Scientific studies on LED phototherapy



Luminotherapy: medical evidence of its action on the skin

Like any treatment, even if light therapy is particularly gentle, phototherapy has been the subject of scientific studies to determine its effectiveness on a representative sample of the population. Treatment of scars, wrinkles, acne or hair loss… everything has been examined under the microscope by the medical profession.

LED processing: scientific studies and concrete figures

To measure the effectiveness of a treatment, there are not 36 solutions: scientific studies conducted by references in the field on a representative panel of the population must be carried out. This is what has been done with LED treatment on various actions such as rejuvenation, dermatological problems or alopecia to define its success rate. The figures are to be consulted now!

Figures on acne led treatment

Conducted by Dr. Chu, the study on acne led treatment was conducted in the 2000s. If it is not she who made photomodulation known, it is nonetheless a major study in demonstrating the effectiveness of this treatment technique using pulsed light.

Much less invasive than laser treatment, LED treatment uses only the blue and red LEDs to treat mild to moderate acne. It acts in depth to eliminate bacteria and purify the skin while repairing the scars left by pimples. The results of this study are simply amazing.


Study carried out by Dr Chu

It was in the 2000s that Dr. Chu, a British professor, studied the effects of light and more particularly blue and red lights as a treatment for acne.

LED photomodulation is therefore a painless alternative to lasers.

For the treatment of mild to moderately severe acne, LED phototherapy combines blue light (whose benefits in the treatment of acne were highlighted in 2004 in Professor Tzung’s publications) and red light. Blue light acts as an antibacterial by attacking the P. Acnes bacteria involved in acne. This blue light “is not dangerous…”, continues Dr. Fouque “… With its wavelength of 405 to 420 nanometers, it will, without causing skin damage, act on the P. Acnes bacteria that colonizes the sebaceous gland “.

It is associated with red light that penetrates a little deeper into the dermis to ensure better healing and have an anti-inflammatory action.

The experiment consisted of dividing 107 patients with mild to moderate acne into several groups, each corresponding to a different treatment: The first group was exposed to blue light, the second to a combination of blue and red light, the third to white light without heat radiation, while the fourth group was given a specific cream. The distribution of the three light sources is random, and the duration of exposure to these light sources is 12 weeks, at a rate of 15 min per day.

At the end of the treatment, an improvement in 76% of the cases treated was observed, i.e. a three-quarters reduction in the number of blackheads present, particularly with the combination of the two lights (blue and red).

Since then, several studies have validated his early research.

Studies on anti-age led treatment

It is through this study that photomodulation became known. In 2004, Messrs Mac Daniel and Weiss conducted a scientific study on a population sample of 93 people and obtained striking results. They have just demonstrated the action of light therapy on wrinkles, pigment spots and skin elasticity. 92% of the sample tested twice a week obtained more than satisfactory results.

Once this study is revealed to the general public, LED treatment takes a 180-degree turn and establishes itself as a first-rate aesthetic and medical therapy. What is appreciated about her? Its effectiveness and its painless and without side effects.


Study carried out by Mac Daniel et Weiss

The main study is that of Mac Daniel and Weiss in 2004:

  • 93 patients are treated with 590 nm LEDs.
  • With 8 treatments (2 per week) for 6 months, this with clinical and photographic evaluation, patient and operator satisfaction evaluation and 3D photos.
  • The results are as follows: in responding patients, 87% texture improvement, 65% for erythema, 62% for pigment disorders, 56% for peri-ocular fine lines.
  • The degree of improvement is zero for 8%, moderate for 14%, good for 41% excellent for 38%.

Out of 10 randomized patients, there is a 50 to 90% improvement in fine lines in 3D photos.

Study conducted by D. Barolet and Russel at the Skin Optics Laboratory at McGill University in Montreal

Other clinical studies have been carried out in the context of aging.

  • Barolet, in a double-blind study with 660 nm LED on 53 subjects, found an average fine line improvement of 24.6 µm, and in one case 225.5 µm, which proves that there is a great variability in the results, a phenomenon already observed with other remodeling techniques.
  • Russel, in a study on 31 subjects with LED emitting at 633 and 830 nm: in 52%, there was an improvement of 25 to 50%, 81% of subjects showed an improvement in periorbital fine lines.

Data on the treatment led baldness treatment

Jointly conducted by several doctors and scientists, namely Messrs Waiz, Az Saleh, R. Hayani and So Jubory, studies on the effectiveness of LED baldness treatment are no exception to the rule. Here again, the success rate, and this from the first session, is quite impressive, especially since the treatment targeted areas refractory to hair growth.

It is therefore a major advance in the treatment of alopecia, a disease that promotes premature hair loss. The details of the survey are available for further details on the subject as well as the medical opinions of various experts.


Study by M. Waiz, Az Saleh, R. Hayani, So Jubory

Background: Alopecia refers to the acceleration of hair loss in one or more areas, most often on the scalp, affecting both men and women. It is an autoimmune disease that is treated with different techniques, with more or less satisfactory results. Laser treatment of different wavelengths has been used in the treatment of alopecia. Objective: To study the effect of the pulsed infrared laser diode (904 nm) in the treatment of alopecia.

Method: Sixteen patients with 34 resistant areas who had not responded to different alopecia treatment techniques. In patients with multiple zones, one zone was left neutral for comparison. Patients were treated on a 4-session basis, once a week, with a pulsed laser diode (904 nm) at a pulse rate of 40/sec. A photograph of each patient was taken before and after the treatment.

Results: The patients treated were 11 males (68.75%) and 5 females (31.35%). Their ages ranged from 40 to 50 years. Hair growth was observed in 32 areas (94%), while only 2 areas (6%) showed no response. No hair growth was observed in the control areas. In patients who showed results, results were seen in the first week after the first session for 24 zones (75%, while 8 patients (25%) began to show results in the second session.

Conclusion: The pulsed infrared laser diode is an effective technique for the treatment of alopecia with a high success rate on resistant areas of alopecia.

The results on the treatment of stretch marks by led

The erasure of scars by led treatment of stretch marks was also examined under the microscope to determine exactly its scope and effectiveness. It was La Salpêtrière Hospital in Paris that carried out the scientific studies and, once again, we can only welcome the results obtained.

The scrub success rate for recent stretch marks is impressive and the rate of removal of old stretch marks is well over 50%. There is therefore no longer any reason not to choose light therapy to gently treat the exfoliation of dermal scars such as stretch marks.


Study carried out by La Pitié Salpêtrière Hospital

A scientific, clinical and biological study was carried out at the La Pitié Salpêtrière hospital in Paris. It has proven the repairing effect on stretch marks of light from LEDs (Journal of Aesthetic Medicine and Dermatological Surgery n°131 Sept. 2006).

Now, thanks to this dermo-epidermal technique, most people, teenagers, women or men, can expect to have at least 60% of real results on old pearly stretch marks and much more on recent stretch marks. No treatment has ever produced such results. This represents a considerable progress in the treatment of many skin problems.

Study carried out by JP. Tedgui, P. Blanchemaison and C. The Goff

Treatment by led photomodulation with slight to severe stretch marks, in different phases: recent, old and very old. This study, based on the innovative technology of LED phototherapy with a red wavelength of 645 nm to 850 nm, in pulsed mode and continuous infrared on all treated areas, showed a significant overall improvement in the size and quantity of stretch marks.

Significantly, there is an improvement in the appearance of stretch marks, and a consequent gain in skin tone in the treated areas, regardless of the type of stretch marks and skin, but with faster results on more recent stretch marks.

LED phototherapy is a safe, fast and effective technology at the forefront of scientific and therapeutic development. In addition to being totally painless, one of the great advantages of this technology is its safety.


R. Calderhead, Doctor of Medical Sciences

“Recently, Light Emitting Diode (LED) therapy has been studied from all angles for the treatment of non-injured skin, in order to study the photobiochemical cascades that could be involved. As a result of advanced research, these new LED devices increase the repertoire of medical and cosmetic applications. This review discusses the increase in collagen production obtained by photomodulation by addressing the parameters necessary for maximum clinical response.

The applications of LEDs currently being studied at the Tokyo Phototherapy Laboratory and focus in particular on photorejuvenation with mini-invasiveness of the skin and its photobiological bases.”

D. Barolet, A. Boucher – McGill University –  Skin optics laboratory – Montréal (Canada)

[…]Just as the plant uses chlorophyll to convert the sun into tissue support, LEDs trigger intracellular and physiological photobiochemical reactions that activate collagen production in the skin.

We are therefore entering this exciting era, where LED light makes it possible to obtain excellent skin photo rejuvenation treatments. Safer than the sun, this new light therapy helps to reshape photo-aged skin without pain, social eviction or side effects.

Photomodulation indications seen by a dermatologist : Dr François Michel

Its use in medicine and aesthetics began in 2004 but in fact, it is not really a recent tool because it is derived from non-thermal infrared lasers (or soft lasers) widely used since the 1980s for their anti-inflammatory and healing properties, these lasers themselves being derived from so-called infrared lamps used for the same purpose for over 50 years.

These infrared lamps actually emit a combination of colours ranging from blue to nearby infrared, in the same wavelengths as those used with LEDs. In short, this technique is so far behind that the discovery of a late side effect can be ruled out.

LED became famous all of a sudden following a study showing a remodelling and therefore anti-wrinkle effect that its predecessors did not have, because the light is emitted in “pulsed” mode even if one often has the impression of continuous light due to the speed of the frequency of the “flashes”. But be careful not to confuse with flash lamps or pulsed lights that act by heating the skin while the LED does not heat.

This lack of heat is rather disconcerting and yet the effectiveness is real, in three areas: the anti-inflammatory and healing effect, the remodeling effect and the ability to increase the penetration of substances applied to the skin. The mode of action is a regulation of the cell acting on the mitochondria, which are our small intracellular power plants.

As a result, the field of application is extremely wide, ranging from all skin inflammations (or joint inflammations, but that’s another area) to scars or fine lines. A beneficial effect can be added to some pigment problems such as chloasmas or pregnancy masks and studies are also underway for cellulite and hair growth, due to improved vascularization.

And the possibilities are all the more extensive as the LED can be tried on everything because there are no risks. Indeed, apart from the possibility of triggering an epileptic seizure when the pulse frequency is low enough to create painful light pulses, which is in fact rarely necessary, there is no identified medical risk. At the limit, some lamps have pushed the escalation of power so much that they end up heating up a little bit, but we are a thousand miles away from the risk of burning present with each shot of a “hot” laser or flash lamp…[…]

Certainties are the predominant efficacy of red light in the anti-inflammatory and healing effect, the remodeling effect and the increased penetration of substances applied to the skin. The yellow wavelength allows to be more superficial and the infrared near to be deeper, while the vocation of blue light is the treatment of acne. The other established fact is that the LED only gives its potential in “pulsed” mode. And finally, the ultimate certainty is safety. In the end, alone or in combination, the LED is a safe and effective tool.

Doctor François Michel – Collectif VIGIPIL