Propionibacterium acnes synthesize and store a large amount of porphyrins. Once the porphyrin is exposed to visible light it becomes chemically active and transfers to an excited state, resulting in the formation of singlet oxygen, which combines with cell membranes to destroy P.acnes. This process is dependent on the rate of production of excited porphyrins, the concentration of photons, the temperature and the wavelength of the photons. LHE acts as a catalyst to produce the required photochemical reaction from porphyrin activation to oxygen production. This ability is based on three controlled parameters, those of wavelength, overall concentration of photons and temperature.
Although porphyrin is thought to be most reactive to wavelengths in the 400-430nm, the blue spectrum does not penetrate as well as other wavelengths. Often, not enough protons reach the target. To optimize the tradeoff between the penetration depth required and porphyrin activation efficacy, LHE utilizes a higher range of the light spectrum including green, yellow and red.
This offsets the loss in absorption with a more direct targeting of actual porphyrin. More photons reach the target and less photons are wasted at ineffectual depth penetrations.
The Arrhenius equation describes the rate of production of excited porphyrin molecules as a function of temperature. For most chemical reactions, elevating the temperature by 10°C will double the speed of the reaction. By combining direct heat with the light pulse, LHE further raises the temperature inside the follicle affecting a much faster chemical reaction time than light alone would generate. The generated heat also aids in reducing inflammation, opens pores and soothes the pain often associated with acne.