Low Level Laser therapy is also now known as PhotoBioModulation (PBM) and perhaps more helpfully so, since its action involves the modulation of the biological activity of the body through the controlled delivery of light which is monochromatic and usually but not always coherent laser light.
The therapeutic effects of PBM treatment were discovered by Endre Mester, a professor of surgery, who observed improved hair growth and healing in tissue adjacent to his laser surgery but where only a low laser dose was received. His subsequent work provided the initial volume of evidence for the efficacy of laser in healing.
Research has since shown the therapy to be dose dependent with effects which are bi-phasic in response but delivering appropriately low levels of light energy remains fundamental to achieving the desired biochemical effects. Low Level Laser Therapy equipment delivers the range of required light energy density with negligible thermal effect thus avoiding tissue damage through heat from excess power.