The effects of LLLT are photochemical, i.e. like photosynthesis in plants. Red and near infrared light affect cell membrane permeability and aid the production of ATP thereby providing the cell with more energy which in turn means the cell is in optimum condition to play its part in a natural healing process. Because of the low power energy of low level laser therapy, the effects are not thermal, i.e. do not cause heating, and therefore cannot cause damage to living tissue.


1st law of Photochemistry – Light must be absorbed by a chromophore to initiate a photochemical effect and thus ultimately have a biological effect.


Laser light energy is absorbed by chromophores and cytochromes located on the mitochondria known as the cell “engine”.


Here the laser energy is converted into chemical energy “super charging” the cell into accelerating the natural healing processes of tissue


Phototherapy has been shown to affect cellular activity in the following ways:

  • stimulate cell growth

  • increase cell metabolism

  • improve cell regeneration

  • produce an anti-inflammatory response

  • produce an edema reduction

  • reduce fibrous tissue formation

  • stimulate nerve function

  • reduce the production of substance P

  • stimulate long-term production of nitric oxide

  • decrease the formation of bradikynin, histamine and acetylcholine

  • stimulate the production of endorphins.


Cellular effects of phototherapy can be classified into primary (light-induced), secondary (which occur in response to the primary effects) and tertiary effects (Schindl et al, 1999; Stadler et al, 2004; Dyson, 2006). There are three effects that commonly occur as a result of tissue exposure to light photons:


Primary effects due to photoreception and the direct interaction of photons with cytochromes are very predictable and unique to phototherapy. Photoreception generally is followed by transduction, amplification and photo-response, the last of which can be classified as either secondary or tertiary.


Secondary effects occur in the same cell in which photons produced the primary effects; they are induced by these primary effects. Secondary effects include cell proliferation, protein synthesis, degranulation, growth factor secretion, myofibroblast contraction and neurotransmitter modification, depending on the cell type and its sensitivity. Secondary effects can be initiated by other stimuli as well as light.


Tertiary effects are the indirect responses of distant cells to changes in other cells that have interacted directly with photons. They are the least predictable because they are dependent on both variable environmental factors and intercellular interactions. They are, however, the most clinically significant. Tertiary effects include all the systemic effects of phototherapy


How does healing occur?


Cells that lack energy are unable to participate in the healing process until enough Adenosine Triphosphate (ATP) has been produced. works by stimulating the mitochondria of the cell, the cell engine, to produce ATP at a higher rate. Cell energy is produced by the Mitochondria by absorbing Glucose molecules and converting them to ATP molecules.


When red light is applied directly to the cell, light energy is converted into chemical energy (First law of Photo Chemistry). The process of converting Glucose to ATP is rapidly increased through the Mitochondria, (Kreb’s Cycle / Electron Transport Chain) allowing the cell to replicate faster. When the cell has produced enough ATP to perform cell division, it can start to participate in the healing process. Energised cells will build upon one another, rebuilding the damaged area and healing the patient’s condition on a cellular level.


Cellular pathways: There are a number of pathways which we are currently researching on, but the two completely understood are explained here under.


Cellular pathway No. 1 - Mitochondria takes glucose (food that we ingest), turns it into a simple sugar, and transforms it into Adenosine Triphosphate, the basic energy source of all cells.


In the production of ATP, there is Cytochrome c Oxydase, (used in the redox cycle), which is a light sensitive protein which is activated by certain wavelengths of light which is about 630nm to 670nm, peaking at around 650nm to 660nm range


Cellular pathway No. 2 – Also done in the Motichondria, is the production of Nitric Oxide. Nitric Oxide causes temporary vasodilation in capillaries, so they open up in size, hence bringing more blood, more oxygen, and fuel molecules to injured tissue, hence accelerating the healing by upto a 100%.


Further, Super Pulsed laser systems boost production of Nitric Oxide up to 700% more nitrous oxide for vasodilation of capillaries compared to virtually zero from placebo or continuous wave lasers.


Low Level Laser Therapy

Theralase, Inc. Canada



Introduction to Laser Therapy


How does it work?






Contra - Indications


Conditions treated


Pain Management


Wound Healing


Arthritic Conditions




Addiction Rehabilitation




Why Theralase LLLT?