— Expert Knowledge
Scientific Advisory Board
A clinically grounded overview of photobiomodulation — the mechanism, evidence, target applications, and dosing science behind every Ćelune device.
— Expert Knowledge
What is it?
Red light therapy, or Photobiomodulation (PBM), is the therapeutic use of non-ionizing red and near-infrared light (≈600–1000 nm) to modulate cellular function.
It is non-thermal at therapeutic doses — it does not burn or damage the skin, does not cause tanning, and is non-invasive. Light penetrates the skin to activate complexes that stimulate regeneration, repair, and collagen production.
— Wavelength Ranges
Spectrum
630–670nm
Red Light — superficial tissues, skin surface, collagen production
780–940nm
Near-Infrared— deeper penetration into muscle and joint tissue
How Does It Work?
At the cellular level, PBM primarily acts on the mitochondria where red light is absorbed by cytochrome c oxidase (Complex IV) in the electron transport chain. This increases ATP production, resulting in more cellular energy. This in turn modulates reactive oxygen species (ROS), nitric oxide (NO), and inflammation pathways — promoting gene expression related to healing and tissue repair. Think of it as “nudging” cells to function more efficiently rather than forcing a pharmacological effect.
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Gene Transcription
Activation of transcription factors (NF-κB, AP-1) leads to increased growth factors and elevated anti-inflammatory mediators.
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Improved Microcirculation
Nitric oxide (NO) release causes vasodilation, increasing blood flow and oxygen delivery to target tissues.
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Cellular Proliferation
↑ fibroblast activity, ↑ collagen synthesis, and ↑ angiogenesis — accelerating structural tissue repair at depth.
Target Areas
Pain Management & Rehabilitation
Reduces pain in osteoarthritis, tendinopathies (e.g. Achilles tendinitis), and back/neck pain.
↓ inflammatory mediators (prostaglandins)
↓ nerve conduction velocity in pain fibres
↑ endogenous opioids (endorphins)
↓ oxidative stress
Musculoskeletal Recovery
Faster recovery, improved function, and better tolerance of rehabilitation exercises.
↓ muscle fatigue (↑ ATP availability)
↓ inflammation in tendons and joints
↑ tissue repair capacity
Wound Healing
Faster healing of chronic ulcers and surgical wounds, with improved tissue quality.
↑ fibroblast proliferation
↑ collagen deposition
↑ angiogenesis (new blood vessels)
↑ ATP → faster cell turnover
Skin Rejuvenation
PBM smoothens skin, reduces fine lines, and improves acne via anti-inflammatory effects.
↑ collagen and elastin production
↓ inflammation
↑ keratinocyte turnover
Anti-Inflammatory Effects
Reduces swelling and stiffness, improves joint mobility — systemic but locally expressed.
↓ TNF-α, IL-1 cytokines
↑ anti-inflammatory mediators
Hair Loss (Androgenetic Alopecia)
Improves hair density and follicular activity in androgenetic alopecia.
Activates signalling pathways via hair follicle stimulation
↑ follicular energy availability
Light Therapy Dosing
The biphasic dose–response curve (Arndt–Schulz Law) describes how treatment intensity or duration influences biological effect. Therapeutic responses are not linear — there is a specific optimal window of exposure where the treatment delivers its greatest benefit.
Low Dose
— Insufficient photons
— Minimal mitochondrial activation
— Subtherapeutic response
Optimal Dose ✦
↑ Cytochrome c oxidase activity
↑ ATP production and energy
Controlled ROS signalling → repair and anti-inflammatory effects
High Dose
— Excess ROS → cellular stress
— Mitochondrial overload → ↓ efficiency
— Potential inhibition of healing pathways
Dosing Formula
Energy Density (J/cm²) = Irradiance (W/cm²) × Time (seconds) | Most therapeutic effects occur between 4–30 J/cm².
Irradiance
How much power hits each square centimetre of skin — the brightness or intensity of the device (measured in mW/cm²).
Fluence
Total energy delivered per session. Calculated as: Irradiance (mW/cm²) × Time (seconds) ÷ 1000. Expressed in J/cm².
Wavelength
Each wavelength penetrates to a different depth. Red (~630nm) reaches 1–3cm for skin and collagen; near-infrared goes deeper into muscles and joints.