Red and near-infrared wavelengths penetrate differently and should not be treated as interchangeable.

Red vs near-infrared light

Last reviewed 3 August 2026. How we write this.

Red and near-infrared wavelengths penetrate differently and should not be treated as interchangeable.

Visible red light is absorbed more superficially; near-infrared reaches deeper tissue, although penetration depends on wavelength, skin, power and geometry.

Match wavelength to the studied outcome

A device containing a popular wavelength is not proof it reproduces a trial. Irradiance, distance, exposure time and treatment area determine the delivered dose.

Educational content only. This does not diagnose, treat or replace individual advice from an appropriately qualified clinician.

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Sources for this classroom

Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.