Low-Level Laser Therapy (LLLT) Clinical Study
A Basic Science Investigation Designed to Elucidate the Mechanism of Action,
at the Cellular Level, for Red Laser Light Therapy and Hair Growth
The physiological effects of Low-Level Laser Therapy (LLLT) on human follicular cells surrounding dermal tissue structures.
This study on LLLT aimed to define the safety and physiologic effects that occur when the human hair follicle and surrounding tissue structures are exposed to this type of radiation. The data available has been the result of testing murine models, not human. To properly identify the effects in human subjects, exposure to LLLT is not sufficient. The analysis of the non-radiated and radiated tissues is required to elucidate the tissue response and efficacy of the laser therapy. The theory that is widely accepted is that the mitochondria are the powerhouse of the stem cells that cause hair growth. The LLLT ‘turns on’ the nutrient pump process that energizes the mitochondria, which leads to an increase in ATP and subsequent reversal of hair follicles from the dormant stage of growth called telogen, to the active growth stage called anagen.
This was a single site study. The length of time required to complete the study, under this protocol, inclusive of all subject therapy and tissue harvesting did not exceed 16 weeks. All subjects, of which there were five in total, were recruited by the Principal Investigator from his pool of medical colleagues and associates. No advertising of any type was required to recruit the five subjects.
Material and Methods
Subjects experiencing Androgenetic Alopecia. The total number of subjects numbered five. Age range was 19 to 59 years. Apparent good health. Each participant was subjected to a brief physical examination and the taking of a medical history including information on current treatment and prescription drugs. No blood work was required unless the cause of the loss of hair was in question. No previous involvement in other hair studies. No use of any hair growth agent within the last six months.
The LLLT device that was used is called the REVAGE670™. It is a low-level diode laser system, operating at 670 nanometers, containing thirty 4-milliwatt diode lasers affixed in a rotating helmet. The subject’s head was positioned within the helmet, which is similar to a hair dryer, until a sensor triggered the start of therapy. There was no contact between the subject and the device; only the laser light reached the subject’s scalp. Treatment lasted for approximately 15 minutes, but was dependent on skin type classifications. The laser automatically shut off after the treatment session was complete. There was no pre or post treatment care required, only that the subject’s hair was clean and did not contain spray or gel fixative agents. No safety eyewear was required during the treatment session.
After recruitment was complete, the five subjects were evaluated to determine Fitzpatrick skin type, which is required for prescribing the appropriate length of each laser treatment session. Each subject received two treatments per week for six weeks and one treatment per week for six weeks, totaling 18 laser treatments. The area of treatment was the vertex of the scalp. The initial visit included the harvesting of pre-treatment tissue samples. After the 18th treatment, tissue samples were harvested again from the designated area of laser treatment. It is proposed that this algorithm caused the physiologic changes to occur at the cellular level, which was theorized by experts in the field of Photomedicine and LLLT.
There were no validated questionnaires available for querying subjects about hair loss treatments and subsequent outcomes. Therefore, no questionnaires or subject diaries were employed for this study.
Prior to the first laser treatment session, but on the same day, a 3mm punch biopsy was harvested from the area designated as the treatment area for the laser. The procedure for harvesting the tissue was as follows:
A sterile field was prepared
1% lidocaine with epinephrine, (1-100,000) was injected to provide anesthesia
A single use, 3mm punch was used to harvest the tissue sample
A 6/0 dermal, polypropylene suture was used to make a primary closure of the site
The suture was removed between 7 to 10 days post-closure
The tissue sample was labeled with a number ONLY. A reference was maintained in the subject’s medical record identifying the tissue sample and the subject
The tissue sample was immersed in a preservative container and shipped to a research laboratory where the tissue analysis was performed under a different IRB approval. The laboratory was Wellman Center of Photomedicine. After analysis was completed by Wellman, the tissue samples were incinerated
A statement of findings from the Wellman Center researchers was submitted to the IRB upon completion of the study in its entirety
There were no known risks or discomforts associated with the laser treatments administered with the REVAGE670. Although it was not anticipated, there was a very slight risk of bruising, scarring and infection from the tissue harvesting and blood drawing procedures. All possible precautions were taken to prevent these unwanted effects. No other risks were anticipated. All subjects were monitored for changes in health status or for indications of any form of infection in the areas where tissue was harvested. The monitoring was performed, on each visit, by the physician investigator and his staff.
Summary of Results
There were eight before and after biopsies taken from four subjects to compare. There were four outcome measures: (a) number of hairs, (b) presence of anagen hairs, (c) number of hairs containing Melanin, (d) presence of Ki67, a marker of proliferating cells in the hair follicles. ALL FOUR subjects showed improvement in at least one of these measures in at least one pair of biopsies. Subject 5 had the most impressive overall improvement.
Each of the four subjects demonstrated an increase of melanogenesis. Based upon work published by Tobin, Hordinsky and Bernardz in the J. Investig Dermatolo Symp Proc 10:275 – 279, 2005, melanogenesis in the hair shaft, bulge and outer root sheath occurs only in Anagen I-IV. Such published research supports the theory that if red laser light causes an increase of melanogenesis, it must be stimulating the production of Anagen hairs, which would lead to more terminal hairs.
Before / After
Photos show typical results at 6 months of LLLT treatment.