black skin.


    The Alexandrite bar, a semi-precious stone, produces a red light (wavelength) that is well absorbed by melanin.
    This laser is used when the hair is black or dark and the skin is fair. The wavelength ensures deep penetration of the light beam without the need for high fluence.
    It guarantees efficiency, comfort and safety unmatched by other laser families.
  • ND:YAG – 1064 NM
    Its wavelength is poorly absorbed by melanin, ensuring deep penetration of the light beam. This is the laser for hair removal from dark and black skin. The laser beam not only localizes the melanin contained in the hair, but also acts on the hemoglobin contained in the blood vessels. As a result, this laser can only be used on dark to black skins, which are highly concentrated in melanin, with no risk of burning.

Hair removal lasers from Epilium & Skin centers are classified as category IV and must be used under medical supervision. We offer Cynosure, Sériderm and Candela laser machines, to guarantee optimal treatment in complete safety.

Any use of medical lasers must be subject to regulatory precautions (special eyewear, cooling system, etc.).


The length of the laser hair removal treatment depends on the hair cycle of the area to be treated (7 to 18 months depending on the area) and the phototype of each patient.

Depending on the area to be treated, 4 to 12 sessions are required, spread over the entire hair cycle. The number of sessions varies according to the area to be treated.

For example, underarms, bikini line and half-legs require fewer sessions than the lower face, thighs and back.

A precise estimate will be provided during your first free consultation.

  • For laser hair removal on the face, it is generally advisable to come at the time of hair regrowth, i.e. 4 to 5 weeks after a session. It’s perfectly possible to interrupt the sessions during the summer or when you’re tanning.
  • For body laser hair removal, it is imperative to allow at least 8 to 12 weeks between sessions. If these intervals are not respected, you run the risk of doing more sessions than originally planned.

During the treatment, you can use a razor and depilatory cream to remove any regrowth, but under no circumstances should you remove hair with wax, tweezers or an electric epilator.


Free consultation

Permanent laser hair removal must begin with an initial consultation. At Epilium & Skin, this first appointment is free of charge.

This interview is an opportunity to discuss any contraindications and precautions to be taken with the practitioner, as well as to find out about the progress and feasibility of your treatment.

Our practitioners are here to listen to you: they carry out a clinical examination and analyze any allergies you may have, your skin history, current treatments, the condition and nature of your skin, your hair type and your most recent exposure to the sun.

Secondly, our specialist will draw up an assessment of your hair growth and check, by means of a questionnaire, that there are no contraindications to your medicalized permanent hair removal. He must assess the feasibility of your treatment in order to establish with you a reasonable program in terms of results and effectiveness.

Following this consultation, the doctor will be able to determine the most suitable laser for your phototype, the recommended parameters and the estimated number of sessions.

The number of laser hair removal sessions varies according to the area to be treated, but above all, it’s unique to each patient.

A laser hair removal test will be carried out on the areas you wish to treat, and the doctor will answer all your questions before giving you a quote, an informed consent form and an information sheet. This will give you time to make an informed decision.

Treatment appointments

At the start of each session, the doctor will examine your skin and hair growth. He will check that there are no contraindications to the treatment.

Before the session begins, the laserist will fit you with protective eyewear to shield your eyes from the light energy released by the laser.

Permanent laser hair removal can be slightly painful. This pain, although quite bearable, can be reduced by using an anaesthetic cream a few hours before the session. This cream should be applied to shaved skin.

  • The area to be treated is marked out with a white pencil.
  • Once the laser has been set up, the session can begin.
  • The laser beam scans the area to be treated.
  • At the end of the session, a soothing cream is applied.

By the second session, you’ll notice that your hair is finer and sparser.