Hair reduction treatment with High Intensity Pulsed Light (HIPL)* with GEM** technology

Dr. E. H. Nuriel – Neutrino



Active optical systems GmbH encapsulate more than 25 years of experience in the hair removal field. In the year of 2000 the first device based on light energy was introduced to the market. Since then many improvements were devised and installed and today the company manufacturers the Crystal 512 and the Record 618, hair removal machines. The machines are based on Active’s GEM (Geometrical Energy Management) patented technology. The present research is intended to test this technology and its implementation in two major fields: effectiveness of treatments and the potential treatment side effects.

The research was performed on 2992 patients in different ages, genders, skin and hair colors in order to achieve an accurate picture on the entire population. The research was performed over three years, in 73 different locations, and according to our knowledge this research is one of the largest of its kind, made in this field.

The results show the abilities of the HIPL\GEM technology in both fields.



Investigations (Anderson et Al)[4] has clearly demonstrated that a flash of high intensity light penetrates through the epidermis, absorbed and assimilated in the hair bulbous region and acts as an inhibitor to the hair follicle through temporarily temperature rise and agglutination.

The follicle has several parts of interest:

Dermal papilla  - The dermal papilla directs and dictates the embryonic generation of a hair follicle and retains this instructive ability throughout the life of the hair follicle. It consists of a highly active group of cells shown to be capable of inducing follicle development from the epidermis and the production of hair fiber.

The bigger the Dermal Papilla, the more cells it has - the thicker the hair fiber that the hair follicle produces.

Basement Lamina The Basement Lamina is a thin layer of cells that separates the Dermal Papilla form the hair sheath cells. Providing a barrier between the dermis and the epidermis.

Matrix cells  - The Matrix cells are Epidermal derived cells close to the Dermal Papilla. These cells remain undifferentiated and focus on multiplying and proliferating to produce more cells. Those cells are located in the center of the hair follicle and designated to become part of the hair fiber. Their name is Cortex (cortical) cells.

Cortex Cells – the Cortex cells are made by the matrix cells, aimed to become a part of the hair fiber.

As these cells multiply, the constant stream of production pushes the cells upward towards the skin surface. As they move upwards they begin to differentiate into particular cell types. The cortex cells change from a round into a flattened appearance. They are squeezed together into layers (lamella). If the hair follicle contains melanocyte cells the melanin pigment is incorporated into the cortex cells. These cortex cells become keratinized and hardens. As they do so it becomes impossible for the cells to function properly and the cells die. The keratinized cells are then pushed away from the hair bulb region upwards, as the new cells develop underneath. The cortex cells are now part of the dead keratinized fiber. This is the hair we see.

Capillaries – small blood vessels that brings nutrition and oxygen via the blood stream to the hair follicles and takes away the CO2 and the waste produced in the cell’s metabolic cycle.

When we give a pulse of light, the light penetrates the epidermis and absorbed in the cells.

The darker the area the more energy it will absorb. As it can be seen from Fig.1, the darkest area, is the area of the matrix cells (the cells that produce the hair fiber cells), that had melanin inside the cells.




Figure 1: The construction of the hair bulbous

 Another dark area is the Capillaries area – especially the capillaries that have vain blood in them. Vain blood is darker because it has deoxyhemoglobin, which is not attached to oxygen. 

When we give a pulse of light many matrix cells are coagulated and stop functioning.

Matrix cells, which are not coagulated, are triggered to activate their calcium pumps. According to Friedmann (1993)[19], a high intensity light pulse will cause a vast calcium release from mitochondria into cytoplasm. The hyperactivity of Ca­­­+2 pumps exhausts the ATP (Adenosine Tri-Phosphate - an energy molecule) pool, denies it form the cells, thereby inhibiting cell metabolism resulting in the production of less Cortex Cells and therefor – less hair or more feathery hair and less terminal hair.

Another effect of the HIPL\GEM is the clotting of the vain blood in the capillaries. The clotting disturbs the blood supply to the hair follicle meaning less food and oxygen are delivered to the hair follicle, resulting in a smaller ability to produce hair.

These three effects cause hair reduction and removal. The coagulation is the main reason but the other two effects contribute to the hair loss as well.

Active Optical System’s aim is to achieve 80% hair growth reduction –according to the FDA definition.

90 % of hair growth sites are in the region of 3 mm under skin surface, most of them imbedded in the dermis.  With the HIPL\GEM technology we focus the energy on the hair grow sites.

In order to have effective hair reduction and removal significant energies must be applied to the skin. Two antagonist factors must be taken in consideration for successful result: each follicle must be damaged, but the surrounding tissue, especially the epidermis must be protected from damage. Using long wavelength (1100 nm), are much more suitable for deep hair reduction because of reduced scattering in the dermis, and greater penetration depth [5]. The use of broadband light spectrum, gives the advantage of “energizing” the hair follicles [7]. This technique is very effective for hair reduction, as it operates on all the types of hair (not white), and supplies the needed energy to diminish it. The melanin can be effectively targeted by the intense light source throughout the visible light spectrum [4].

Hair growth is a cycle with four stages. The best time to target a follicle is when it is at the first hair growth phasethe Anagen phase. In this phase we will find the largest concentration of melanin and blood supply, which means that in this phase we find the biggest color differentiation between the follicle and its surrounding tissues.

Targeting the follicle at this phase provides us with the best conditions to destroy the hair follicle.

If we fail to destroy the follicle at this phase, the follicle will continue the hair growth cycle and eventually return once more to the Anagen stage according to its natural cycle. The duration of each phase changes according to the anatomical location and varies between several weeks to several months.   

When we apply energy to the skin, the principle of Photothermolysis and the thermal relaxation time should be considered [4,5]. The term of thermal relaxation time is used to determine the limitation of the thermal damage when a designated target absorbs the energy of a given wavelength in a specified period of time. With the right combination of wavelength, duration and energy, it is possible to target a hair follicle without causing any injury to the surrounding tissue. Taking in consideration all the factors mentioned above, we found, that if the light source delivers its energy through a large beam (greater area), short duration (concentrated energy), high intensity (better penetration) and low repetition rate (larger time to cool), an increase of penetration and follicle destruction occurs [16, 17, 18].

This enhances the chance of affecting large area of growth centers, and a greater chance of hair follicle destruction. Moreover, in order to protect the epidermal melanin from damage, a water based cooling gel is applied on the skin surface.

In this research we investigated the abilities of the HIPL\GEM technology and its implementation in Active’s machines to achieve permanent hair reduction without significant unwanted side effects.


Materials and Methods

In order to conduct this research we used two kind of machines: Crystal 512 (commercial-lamp lifetime 100.000 pulses) and Record 618 (industrial-lamp lifetime 200.000 pulses), all other specifications are identical. Both machines practice the HIPL\GEM technology.

The machines are approved by governmental CFS and withstand the medical safety standard IEC 60601-1, IEC 601-1-2 and the CSA standard for Canada and the US. The machines use a technology that manages to concentrate the bulk of the energy to a precise geometric plane, positioned on the selected target (hair follicles, pigmentation, vascular lesions, acne, herpes, skin rejuvenation etc.

Both machines have a broadband wavelength from 420nm up to 1100nm. Large spot size 15x50mm, pulse repetition rate is of 3 to 4 Seconds. The maximum energy, which can be delivered, is 22 J/cm2.

Twelve fully automated computerized programs, intended for most skin types and hair colors, designate the fluency of each pulse (J/cm2).

Due to the targeting, no excessive heat “overloads” the adjacent tissue, this makes the treatment efficient and painless.

The research was conducted on a population who has a high diversity of skin colors. The diversity of skin colors allows us to get a representing picture of the world population from which we can implement on the whole world population. 

Tanned skin allows us to use less energy since it will absorb energy just like the follicle’s melanin. Due to smaller color differentiation selective photothermolysis is harder to achieve. The meaning is that if the machines perform well on tanned skin they will perform well and even better on brighter skin. 

The research was conducted on 2992 patients in order to supply the research team with reliable results that can give a good indication on the machine’s performance.

The research was conducted in 73 different clinics for three years in order to check the performance of the machines compared with the FDA definitions of hair removal and hair reduction.

The aim was to check if the machines could reach 80% of permanent hair reduction without significant side effects.

During the research each patient was treated according to the manufacturer’s guidelines and protocol. All treatments and patients where monitored and treatment specifications and results where collected.

The treatment intervals and energy where adjusted specifically for each patient, considering skin color, treatment area, hair type. The sensitivity of each new patient was checked to determine the optimal computerized program to be used.

In cases, where the site to be treated is covered with dense hair, pre-shaving was done, to prevent energy absorption by the hair on top of the skin and allow clear way to the hair follicle

Experience and professional judgment were used to determine the ideal treatment parameters for each patient, this was determined by delivering several test pulses at an inconspicuous site, with equivalent pigmentation, starting at low energy fluency and slowly increasing the energy fluency. Undesirable effects, such as pain, itching, redness, transient erythema, edema, whitening and blistering were to be avoided. Only after the program to be used, is defined for each new patient, the actual treatment at the pre determined sites begin.



As mentioned before, 2992 patients were treated with the machines. Each patient was treated with a preset computerized program, appropriate for his skin color, type of hair, the treated area, the hair color, the patient sensitivity etc.

The treatments were preformed on a variety of the body locations except the eyes, the nipples and other sensitive location according to the patient sensitivity.

The fluency used was designated according to many factors, but the main factors taken in consideration were the skin color and the hair color.

The patients received a total of 27763 treatments with the average of 9.3 treatment for each patient.

We can clearly see from Fig.2 that 77.17% (2309 patients – see Fig.3) of the treated patients reached at least 80% of permanent hair reduction. These patients received more than 10 treatments per patient.

9.19% (275 – see Fig.3) patients reached at least 70% of permanent hair reduction – see Fig.2.

Only twenty one patients (see Fig.4) developed mild side effects (0.702% - see Fig.5) which is completely negligible, 16 patients had mild erythema, 3 patients had mild swelling with extremely mild edema, 2 patients felt itching, all the symptoms disappeared within 24 – 48 hours post treatment.

All results were evaluated after completing the treatment session. The first two treatments were done two weeks apart from each other. Each time the treatment was evaluated. The treatments continued with intervals according to the patient’s hair growth cycle timing - until the patient was satisfied according to the promised expectations.


Hypertrichosis, facial, or other, may result in more than a cosmetic problem for females. It may lead to severe psychosocial stress. Transsexuals, males to females are especially burdened because of the massive hormone therapy.

Hair removal by shaving, mechanical depilation, waxing and chemical blanching proved to be unsatisfactory and sometime may bear a considerable risk when chemical blanching agents are used. However, better or longer lasting therapeutic effect has been observed after electrolysis, thermolysis or joint treatment (blend), these methods are time consuming, not efficient, painful, uncomfortable. Some researchers described surgical approach methods, which carries a considerable risk of scaring.

Recently high intensity, pulsed, coherent and non-coherent light methods were suggested, and proved to be an effective (less time consuming) and satisfactory (fulfilling promised results) in hypertrichosis treatments [1, 2, 3]. Selective photothermolytic treatments, not only damages the pigmented follicular cells. The vessels that provide nutrition to the follicle are also damaged by photothermolytic coagulation. The coagulation usually leads to complete follicle atrophy.

Flash lamp device emitting an intense pulsed non-laser light, with a broadband spectrum, (420-1100nm) has, due to the wide wavelength diversity, the ability to treat, as well, vascular and pigmented lesions and other skin disorder.

Hair reduction, with an intense pulsed non-laser light, applying a broadband wavelength visible light spectrum, (420-1100nm) emitted from a flash lamp device, has a wide wavelength diversity, it can also be used to treat vascular and pigmented lesions and other skin disorder.

Cooling time between pulses, is set automatically when choosing the program. When the proper program is chosen, the follicular temperature at the targeted area rise above its destruction threshold, while surrounding tissue temperature remains low enough to avoid any skin damage.

The light emitted from the machine is delivered through a special crystal light guide. The light guide is coupled to the skin with a transparent cooling gel to protect the epidermis from excessive heating.

From the above results, we can clearly see that the combination of the HIPL\GEM technology implemented in Active’s machines can provide the expected results set by the producer.

The potential of the flash-lamp technology, and the potential for diversity in application, is a great advantage to the system. Practically the machine proved to be worthwhile for pigmented blemished skin, vascular lesions, skin rejuvenation, Acne Vulgaris and Herpes Simplex [13, 14, 15].

The results of these study points shows that Active’s HIPL\GEM machines are safe and effective for hair growth reduction. Hair re-growth seems to be leveling off and remained stable for the duration of our follow up, which sums up to 36 months. This suggests that a portion of the hair follicles had sustained an injury, which prevented them to resume their full activity and ability to grow hair, at least for the observation period, and logically, for other periods to come.

Histologic studies, done by Dieric et al, suggests, that long term clinical hair reduction, results from the miniaturization of terminal hair follicles to vellus-type hair follicles and degeneration of hair follicles, with or without fibrotic remnant [12]. The latter accounts for the true reduction in the number of follicles.

Negligible mild side effects that occurred during the treatments usually completely disappeared within a short time.

This current study represents the large cohort of subjects (2992) prospectively followed by long term observation. The considerable length of follow up time, in substantial number of subjects, supports the claims for safety and effective usage of HIPL\GEM apparatus for permanent hair reduction. 




The computerized programs, the algorithms designed for the HIPL\GEM machines and the usage of wide spectrum of intense light proved to be a very effective technique for long-term hair reduction.

Furthermore, the extreme minor side effects recorded (which completely disappeared after a short while) and the high percentage of successful treatments on many patients, demonstrates clearly the efficiency and safety of this method.





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