The integration of light-based therapies into wellness routines often causes confusion about whether infrared saunas and red light treatments are the same. Consumers frequently see saunas advertised with visible red lights and assume the heating function and the therapeutic light are a single combined system. This article clarifies the distinction between the two technologies. While both use light energy, they operate on different principles and are not always found together.
Understanding Infrared Saunas
Infrared (IR) saunas use electromagnetic radiation existing just beyond the visible light spectrum to generate heat. This invisible energy is categorized into three main types: near-infrared (NIR), mid-infrared (MIR), and far-infrared (FIR). Each type has a different wavelength and depth of tissue penetration. The goal of an infrared sauna is to induce a deep, systemic warming effect by heating the body directly, unlike traditional saunas that heat the surrounding air.
Far-infrared wavelengths (3 to 1,000 micrometers) are the most commonly used in infrared saunas because they resonate effectively with water molecules in the body. This resonant absorption causes water molecules to vibrate, generating heat from within the tissues and penetrating approximately 1.5 to 2 inches deep. This deep penetration raises the core body temperature, promoting sweat at lower ambient temperatures than a conventional sauna. This heating mechanism supports benefits like detoxification, improved circulation, and muscle relaxation.
The Mechanisms of Red Light Therapy
Red Light Therapy (RLT), also known as photobiomodulation (PBM), uses specific wavelengths of light, typically ranging from 630 nanometers (nm) to 850 nm. This light falls into the visible red and non-thermal near-infrared spectrum. Its function is not to create heat, but to work at a cellular level by delivering photons absorbed by the mitochondria.
The enzyme cytochrome c oxidase within the mitochondria absorbs these photons, triggering photochemical reactions. This process increases the production of Adenosine Triphosphate (ATP), the primary energy currency for cellular activities. Increasing ATP enhances cellular function, providing the energy needed for repair and regeneration. The biological effect is non-thermal, focusing on stimulating cellular processes to aid in healing and reduce inflammation.
Why Infrared and Red Light Are Separate Systems
Infrared heating panels are engineered for high thermal output and broad infrared spectrum emission to heat the body. Dedicated red light therapy devices, in contrast, emit precise, concentrated wavelengths of red and near-infrared light at a specific intensity (irradiance) without generating significant heat. The visible light seen in sauna heating panels is often a byproduct of heat generation, not the output of a specialized RLT panel.
A standard infrared sauna is fundamentally a heating system, using wavelengths above 1,000 nm for thermal effects. Some saunas, known as “full-spectrum” models, incorporate near-infrared (NIR) wavelengths that overlap with the RLT spectrum, but they still prioritize thermal delivery. The inclusion of a separate RLT system, which delivers the targeted 630–850 nm wavelengths with the necessary irradiance for photobiomodulation, is a distinct design choice and an added feature. While many modern saunas integrate red light features to “stack” benefits, they remain separate technologies serving different purposes within the same enclosure.
Distinct Therapeutic Benefits
The core therapeutic benefit of the infrared sauna is its systemic effect, driven by deep, penetrating heat. The increase in core temperature and subsequent sweating supports detoxification, improves cardiovascular health, and offers whole-body relaxation. This heat-based therapy is effective for general wellness and chronic conditions that benefit from improved blood flow and muscle loosening.
Red light therapy excels at localized and targeted cellular repair without relying on heat. By stimulating mitochondria, RLT accelerates skin rejuvenation, promotes collagen production, and aids in the healing of wounds and muscle tissue. This therapy is preferred for specific issues like inflammation, joint pain, or skin health, where the goal is tissue-level regeneration rather than full-body thermal stress. While both therapies contribute to overall wellness, one focuses on heat-driven systemic benefits and the other on light-driven cellular activation.