History The first permanent hair removal technique was electrolysis, which was invented over 100 years ago. It consists of burning the bulb using an electric current. This technique is safe, effective, but extremely slow, which poses a problem for large areas. Pulsed light and laser hair removal techniques are relatively recent, having appeared in the late 1990s. Their success has been growing since then as current machines have been able to benefit from the experience of users and have been improved over the years to increase their efficiency while decreasing their associated side effects. How does it work The hair bulb and the melanin pigments they contain are chromophores, i.e. they absorb light energy.The laser (or IPL lamp) emits a beam of light that passes through the epidermis and is absorbed by the melanin contained in the hair follicle, which is 2 to 4 mm below the skin.Melanin is the pigment that makes up the hair follicle and gives it its colour. When the hair follicle absorbs the light beam, it heats up very strongly. This heat will damage the hair follicle (which is a sort of mini organ made up of a multitude of parts) from the first hair removal session. After a sufficiently repeated exposure (4 to 7 hair removal sessions), the majority of the hair follicles contained in the skin are completely destroyed. Permanent hair removal with laser technology The laser heats the bulbs and destroys them by a thermo-coagulation phenomenon. It is the melanin contained in the bulb that absorbs the laser energy. It works by increasing the temperature of the bulb while avoiding producing the slightest lesion on the skin. This mechanism is also called "selective photo-thermolysis". A laser emits only one wavelength (usually 755 nm, 810 nm or 1,064 nm). Permanent hair removal with pulsed light The pulsed light device emits polychromatic light, i.e. a multitude of visible colours. This light captures the melanin in the hair, the pigment responsible for its colour. The safety of the devices varies from one producer to another and from one filter to another.Photo-depilation methods work best with dark hair on light skin. Dark skin (e.g. due to tanning) can also absorb light energy, causing heat and pain. In this case, the energy level of the device should be reduced and/or infrared wavelengths should be used.Photoepilation methods require regular sessions every 3 to 6 weeks (this interval depends on each individual's hair cycle) for at least one year. Hair should not be pulled out between sessions in order to preserve the bulbs for better elimination when the light is applied. Benefits & disadvantages The role and usefulness of hair is not unanimous among experts. The only known disadvantage of depilation is of an aesthetic nature at the level of the pubis because certain people regret the total definitive depilation of this place a few years after having carried out it.As for the advantages, there are many, including the time saved by no longer having to undergo weekly hair removal, the reduction in stress and pain caused by waxing and the aesthetic beauty of having a smooth body.In contrast to waxing or electrolysis, permanent hair removal does not generate ingrown hairs: when the hair grows diagonally under the skin, causing tissue inflammation and pain. Differences between laser and pulsed light Pulsed light benefits Technics which had be proven to be efficient, and known by almost everybody Cheap devices Technique easy to learn and accessible to all beauticians Disadvantages of pulsed light Sessions hurt, especially around the bikini zone Side effects are much more unpredictable than laser diode, with 14% to 33% of treatments having side effects other than redness (which occurs in 80% of cases), according to studies. The efficiency is lower than laser devices. 1 2 3 4 5 6 7 There is a rebound effect where the hairs grow back thicker than before a cure. 7 2 Does not work well on blond hair 8 Benefits of Laser permanent hair removal Very efficient technique and more effective than IPL 9 10 11 12 13 14 15 16 Effective on blond hair Treats all skin types, even dark and black skin.16 17 18 19 20 21 Painless technique and less painful than IPL (ideal for bikini waxing) 22 Safe technique with almost no side effects (scanning technique) 20 21 23 24 25 Disadvantages of laser permanent hair removal Requires quality training More expensive technology than pulsed light, which makes the devices more expensive. Pulsed light efficiency (IPL) Studies on the efficacy of pulsed light have shown relatively satisfactory results: After two sessions, a reduction of 10% to 39.16% of hair can be expected. 13 16 After three sessions spaced 6 weeks apart, three different studies showed a reduction of 46.4%, 50% and 74.53% of the hair on the treated areas.11 26 22 After 5 sessions, one study found a reduction of 50.4% and 77%, observed 6 to 9 months after the end of treatments. 19 27 After 6 sessions, one study showed a reduction of 52.7%, measured after 12 months, 10 The results, whose percentages of effectiveness are sometimes significantly different, can be attributed to the fact that the machines and techniques used between studies differ, as IPL technology has evolved considerably since its beginnings around the 2000s. The new scanning IPL machines are more efficient and less painful than 10 years ago. Effectiveness of laser hair removal After 2 sessions, a 40% reduction in hair can be expected.16 After 3 sessions, a reduction of 58.4%, 67.6% to 75% of the hair can be expected. 28 25 11 After 4 sessions, a hair reduction of 87% can be achieved. 29 After 6 sessions, laser hair removal will be optimally effective on large pigmented hairs on which a reduction of between 69% and 90% of the hair will be obtained. 10 30 31 On black and dark skins, efficiency is reached after more sessions because the energy delivered must be lower. In these cases, after 6 sessions, the hair reduction is 52.87% (upper lip) and 73.81% (chin). 17 21 he effectiveness of permanent hair removal also depends on these factors: lhe anatomical location and texture of the hair: the armpits are generally easier to treat than the upper lip. the gender of the client: women need fewer sessions than men, other things being equal. Hair type: black hair is easier to treat than blond hair. Hair density: sparse hair density is easier to treat than very dense areas. ecipient satisfaction Satisfaction with the treatments is very high, many users are delighted that they no longer have to constantly worry about their hair growing back. Many describe the results as having a liberating effect that saves a lot of free time and money, in addition to the aesthetic effect that is highly appreciated by the beneficiaries and their partners. How many sessions are needed? For the bikini, arms, legs and back it takes 4 to 8 sessions, depending on the person.For the armpits, the time is a little shorter: it takes 3 to 6 sessions.The number of sessions varies according to the type of skin, hair and hairiness of the treated individual. Individuals with little hair and/or with coarse hair will need fewer sessions than the opposite case, i.e. high hairiness or very fine hair.Darker and blacker skins generally need more sessions (because the energy used is lower).Between sessions, you can depilate or shave (even right after the session) but the ideal is to let it grow back until the next appointment for maximum efficiency.The bulbs destroyed are destroyed forever, the sessions can even be spaced 3 months apart if the budget does not allow one session per month ... the results will just take longer to become visible but the final result will be the same. What is the recommended interval between sessions ? Respect a minimum time between two consecutive sessions of : hree to six weeks for face, bikini line and underarms. Four to eight weeks for legs, arms, back, torso. For annual maintenance sessions: wait for hair to grow back a minimum. There is no significant decrease in efficiency if the maximum waiting time is forgotten and exceeded. How does a session go? Video of a permanent hair removal session. Precautions before the session. For a more effective and safe treatment, sun exposure is prohibited in the 4 weeks preceding the laser session. Therefore, protect the area to be treated with a high protection sun block.Preparation of the skin at home before the session The skin must be cleansed beforehand with water and a mild cleanser. No traces of make-up or deodorant should remain on the areas to be treated.. The hair should be shaved at best 2 to 3 days before the session or otherwise on the same day. Avoid shaving fine hairs. Don't shave the face (for women), in that case it's better to cut the black hair with scissors.. Failure to shave, depilate with depilatory cream 3 days before treatment. During the session The client lies back and relaxes. Many women even fall asleep, because permanent laser hair removal by scanning generates only a slight feeling of warmth, which is very pleasant. Precaution after the session During the week following the session, a "regrowth" may appear other than the hair detached from its follicle, which naturally emerges from the hair shaft before falling out.. etween sessions, it is essential not to proceed to a "mechanical" removal (tweezers, wax, electrolysis, electric depilator) which would disrupt the hair cycle. If you wish, you can shave or use a depilatory cream. Untreated hair can be destroyed in subsequent sessions.. 10 to 20% of the hair falls out in the following days but also already during the session. As long as post-treatment irritation persists, the skin should be protected with a sunscreen and sun exposure should be avoided as this may induce abnormal pigmentation. cheduling a sun vacation two weeks after a session is strongly discouraged. Can permanent hair removal be performed on areas of the skin containing beauty spots? As long as moles are not dubious and problematic, the medical literature does not report any contraindications to treating the skin if it has moles.On the contrary, pulsed light or laser diode sessions seem to attenuate moles by destroying melanocytes and melanin deposits.In case of suspicious lesions or spots, it is always recommended not to treat immediately and to seek advice from a dermatologist before performing a session. Is permanent hair removal effective on fine hair, down and white hairs? Pulsed light and laser are not very effective on white hair and very fine down, which is usually lighter than the skin colour. However, laser hair removal is effective on blond hair because it contains melanin; the lighter the skin colour and the darker and thicker the hair, the faster it works. On the other hand, the more hair you have, the longer it lasts because there is a larger working area. Blond or red hairs, unfortunately, this will not be conclusive. What are the risks and side effects after treatment? In general, laser depilation by scanning (new technique), whose parameters have been well chosen, does not involve any risk of burning.Pulsed light on the other hand (depending on the machine used) carries a greater risk of unpredictable burns because the wavelengths emitted are absorbed by the epidermis as much as by the bulbs. Burn caused by a pulsed light session Post-intervention inconveniences On dense hair areas, redness (erythema) is accompanied by a sensation of warmth comparable to a sunburn. These effects last one to two days maximum. Allergic reactions are very rare, may appear as small red spots caused by allergy to light. In case of tickling or tingling after the treatments apply an anti-inflammatory cream (Trihistalex type). However, sun allergy is not a contraindication for treatment. Long Term Risks The medical literature does not list any cases of long-term side effects for permanent hair removal by laser and pulsed light.Apart from the rare inconveniences that may appear after a session, there is no impact on health or on the skin. On the contrary, two studies suggest that the laser diode stimulates the natural production of collagen and could therefore be used for anti-aging purposes. When is it necessary to shave before a session? It is important to shave the areas that are going to be permanently depilated because the hairs get very hot during the procedure. If they protrude over the body, their high heat will disturb the client during the session. In case you forget, there is no major inconvenience to shave just before the treatment. For the face, it is recommended to cut the hair with scissors rather than shaving. The ideal is to shave two days before the final hair removal session. How long is a session? Depending on the size of the area to be treated, it usually takes about an hour to treat a full back or two full legs. Full arms, face or bikini usually take half an hour.Does permanent hair removal hurt?Permanent hair removal with pulsed light heats the skin very strongly and can cause some discomfort/pain (especially in the bikini area). A laser-type device heats the skin much less (barely noticeable during treatment), especially if it is equipped with a cooling system at its tip, which is the case with the best models. Contraindications Taking tanning activators such as Oenobiol or the application of self-tanning creams 2 weeks before the session. The application of essential oils anywhere on the body one week before the session. The application of bleaching/depigmenting creams 2 weeks before a session. Electric depilation or waxing on the areas to be treated 4 weeks before the session. Exposure to the sun two weeks before or after a permanent hair removal session Being or actively seeking to be in a girdle Skin diseases such as Vitiligo (skin depigmentation), psoriasis, skin cancer, eczema or dermatitis Taking roaccutane or Vitamin A derivatives such as isotretinoid Being being treated with photo-sensitizing drugs (they can cause burns and side effects). List of photo-sensitizing drugs here . What are the areas to avoid and the prohibited areas? Hair removal can be done on all areas of the body except for these two areas: Directly on the genital areas in men or women: there are not yet enough studies demonstrating the total safety of these procedures. For laser hair removal: it is not recommended to treat eyebrows because they are too close to the eyes. Tattooed areas What degree is needed to practice permanent hair removal? Until today, the law governing the aesthetic practice did not authorize permanent hair removal for beauticians and reserves this practice to doctors. Indeed, Article 25° of the decree of January 6, 1962 mentions: Entering the medical monopoly "Any mode of depilation, except depilation with tweezers or wax".