Photobiomodulation is associated with which outcome?

• A. It modulates cellular signaling to reduce inflammatory mediators and promote tissue repair
• B. It reduces inflammatory mediators through thermal effects
• C. It directly increases immune cell counts in the treated area
• D. It replaces the need for physical therapy

Answer: (A)

Photobiomodulation works by light triggering cellular signaling rather than simply heating tissue. Photons are absorbed by mitochondrial chromophores such as cytochrome c oxidase, boosting cellular energy and activating signaling pathways that shift the inflammatory milieu toward healing. This results in reduced inflammatory mediators and supports tissue repair processes like collagen synthesis and angiogenesis. The effects are largely non-thermal at therapeutic doses, so the main mechanism isn’t heat. It doesn’t directly increase immune cell counts in the treated area, and it’s best used as an adjunct to physical therapy rather than a replacement.