One common type of hair loss, known as Alopecia, affects more than half of all people world-wide. The most common type, affects 50% of males over the age of 40 and 75% of females over 65. The National Institute of Health reports only two drugs have been approved so far (minoxidil and finasteride) for treatment. The NIH has reviewed the evidence for light therapy applied to the scalp as a treatment for hair loss and discusses possible mechanisms of actions.
Note: Low Level Laser Therapy (LLLT) and SMT LED’s can produce wavelengths at high enough power densities to prove effective. Power densities need to be equal to or greater than 90 mW / cm2 in order to be effective.
Conclusion
The National Institute of Health concludes “Controlled clinical trials demonstrated that LLLT stimulated hair growth in both men and women and found that LLLT for hair growth in both men and women appears to be both safe and effective. “
Here is the link to the NIH Report
Selected Excerpt from NIH Report
“It has long been known that red or near-infrared laser light promotes tissue repair and regeneration and low-intensity light called low-level laser therapy (LLLT) stimulates cellular activity [1]. After the discovery of lasers in the 1960s, there has been tremendous interest in using these laser devices to treat various medical conditions. The most commonly used devices have wavelengths in the range 500–1,100 nm (the so-called optical window of tissue)”
“LLLT has shown beneficial effects for a variety of medical conditions such as wound healing, nerve regeneration, joint pain relief, stroke recovery, and the prevention and treatment of mucositis [2–8]. Home-use LLLT devices that emit low power coherent monochromatic red light have been developed for various skin conditions, including hair growth [9]. In this review, we will focus on the use of LLLT as a potential treatment for several types of hair loss.”
“Using 655 nm red light and 780 nm infrared light once a day for 10 minutes, 24 male AGA patients were treated and evaluated by a group of investigators [54]. Evaluation has been performed via global photography and phototrichogram [54]. Following 14 weeks of treatment, increase in hair density on both the vertex (145.1/cm2 vs. 137.3/cm2 pre-treatment, P < 0.005) and occiput (163.3/cm2 vs. 153.3/cm2, P < 0.005) as well as anogen/telogen ratio (vertex: 84.7 vs. 79.7 pre-treatment and occiput: 91.9 vs. 89.6 pre-treatment) was observed, and 83% of the patients reported to be satisfied with the treatment [54]. “
“Satino et al. [55] tested the efficacy of LLLT on hair growth and tensile strength on 28 male and 7 female AGA patients.” ” Each patient was given a HairMax LaserComb® 655 nm, to use at home for 6 months for 5–10 minutes every other day [55]. ” ” In terms of hair count, both sexes and all areas had substantial improvement (for temporal area: 55% in women, 74% in men, in vertex area: 65% in women, 120% in men) with vertex area in males having the best outcome [55].”
NIH “Stages of hair cycle. Anagen stage is the growth stage which may last 2–6 years. In cagaten stage, club hair transitions upwards towards the skin pore and the dermal papilla begins to separate from the follicle. This phase usually lasts from 1 to 2 weeks. In telogen stage, the dermal papilla fully separates from the follicle and it takes about 5–6 weeks. Lastly, the dermal papilla moves upward to meet hair follicle once again and the hair matrix begins to form new hair, which represents the return to anagen stage. “