Physiological Effects of Low Intensity Laser Therapy

What is Laser Therapy?

Laser therapy is the use of monochromatic light emission from a low intensity laser diode (250 milliwatts or less) or an array of high intensity super luminous diodes (providing total optical power in the 1000-2000 milliwatt range) to treat musculoskeletal injuries, chronic and degenerative conditions and to heal wounds. The light source is placed in contact with the skin allowing the photon energy to penetrate tissue, where it interacts with various intracellular biomolecules resulting in the restoration of normal cell function and enhancement of the body’s healing processes. The following chart outlines the specific effects of Low Intensity Laser Therapy.

Clinical information

Short Term Effects

Long Term or Cumulative Effect

Other Effects

It should be noted that many other positive physiological activities are modulated and extensive research is currently in progress to fully explore these changes.


Absorption as a result of photon bombardment of various bio-molecules in the cell results in the transformation of light into biochemical energy. This is a cumulative effect and requires sufficient stimulation in order to initiate response. Typically 5-20 treatments varying from 15-60 minutes in duration are required. The end result of low intensity laser irradiation is the restoration of normal function of the cell unit. Conversely, worldwide research to date has failed to record any negative effects from this process. It should be noted that normally functioning cells are not adversely affected by the irradiation. In contrast to other therapies, Low Intensity Laser Therapy is curative rather than simply modulating symptomatology.