Low level laser therapy (LLLT)- is also known as photobiomodulation (PBM), low-power laser therapy (LPLT), soft laser therapy, low-intensity laser therapy, low energy laser therapy, cold laser therapy, bio-stimulation laser therapy, photo-biotherapy, therapeutic laser, and monochromatic infrared light energy (MIRE) therapy.  When applied to acupuncture points, the therapy is known as laser acupuncture.  These techniques employ a low level laser of 20-250mW at various wavelengths, durations, dosages, and frequencies for a variety of maladies, including the use of low level lasers or light emitting diodes (LEDs) as a treatment for hair restoration and musculoskeletal conditions including carpal tunnel syndrome, rheumatoid arthritis, osteoarthritis, wound healing, diabetic neuropathy, smoking cessation, TMJ disorder treatment, etc.   The treatment wavelength band seems to be primarily in the infrared spectrum.  Low level laser treatment first started in 1967.   Low level laser therapy is frequently used by chiropractors and as an alternative medicine, however the results of many studies show only short term improvement if any at all. Yet, there is some evidence of effectiveness in the alpha evidence presented here.  Bone graft healing shows a positive effect at higher power and low dose or with low power and high dose (repetitive treatments) (Photomed Laser Surg. 2017 Dec;35(12):649-658).  A review of LLLT found the therapy is effective for hair regrowth in male or female pattern hair loss.  (Lasers Med Sci. 2016 Feb;31(2):363-71.)   LLLT modestly improves carpal tunnel pain for 5 weeks but diminishes rapidly after that point (Arch Phys Med Rehabil. 2017 Jun 16).  LLLT was found to improve grip strength in patients with carpal tunnel syndrome (Lasers Med Sci. 2017 Aug;32(6):1439-1448).  The most favorable outcomes were reported in the 780-860mn wavelength range with 10 J/cm2 dosage (Physiother Theory Pract. 2017 Mar;33(3):184-197).  There is evidence that LLLT treatment of pressure ulcers is effective using the 658nm wavelength but not at wavelengths above 658nm (Lasers Med Sci. 2017 May;32(4):937-944.)   Peripheral somatosensory neuropathy including diabetic neuropathy has been successfully treated with LLLT with short term results with lasers 660-860nm, power 20-250mW, and energy density 0.45-70J/cm2 (Lasers Med Sci. 2017 Apr;32(3):721-728).  LLLT is not recommended for subacromial pain syndrome (Br J Sports Med  2016 Sep;50(18):1124-34)

.  There is low level evidence that LLLT is effective for chronic low back pain (Agency for Healthcare Research and Quality (US); 2016 Feb. Report No.: 16-EHC004-EF.
AHRQ Comparative Effectiveness Reviews.)