Low intensity light is termed low level laser therapy (LLLT) which stimulates cellular activity in tissues. It is associated with a range of wavelengths from red to the infrared spectrum and promotes tissue repair and regeneration. This process of tissue repair by LLLT has been called photo biomodulation.
The optical window for biological tissue is 650-1200 nm. The tissue penetration is maximum at the wavelength of red and infrared (600-950) and is utilized in LLLT.
Hair Follicle undergoes repetitive cycles throughout the lifetime of the host. There are three cycles in each stage. They are,
- Anagen Phase- which is the stage of active growth.
- Catagen Phase- which is the stage of apoptosis and regression.
- Telogen Phase- which is the stage of rest.
Bulge stem cells are present in the region of the outer root sheath which is located just below the sebaceous gland.
The most important cells in the hair follicle are those contained in the dermal papilla. These cells produce the overall signaling that control the three phases of hair cycles. Stem cells which reside in the area of the hair follicle respond to signals from the dermal papilla and give rise to progenitor cells. The progenitor cells migrate deeply into the dermis. They then differentiate into matrix cells that produce the hair shaft and the sheath.
Growth factors identified in hair follicle cycles include,
- Fibroblast Growth Factor
- Hepatocyte Growth Factor
- Transforming Growth Factor-B
- Signal Transducer and Activator of Transcription 3
Androgenic alopecia is the most common type of hair loss that affects both males and females. This is caused by genetically susceptible individuals caused by androgen such as testosterone and its metabolite dihydrotestosterone. In this condition, there is a reduction of the proliferative activity in the hair follicle epithelium which causes miniaturization of the scalp hair and results in vellus hairs.
The cause of AGA is abnormal signaling, disruption of the progenitor cells and abnormal cell proliferation forms are the essential components of this disease.
Common methods for treatment of Androgenic Alopecia include,
- Surgical Hair transplantation
- Platelet Rich Plasma
- Low Level Light Therapy
The mechanism of action of LLLT in the treatment of hair loss is not fully known. It is felt that LLLT stimulates cellular activity in tissues. After the report that LLLT stimulated hair growth in lab animals, it was ultimately approved for human use in 2007 by the FDA. It was assumed to stimulate anagen phase in telogen hair follicles. LLLT prolongs the duration of the anagen phase and increases the rate of proliferation in active anagen follicles. It also promotes reparative regeneration as in wound healing. Therefore, in hair follicle disorders such as androgen alopecia, it normalizes physiological regeneration of the hair follicle.
In 1967, Mester et al. discovered the ability of lasers to induce hair growth using lasers in the red and infra-red wavelength on the backs of experimental lab mice undergoing cancer treatment. Hypertrichosis was a possible side effect of the treatment with laser therapy at wavelength low enough not to cause burning of tissues. It was found this treatment stimulated follicular growth. This stimulation was found to be one mechanism of the pro-regenerative effect of LLLT. However, after multiple studies, it was found that the stimulatory effect of laser phototherapy is mediated through an increase in the proliferative activity within the hair follicle epithelial matrix.
LLLT accelerates keratinocyte and fibroblastic mitosis by generating reactive oxygen species and antioxidants. The cellular chromosphere responsible for the effect of visible light is cytochrome c oxidase with absorption peaks in the infra-red region.
The mechanisms of action of LLLT are:
- Increased adenosine triphosphate production
- Modulation of reactive oxygen species
- Induction of transcription factors
The transcription factors enhance gene transcription and protein synthesis contributing to proliferation and migration. The overall effect led to proliferation, modulation in the levels of cytokines, increase in growth factors, increased tissue oxygenation and decrease in inflammatory mediators.
It has been further proven that LLLT decreases inflammatory prostaglandin E-2 and increases anti-inflammatory cytokines.
The stem cells of the hair complex live in a hypoxic environment. When stimulated by LLLT, the mitochondria are prompted into action. This stimulates mitochondrial activity and is accompanied by an increased demand for increased oxygen which is not available in the low oxygen environment of the hair complex. The increased intracellular reactive oxygen species following LLLT treatment triggers the differentiation of the stem cells. The stem cells then become progenitor cells and stimulate a cascade that terminates with the hair follicle entering the anagen phase of growth.
In multiple studies, in both men and women, LLLT was found to be safe, non-invasive and an effective treatment for patients with androgenic alopecia who do not respond to other treatments such as minoxidil. Also, LLLT has be found to have synergistic action when combined with other modalities such as platelet rich plasma or exosome administration. Due to LLLT
known beneficial effects on wound healing, it can also be used as an adjunctive therapy in hair transplant surgery to reduce healing time and increase graft survival.
Fac Rev 2022 Jan 12. Doi:10.12703/r/11-1. PMID 35156098
Purpose: This article reviews emerging evidence that has advanced our understanding of hair growth to provide a context for outlining current and emerging therapies.
Conclusion: A number of ongoing clinical trials are exploring novel treatments however, it is unlikely that one therapy alone will result in a desired, sustainable outcome. Combination therapy incorporating systemic therapy and adjuvant procedural modalities (PRP, LLLT, or laser) may well represent the optimal strategy to produce long lasting results, prior to surgical considerations.
- Efficacy of Non-Surgical Treatments for Androgenetic Alopecia: A Systemic Review and Network Meta-Analysis
J Eur Acad Dermatol 2018 Dec;32(12):2112-2125 PMID 29797431
Purpose: The aim of this study was to review recent advances in non-surgical treatments for androgenic alopecia and identify the most effective treatments
Conclusion: Results of this network meta-analysis indicate the emergence of novel, non-hormonal therapies as effective treatments for hair loss (PRP, LLLT). This analysis may aid physicians in clinical decision making and highlight the variety of non-surgical hair restoration options for patients.
J Am Acad Dermatol 2017 Jul;77(1):136-145. PMID 28396101
Purpose: This systemic review and meta-analysis assesses the efficacy of non-surgical treatments of androgenetic alopecia in comparison to placebo for improving hair density, thickness, growth or subjective global assessments done by patients or investigators.
Conclusion: This meta-analysis strongly suggests that minoxidil, finasteride and low-level light therapy are effective for promoting hair growth.
Author comment: minoxidil and finasteride must be taken continuously, or the growth stops and the patient reverts back to baseline. Also, these drugs have significant side effects ,some life threatening.
J Cutan Aesthet Surg 2021 Oct-Dec;14(4):385-391. PMID 35283601
Purpose: Low Level Light Therapy has been claimed to be a safe device-based modality for stimulating hair growth in both men and women in androgenetic alopecia. Fifteen studies were found and analyzed.
Conclusion: LLLT represents a non-invasive, safe, and potentially effective treatment option for patients with AGA who do not respond or are not tolerant to standard treatment of AGA.
Juventix Regenerative Medical is an industry leader in the regenerative medical field. Juventix offers multiple options for the regenerative clinician. These include platelet rich plasma devices and kits for processing, regenerative tissue products such as exosomes and the Dermamed LLLT.
- The Dermamend incorporates three levels of light treatments.
- Red Light Therapy at 630 nm for the skin and hair
- Blue Light Therapy at 450 NM for anti-inflammatory treatments as well as anti-infective post therapy treatments
- Infrared Light Therapy at 850 NM for deep tissue repair, cell rejuvenation, anti-aging and to decrease muscle and joint pain.
The Dermamend in on an easily movable platform and the wide canopy allows wider or larger application areas . The Dermamend LLLT is a stand alone option treatment for many therapeutic choices or can be used to compliment other regenerative therapies.
RESTORE, REVIVE, REGENERATE- JUVENTIX REGENERATIVE MEDICAL
Dr. Robert McGrath