Clinical Research Designed to Explain the Process of Action for Low Level Laser Therapy and Red Light Therapy in Hair Regrowth
Title of Study
The physiologic effects of LLLT on human follicular cells surrounding dermal tissue structures
The objective of this study was to determine the safety and physiological effects when the hair follicle and the surrounding tissues are subjected to the radiation exposure that occurs during LLLT.
Existing data is from murine models and cannot be extrapolated for human subjects. To accurately analyse the effects of this type of radiation, radiated and non-radiated tissue analysis is required in order to elucidate the efficacy of the therapy, the response within the tissue, and the safety of the treatment. The widely accepted theory is that Low Level Laser Therapy (LLLT) “switches on” the nutrient pump, which invigorates the mitochondria (the stem cell “powerhouses”). In turn this increases levels of ATP, which reverses the dormant growth stage of the hair follicles, known as telogen, putting them back into an active stage of growth, known as anogen.
Sites of Study
This single site investigation, inclusive of tissue harvesting and patient therapy, was completed within 16 weeks. Five subjects took part, all of whom were enlisted by the study’s Principal Investigator, from a pool of his associates and medical colleagues. No advertising was necessary to enlist the subjects.
Methods and Material
Both female and male subjects experiencing thinning hair, hair loss or androgenetic alopecia took part. There were five subjects, two male and three female, all in good health, aged 19-59. Each subject was given a short physical exam and was asked to describe their medical history to the examiner – including their current health and any prescription drugs or current treatments that they were using for their hair loss. No blood was drawn, unless the underlying cause of the participant’s hair loss was unclear. Participants had no previous engagement in any other hair loss studies and had not used any kind of hair loss agents within the six months preceding the study.
Protocol for Treatment
The Low Level Laser Therapy device used throughout the study was the REVAGE670™, a system using 30 four milliwatt low level lasers, operating at a rate of 670 nanometers, all affixed within a pivoting helmet. The helmet was placed over the participant’s head and a sensor within the helmet triggered the beginning of therapy. Treatment time varied dependent upon skin type; although the average was 15 minutes. No contact was made between the helmet and the scalp at any time, and only the light from the laser reached the scalp. The device was programmed to automatically switch off the laser once the therapy was complete. The only pre and post therapy care required was that the participant’s hair be clean and free of fixatives and gels. No safety goggles were required.
Once the participants were recruited, each were evaluated in order to determine their skin type on the Fitzpatrick scale, for the purposes of determining the appropriate treatment time for each participant. Each participant received 18 treatments in total, three per week over a course of six weeks. The treatment area was the scalp vertex. The therapy regimen was preceded by a pre-treatment visit with a physician where tissue samples were taken. Following the 18th laser treatment, samples were again taken from the LLLT treated area of the scalp. This study hypothesised that this treatment protocol caused physiological changes within the follicles at a cellular level, as theorised by LLLT and photomedicine experts.
There was no validated questionnaire regarding hair loss and treatments for hair loss available at the time of the study. Therefore, no subject diaries nor questionnaires were given to the participants.
Before the initial laser therapy session (within the preceding 24 hours) a punch biopsy of 3mm wide was taken from the designated LLLT treatment area of each participant. The harvesting procedure is outlined as follows:
- The tissue field was made sterile
- A 1% lidocaine solution with epinephrine at a concentration of one to 100,000 was prepared and injected, providing anaesthesia
- The sample tissue was harvested using a 3mm (single use) punch
- The site was closed using a 6/0 dermal suture
- The sample was labelled using a number. In order to identify the tissue sample and the participant, references were made in the participant’s medical record to the number used to label the sample
- The sample was preserved in an airtight container, before being taken to the Wellman Centre of Photomedicine for tissue analysis under IRB approval. Once analysis was complete, the sample was destroyed
- Researchers submitted a statement to the IRB of their findings once the study was completed
The laser therapy administered by the REVAGE670 was not associated with any risk or discomfort. However, risks associated with the blood draw and tissue harvesting procedures included scarring, bruising and infection at the harvesting site, although this was unforeseen. All necessary safeguards were employed in order to avoid these side effects. There were no other anticipated risks. Throughout the study, all participants were closely monitored for signs of infection around the tissue harvesting sites and changes in current health status by the principal investigator and the investigator’s colleagues.
Summary of Results
A total of eight biopsies were taken to compare: four before the therapy and four following the therapy. Outcome measures included 1) the number (amount) of hair, 2) the presence of hair in the anagen stage of growth, 3) the number (amount) of hair containing melanin and 4) the presence of the marker ki67, indicating proliferating cells within the follicles. An improvement was seen in one or more of the outcome measures in all participants. Subject 5 in particular had a remarkable overall improvement.
A melanogenesis increase was noted in each participant. According to previous published work by Tobin et al in 2005, melanogensis occurs in the root sheath and the bulge of the hair shaft only when in a state of anagen I-IV. Published research such as this indicates that if LLLT increases melanogenesis, it stimulates the production and growth of anagen hair, leading to an increase in terminal hairs.