Far Infrared Light – White Paper

What is Far Infared (FIR) Light Therapy?
April 6, 2018
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Far Infrared Light – White Paper

What is Far Infrared (FIR) Light Therapy?

By Susan B Wozniak, RN, MSN

Far Infrared is part of the electromagnetic (light) spectrum that has biologic effects which stimulate cells and tissue, and which is considered a promising treatment for certain medical conditions, as well as improving physical performance. Light therapy has been used in many cultures for thousands of years. With the development of better technology, including FIR fabrics, to deliver FIR to the body, the benefits from its effects have widened. Special FIR lamps (saunas) as well as garments made of fibers containing FIR-emitting ceramic nanoparticles are now being used to deliver these effects.

Biologic effects: FIR interacts with biological structures including cells, cell membranes, water, and DNA/proteins. FIR’s interaction with biological mechanisms can be framed in terms of altered cell membrane potentials and altered mitochondrial metabolism. The mitochondria are the energy factories within each cell. FIR wavelengths are invisible–too long to be perceived by the human eye, but the body experiences FIR energy as a gentle radiant warmth which can penetrate up to 1.5 inches (about 4 cm) beneath the skin. However, even levels of FIR that do not produce any detectable skin heating can also have biologic effects  (Vatansever & Hamblin, 2012).

Some biologic effects observed in medical studies include: An in vitro study (Yu, et al) revealed significantly quicker wound healing and growth factor expressing myofibroblasts and collagen content were increased. In induced limb ischemia, blood perfusion as well as significantly increased capillary density was observed by Akasaki et al, during an in vivo study. In another exciting study, Ishibashi et al demonstrated that FIR may be used as an effective medical treatment for certain cancer cells.

Ting-Kai Leung and colleagues found that FIR delayed the onset of muscle fatigue induced by muscle contractions, and in another study, increased generation of intercellular nitric oxide (NO) production. Nitric oxide is known as an endothelium-derived relaxing factor. The endothelium (inner lining) of blood vessels uses nitric oxide to signal the surrounding smooth muscle to relax, thus resulting in vasodilation and increasing blood flow. Popular medications such as Viagra® depend on this mechanism to work. FIR has also been shown to inhibit cytotoxity and inflammation. Lueng et all demonstrated significantly higher cell survival rates after exposure to x-rays, through an anti-oxidant mechanism (2011).

FIR has also been shown to improve cardiac and vascular function, relieve stress and fatigue, and relieve pain and stiffness. Another study showed that FIR reduced symptoms of exercise-induced muscle damage in athletes after a simulated trail running race. FIR blankets have been shown to improve quality of sleep, inducing quicker and longer-lasting REM sleep.

With FIR-emitting fabrics being employed as therapeutic as well as performance-enhancing devices, it is pertinent to examine the thermodynamics of the process. The first law of thermodynamics states that energy can neither be created nor destroyed. Heat (molecular vibrational energy) is transferred from one body to another in three forms: radiation, convection, and conduction. It is clear that the principal source of energy needed to power the FIR emissions from the garments to the human body comes predominately from the human body itself, as well as a bit from ambient light and heat in the environment, since the body is at a significantly higher temperature than the surrounding air. This energy is transferred to ceramic particles embedded in FIR fabric, which absorb the heat energy, maintain the temperature at sufficiently high levels, transforming it into light, which is then emitted and reflected back into the body in the form of FIR. Although this may appear to be an energy-neutral process, cancelling itself out, this is not the case, because the ceramic particles prevent the loss of energy that would have otherwise escaped through normal clothing. Thus the body’s energy becomes “recycled”.

Mechanisms of heat-transfer from the body to heat-absorbing ceramic particles, with a net gain of FIR include convection, conduction, or both. The balance between convection and conduction will depend on how close the garment is to the skin. If it is skin-tight, conduction is important, if loose-fitting, then convection—heating of the air between skin and garment–may be important.

What Far Infrared Can Do For You: Practical Applications of FIR

FIR exposure induces increased microcirculation, independent of thermal (warming) effects, as shown through low-level exposure of human umbilical cells increasing levels of nitric oxide and other factors (Vantansever & Hamblin, 2012).  Therefore, the popular opinion among doctors that the effects of FIR are solely effected by heat is unfounded. Footwear and socks have been worn and studied (York & Gordon, 2009) and are being marketed as diabetic and cramp-preventing socks (Energy Textiles, LLC) and therapeutic soles for shoes. Hologenix received FDA designation as a medical device for FIR shirts, approved to claim increased energy, temporary increased blood flow, better endurance, faster recovery, enhanced performance and stamina, more speed, and increased comfort and promotion of better sleep. Innovative retailers such as Hammacher-Schlemmer carry pajamas promoting quicker induction of REM sleep. Pillows, seat cushions, sheets, back braces, and wraps have also been developed for the athlete and people in need of recovery (Energytextiles.com). Higher levels of particles embedded in fibers do increase heat and are used in gloves, outerwear, blankets, and scuba diving suits. Unexpected benefits of using FIR yarn in footwear include quick evaporation of moisture, keeping feet dry and odor-free; as well as providing a mild exfoliating effect from the particles embedded in the yarn.

Reduction of cellulite, body measurements, and weight reduction have been studied; improved cardiovascular health, dysmenorrhea relief, lactation enhancement, pain relief, stress relief, and potential cancer treatments have also been researched. Specific syndromes such as Raynaud’s have also been studied with positive results from FIR therapy.

Theoretical Applications/Indications for Further Research

With success in practical applications of FIR reaching the marketplace, new ideas for the technology are being developed and the indications for further research are limited only by the imagination. As a nurse, this author is particularly interested in therapeutic uses which don’t require medications, with their associated side effects, and which hold promise to improve the lives of many, throughout the life continuum. From premature infants, who have sometimes severe consequences of blood shunting to major organs away from intestines with resulting necrosis, to diabetic patients with neuropathy and foot gangrene and amputation, the potential implications of increased blood flow are huge. Athletes are using FIR for longevity in sport (Tom Brady), as well as improving performance, which can be applied to other groups, including the military. And research on earth can be extended to the study of FIR in microgravity in space, where materials often behave differently, i.e.: cell growth and creation of new medications, and the study of heat transfer methods like conduction.


Light therapy has been used in many cultures for thousands of years. Far-Infrared light is part of the electro-magnetic light spectrum that has biologic effects which stimulates cells. It has been proven to be a promising treatment for many conditions, and has physiological effects resulting from increased blood flow. The primary source as well as beneficiary of recycled energy is the human body. FIR benefits include, but are not limited to: Increased energy, better endurance, strength, stamina, and speed; better sleep quality, more comfort, quicker recovery, and thermoregulation. Successful practical applications have reached the consumer marketplace, leading to more indications for research.


Sources: Vatansever, F. and Hamblin, MR. Far infrared radiation (FIR): its biological effects and medical applications. Photonics Lasers Med. 2012 Nov 1;4 255-266. (PubMed)

Lueng TK, Lin YS, Lee CM, Chen YC, Shang HF, Hsiao SY, Chang HT, Chao JS. Direct and indirect effects of ceramic far-infrared radiation on the hydrogen peroxide-scavenging capacity and on murine macrophages under oxidative stress. J Med Biol Eng. 2011; 31 (5): 345-51.

Tei C, Shinsato T, Miyata M, Kihara T, Hamasaki S. Waon therapy improves peripheral arterial disease. J Am Coll Cardiol., 2007, 50☹22):2169-71 (PubMed)

York RM, Gordon IL. Effect of optically modified polyethelene terephthalate fiber socks on chronic foot pain. BMC Complement Altern Med. 2009, 9:10 (PubMed)

Yu SY, Chiu JH, Yang SD, Hsu YC, Lui Wy, Wu CW. Biological effect of far-infrared therapy on increasing skin microcirculation in rats. Photodermatol Photoimmunol Photomed. 2006; 22 (2): 78-86. (PubMed)

Ishibashi J, Yamashita K, Ishikawa T, Hosokawa H, Sumida K, Nagayama M, Kitamura S. The effects inhibiting the proliferation of cancer cells by far-infrared radiation (FIR) are controlled by the basal expression of heat shock protein (HSP) 70A. Med Oncol. 2008; 25(2):229-37. (PubMed)

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