What Is Whole Body Red Light Therapy?

Today, red light therapy is widely marketed for a variety of applications, with a growing number of reported uses. These include areas such as tissue support, general wellness, skin care, and other topical applications. However, it is important to note that many of the claims associated with red light therapy—such as those related to immune function, hair retention, mental health, and other medical conditions—have not been evaluated or cleared by the U.S. Food and Drug Administration (FDA), nor are they necessarily supported by sufficient clinical evidence or covered by insurance providers.

A wide range of red light therapy devices are available on the market, varying in cost and specifications. There is currently no uniform consensus on the ideal parameters or outcomes associated with treatment.

This overview will outline what red light therapy has been cleared or studied for, as well as where evidence is limited or lacking. The underlying science of light-based applications spans multiple disciplines, including physics (light–tissue interaction, tissue optics, light source characteristics), chemistry (chromophore behavior, light absorption, photochemical processes), and biology (cellular response pathways, signaling mechanisms, and proliferation processes).

We will also outline “5 Keys for the Best Red Light Therapy Results” based on established usage guidelines and manufacturer recommendations.

What is Red Light Therapy?

Red light, when used alone at shorter wavelengths, is commonly directed toward the skin for general cosmetic or surface-level applications, as these wavelengths do not reach deeper layers of tissue.

When red light is used in combination with near-infrared wavelengths (longer wavelengths), the modality is often referred to as Photobiomodulation Therapy (PBMT). PBMT typically involves the application of red and near-infrared light to targeted areas of the body. The interaction of these wavelengths with tissues has been studied for its potential to influence biological processes.

This type of light is absorbed by chromophores within cells—particularly in mitochondria—where it may support cellular energy dynamics. Laboratory research has suggested that these wavelengths may play a role in supporting ATP (adenosine triphosphate) production, which is essential for cellular energy transport.

PBMT has also been explored for its potential to support the body’s natural response to oxidative stress. Oxidative stress involves an imbalance between free radicals and antioxidants in the body and is a subject of ongoing scientific investigation. Some research has indicated that light exposure may assist in maintaining cellular environments that help regulate oxidative processes.

PBMT has been studied in a variety of contexts, including its potential effects on tissue function, relaxation, and muscle performance. It is considered non-invasive and generally well-tolerated, with no widely reported adverse effects when used as directed.

The Following Applications Are Cleared by the FDA:

• Muscle relaxation and relief from muscle spasms
• Temporary treatment of minor muscle and joint discomfort
• Temporary relief of minor pain and stiffness associated with arthritis
• Temporarily increase local blood circulation
• Improve joint mobility ​

What Red Light Therapy Is Not

Some companies market red light therapy devices for uses that are not cleared by the FDA. It is important to understand that such uses may fall outside the scope of currently recognized regulatory clearances.

NOTE: The FDA does not "approve" medical lasers in the general sense. Instead, certain medical laser devices may receive FDA 510(k) clearance for specific intended uses. The use of the term "FDA Approved" in connection with red light therapy devices may be misleading and is not appropriate unless referring to a drug or device that has undergone formal FDA approval, which is distinct from clearance.
Source: https://www.aspenlaser.com/the-difference-between-fda-registered-fda-approved-and-fda-cleared/

The following are examples of conditions for which red light therapy has not been cleared by the FDA:

Cancer: Red light therapy devices are not cleared by the FDA for the treatment of cancer. Surgical lasers may be used in procedures involving cancer, and certain therapy lasers have been cleared for pain relief or recovery following cancer treatment. Photodynamic therapy (PDT) systems that include photosensitizing agents and light (including red light) may be FDA cleared for specific oncologic indications.

Psoriasis: The FDA has not cleared red light therapy for the treatment of psoriasis. Other technologies, such as UVA/UVB phototherapy and Excimer lasers at 308nm, are commonly used in clinical dermatology for psoriasis treatment and may have appropriate FDA clearances.

Depression: Red light therapy is not cleared by the FDA for the treatment of depression, including seasonal affective disorder (SAD). Instead, full-spectrum light boxes producing 10,000 lux and certain blue light devices are used for SAD and circadian rhythm-related conditions.

Wounds: The FDA has not cleared red light therapy for wound treatment. Infrared therapy devices are sometimes used in veterinary contexts for treating animal wounds, but this does not imply FDA clearance for human wound care.

Red Light Therapy Panels Are Not Therapy Lasers

Many red light companies use terminology that may not accurately describe red light therapy devices. Terms such as Low Level Laser Therapy (LLLT), cold laser therapy, soft laser therapy, low-intensity laser therapy, low-energy laser therapy, and biostimulation laser therapy are often used interchangeably. However, red light therapy panels are Light Emitting Diode (LED) systems, not lasers.

LED systems emit light in multiple directions, producing a diffused and incoherent output. In contrast, laser devices emit light in which the waves are coherent, meaning they are synchronized in both time and space, resulting in a concentrated and focused beam. These differences are important in distinguishing between device types and their respective classifications and intended uses.

Misuse of Laser Clinical Studies in Red Light Therapy Marketing

Of the thousands of referenced and reported clinical and scientific studies available, many are conducted using therapy laser devices as the light source. However, some red light therapy companies reference these laser-based studies in marketing materials to imply similar outcomes for LED-based systems. These references are sometimes used to suggest support for uses that are not FDA-cleared, including conditions such as cancer, wound healing, and immune-related effects, which may result in misleading marketing claims.

5 Keys for the Best Red Light Therapy Results

Key #1: Focus on Supporting Overall Wellness Rather Than Masking Discomfort

A common approach in healthcare is to manage immediate discomfort rather than addressing contributing factors. This may result in temporary relief without addressing the underlying causes. Various therapeutic modalities such as TENS, ultrasound therapy, vibration, massage, heat, and cold therapy products are often used to manage symptoms. While these may provide short-term comfort, they are not intended to cure or resolve the root issue.

According to the CDC, approximately 1 in 6 Americans live with persistent pain. Many individuals managing ongoing discomfort may rely on medications, including opioids and over-the-counter (OTC) products. Over time, tolerance to certain medications can develop, potentially increasing the need for higher dosages, which may elevate the risk of side effects, including cardiovascular and gastrointestinal concerns. Many OTC pain medications are not intended for long-term use.

Source: https://www.cdc.gov/drugoverdose/index.html

Relying solely on symptom management may increase healthcare costs and may impact overall well-being.

Light-based modalities, such as red light therapy, are being explored as non-invasive options intended to support general wellness and tissue comfort. These technologies use specific wavelengths of light and are designed to deliver light energy to targeted areas of the body. FDA-cleared devices are indicated for uses such as temporary relief of minor muscle and joint pain, minor arthritis pain or stiffness, promoting relaxation of muscle tissue, and increasing local blood circulation temporarily.

Summary: A comprehensive approach to managing discomfort may include the use of light-based products that are FDA-cleared for specific indications. Not all red light devices are created equally—wavelengths, energy output, and coverage vary. Users should ensure that any light therapy device is manufactured in compliance with FDA regulations and is cleared for its intended use.

Key #2: Combine Red Light with Multiple Infrared (IR) Wavelengths

Red is a part of the electromagnetic radiation visible spectrum that includes violet, indigo, blue, green, yellow, orange, and red, arranged in order of increasing wavelength and decreasing frequency. This narrow band of visible light is also known by the acronym ROYGBIV. Red is a short wavelength in the 600–700 nm range.

Red light has been used in various clinical and wellness settings for many years, particularly in dermatological contexts. For example, some research and clinical uses have explored applications for skin conditions such as acne and rosacea. These applications do not require deep tissue penetration. Red light may also be used alongside blue light in certain settings, as blue light is shorter in wavelength and may interact differently with surface-level factors.

Source: https://www.ncbi.nlm.nih.gov/pubmed/17903156

Some red light therapy companies claim their products penetrate tissues to specified depths. These often cite figures such as “8–10 mm.” However, converting to U.S. measurement units shows this equals less than ½ inch (12.7 mm), which aligns with absorption levels associated with surface-level or skin-directed light applications.

The Grotthuss-Draper Law of Photochemistry (the First Law) states that light must be absorbed for photochemical reactions to occur. If light of a particular wavelength is not absorbed, no photobiological changes will be observed, regardless of exposure duration. Some outcomes reported in studies using red light or low-level laser devices may be limited by this principle.

Source: https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/photchem.htm

Wavelength is a primary factor influencing how light may interact with tissue. Each wavelength exhibits different absorption characteristics. Red and visible light, as shorter wavelengths, tend to be absorbed at or near the surface of the skin.

On the electromagnetic radiation spectrum, infrared (IR; non-visible) wavelengths in the 780–1400 nm range are longer and may be transmitted with a higher percentage of energy reaching further into materials, including biological tissues, under certain conditions.

Combining red light (short) wavelengths with one or more infrared (long) wavelengths is commonly referred to as Photobiomodulation Therapy (PBMT), a method used in various wellness and therapeutic settings.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4390214/

Photobiomodulation Therapy is a newer term applied to light therapy. The term refers to the use of light to produce photochemical effects in cells or tissues. “Photo” refers to light; “Bio” refers to life; and “Modulation” refers to a change in response.

Summary: Red light alone may be suited for applications involving superficial skin interaction. Combining red light with infrared wavelengths may result in broader tissue interaction depending on the wavelength and target. Different wavelengths have different levels of absorption, and using multiple wavelengths may influence how broadly light is distributed and absorbed.

Key #3: Optimize Treatment Dosages

Optimizing treatment parameters is an important consideration when using photobiomodulation (PBM) devices. Dosage can refer to the combination of wavelength, power levels, treatment distance, and exposure time. While wavelength is related to how light travels through tissue, power affects how much light is delivered at a given depth. When reported outcomes are inconsistent, it may be due to factors such as insufficient light energy, short treatment durations, or use of equipment with limited output. Dosage is typically described as the energy delivered per unit area (joules per square centimeter, or J/cm²). With PBM devices, irradiance levels can vary depending on treatment distance, which may also influence measured outputs during device testing.

Some manufacturers may base their usage recommendations on the technical limitations of their devices. For instance, if a device does not emit certain wavelengths, it may be stated that those wavelengths are unnecessary. Similarly, devices with limited power may include cautions about “over-dosing” or “too much light energy” being potentially harmful.

The Arndt-Schulz law, also referred to as the biphasic dose response, is sometimes cited to suggest that higher doses may inhibit rather than support certain processes. However, this concept is not universally accepted as a biological law and does not originate from fundamental principles related to light or cellular processes. Applying it broadly to light-based applications lacks consistent validation.

Much of the available light therapy research exploring treatment parameters has been conducted in laboratory settings (in vitro), rather than in human clinical environments (in vivo). Laboratory conditions allow for precise measurement and control, and some studies have noted optimal dose ranges for cellular activity. These results are often discussed in the context of "hormesis," a term used to describe dose-response relationships where a substance may have differing effects depending on its concentration. Applying this concept to light, particularly in the context of human use, remains a subject of ongoing discussion and is not conclusively established.

Historical data from laboratory and animal models have reported varying effects from different light doses. For example, early studies from the 1960s using a ruby laser at doses from 0.05 to 4.0 J/cm² observed measurable outcomes in specific models. Later literature reviews have cataloged a range of parameters used in red and near-infrared light studies. However, it is important to note that these findings in preclinical models may not directly translate to human outcomes and are not substitutes for clinical evidence.

In the past, some clinical applications used dosage levels established in early research without adjusting for differences in tissue depth or treatment goals. This sometimes resulted in inconclusive or negative findings. These outcomes may have been due to mismatched treatment parameters for the intended application and not necessarily reflective of the technology's potential under appropriately defined conditions.

Summary: Treatment parameters—including wavelength, power, time, and distance—should be carefully considered when using photobiomodulation devices. Devices that allow for variation in these parameters may offer greater flexibility. Users should consult manufacturer guidelines and reference materials to determine appropriate configurations. No claims are made regarding clinical outcomes or efficacy, and all statements should be considered informational only.

Key #4: Full-Body Light Exposure Considerations

In Photobiomodulation Therapy (PBMT), some users and practitioners prefer systems that allow light exposure to larger surface areas of the body simultaneously. This approach can support efficient energy delivery within a session, depending on the design and output of the device being used.

Many light therapy devices utilize flat panel designs to target specific areas of the body. While some panels may be several feet in length, they typically deliver light to one side of the body at a time. Full-body systems that use a 360-degree configuration may offer a different form factor and light delivery method, which some users consider beneficial for reducing the need to reposition the body during a session. However, whether or how the body responds differently to full-body versus sectional exposure has not been universally established.

There are certain technical limitations inherent in flat panel systems, even when modular designs are used to link panels together. These limitations can include the number of light-emitting diodes (LEDs) that can be integrated, the ability to manage heat output, and available space to accommodate multiple wavelengths or larger diodes. Increasing power output typically requires larger diodes or more densely packed arrays, which also increases thermal output—requiring adequate cooling systems that may not be feasible in thinner or flat-panel designs.

Summary: Full-body PBMT systems may offer a different method of light delivery than sectional panel systems. The choice between system types often depends on user preference, treatment goals, and the technical specifications of the device.

Key #5: Understanding the Role of Pulsing

Photobiomodulation (PBM) devices may operate in different modes, including continuous wave or pulsed emission. Continuous wave emission delivers uninterrupted light energy, which requires technology capable of sustaining output without overheating or component failure.

Pulsed operation refers to light delivery that is not continuous—light energy is emitted in pulses of specified duration and at selected repetition rates. The terms pulsing and frequency are often used interchangeably in this context to describe the periodic interruption of energy delivery. In PBM, frequency typically refers to the pulse frequency of the device, measured in hertz (Hz), with 1 Hz indicating one pulse per second. A chopped beam is a continuous beam that is electronically or mechanically switched on and off. During “on” intervals, the output may be similar to continuous mode, though the average output power over time is lower due to the off periods.

The ability to select from various pulse frequencies can provide flexibility in device settings. Factors such as intended application area or session parameters may influence the choice of frequency.

Some devices offer pulsed settings but operate at limited power levels or with only one wavelength. In these cases, variations in settings may not produce significant differences in light distribution or dosage. Research continues in the area of combining higher output power and multi-wavelength designs with pulse modulation features.

Summary: The use of pulsed frequencies in PBM devices is an area of ongoing interest, particularly in conjunction with higher power and multi-wavelength configurations.

Products

It's now possible to use red light technology at home with the availability of advanced light-based devices.

One example is a light bed called TheraLight 360. TheraLight is marketed as a high-output commercial system for both consumer and professional use. It does not require a healthcare license to operate. This light bed (also referred to as a pod or capsule) offers approximately 10–15 minute sessions and features a 360° light exposure design. It includes four wavelengths (one red and three near-infrared) with adjustable frequency settings and power levels, controlled via a wireless tablet.

According to the manufacturer, TheraLight 360 is designed for general wellness applications and is also marketed for certain uses as a medical device when appropriate regulatory clearance has been obtained.

• Muscle relaxation and relief from muscle spasms
• Temporary treatment of minor muscle and joint discomfort
• Temporary relief of minor pain and stiffness associated with arthritis
• Temporarily Increase local blood circulation

Additional Resources

Challenge with Laser Studies: High Placebo Effect for Light and Lasers

Some individuals who receive light or laser therapy may report initial subjective improvement. However, these outcomes are not always reproducible and may be influenced by placebo effects.

Source:
https://www.ncbi.nlm.nih.gov/pubmed/16571371

Applications for Light and Laser Treatments Outside of Red Light Therapy

Cancer

There are established applications for lasers and light-based technologies in oncology settings. These uses typically involve specific technologies that are distinct from general red light therapy devices and are subject to FDA clearance for designated indications.

Low-Level Therapy Lasers

Low-level therapy lasers have been studied in certain clinical settings, such as for oropharyngeal mucositis associated with oncology care. These devices utilize infrared wavelengths and are investigated for non-invasive applications.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6122283/

Surgical Lasers

Surgical lasers are medical instruments that may be used in place of traditional surgical tools for cutting or removing tissue. They may offer greater precision and result in different post-procedure responses compared to conventional methods.

Source: https://www.cancer.org/cancer/managing-cancer/treatment-types/lasers-in-cancer-treatment.html

Photodynamic Therapy (PDT)

Photodynamic therapy combines light exposure with a photosensitizing agent. The agent is activated by a specific wavelength of light, often delivered by a laser. Once activated, the agent may have cytotoxic effects on targeted tissues. PDT has been studied for use in certain cancers and other conditions.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3572346/

Psoriasis

Lasers and light-based devices have been studied for various dermatological conditions, including psoriasis, vitiligo, and eczema. These technologies use specific wavelengths of light and different mechanisms of action.

UVA and UVB Devices

Multiple forms of light-based technologies have been explored in clinical and academic settings for dermatologic use. These include ultraviolet B (UVB), psoralen ultraviolet A (PUVA), pulsed dye laser (PDL), photodynamic therapy (PDT), intense pulsed light (IPL), and light-emitting diodes (LED). Psoriasis is a chronic autoimmune skin condition. Over the past several decades, phototherapy has been investigated for its potential in managing stable psoriatic lesions on areas such as the trunk, scalp, arms, legs, and in some cases, partial nail involvement.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5756569/

Excimer Lasers

Excimer lasers deliver a concentrated ultraviolet B (UVB) light at a wavelength of 308 nanometers to targeted areas of the skin. This type of delivery is designed to limit light exposure to unaffected skin. Excimer lasers have been evaluated in research and clinical use for mild-to-moderate psoriasis. In some clinical settings, individuals have received excimer laser treatments approximately twice a week over a course of 4 to 10 sessions.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5683125/

How Light May Relate to Mood, Sleep, and Travel Fatigue

Full Spectrum Lighting

Light-emitting devices have been studied in connection with Seasonal Affective Disorder (SAD), circadian rhythm disruptions, and certain sleep-related conditions. These devices may include light boxes that emit up to 10,000 lux (Full Spectrum Lighting) at a specific distance, or lower-intensity light sources focused on the blue (460nm) to green (525nm) wavelengths of the visible spectrum.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6746555/

Neonatal Jaundice (Postnatal Jaundice)
Blue Light: Fluorescent, LED, or Fiberoptic Systems

Phototherapy using blue light has been evaluated in clinical settings for its ability to interact with bilirubin, a compound involved in cases of neonatal jaundice. Bilirubin exhibits its highest light absorption within the 460–490nm range. Devices utilizing this range of blue light—including fluorescent bulbs, LEDs, or fiberoptic wraps—have been used in healthcare environments under professional supervision.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440981/

The History of Light and Its Applications: From Ancient Practices to Modern Developments

Light has been acknowledged as a natural source of energy since ancient times. Historical records indicate that civilizations such as the Greeks, Romans, and Egyptians engaged in sun exposure practices, often referred to as heliotherapy. In the 17th century, Sir Isaac Newton identified the visible spectrum of light by separating white light with a prism. In 1917, Albert Einstein introduced the theory of stimulated emission, which later became the foundation for the development of lasers—short for “Light Amplification by Stimulated Emission of Radiation.”

Throughout the 1940s and 1950s, engineers and physicists explored practical applications of stimulated emission. These efforts led to the creation of the first operational laser in 1960. In the late 1960s, Hungarian physician Endre Mester conducted research involving low-intensity laser exposure in animal models, which led to further investigations into potential biological effects.

In the 1990s, the U.S. Food and Drug Administration (FDA) cleared the use of Light Emitting Diode (LED) pads for specific therapeutic indications. Subsequent FDA clearances followed for Class III therapeutic lasers in 2002 and Class IV lasers in 2003, each for specified uses as reviewed and authorized by the agency.

Today, light-based technologies are used across a variety of regulated medical applications, including diagnostics, surgical tools, and certain rehabilitative and aesthetic procedures. A deeper understanding of the science of light continues to inform its role in medical device innovation.

Source: https://link.springer.com/chapter/10.1007/978-3-319-31903-2_1

The Science of Light

In physics, electromagnetic radiation refers to a form of energy that travels through space as a combination of electric and magnetic fields. These waves are categorized by wavelength and include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays within the electromagnetic spectrum.

Light consists of photons, which are elementary particles representing discrete packets of electromagnetic energy. These are classified on the electromagnetic spectrum. Light travels at a constant speed—approximately 186,282 miles per second—and exhibits wave-like behavior as it moves. The key characteristic that distinguishes different types of electromagnetic radiation is wavelength, measured in nanometers (nm).

Wavelength determines various optical properties, such as color in the visible spectrum. The visible spectrum, which is only a small portion of the electromagnetic spectrum, ranges from approximately 380nm to 750nm. Just beyond the visible range lies infrared radiation, spanning from about 700nm to 1 millimeter. Although infrared light is not visible to the human eye, it can be detected using specific tools such as infrared cameras.

Source: https://www.nasa.gov/directorates/somd/space-communications-navigation-program/spectrum-overview/

How Light Interacts with the Human Body: Photochemical Mechanisms

Light can interact with biological tissue in several ways, including:

• Photothermal or Photoablation – This interaction involves the use of heat to vaporize tissue and is associated with technologies such as surgical lasers and certain hair removal lasers.
• Photomechanical or Photoacoustic – These mechanisms disrupt molecular bonds through mechanical forces and are used in applications such as tattoo removal lasers.
• Photochemical, Photodynamic, or Photobiomodulation – This form of interaction involves light-induced chemical reactions in targeted cells. It is associated with certain types of lasers and light-emitting devices.

Light, when emitted at specific wavelengths and frequencies, may stimulate cellular processes. This interaction has been observed in various biological contexts and is the subject of ongoing research. The use of light-emitting devices is based on the principle that light may influence cellular activity.

Source: https://scialert.net/fulltextmobile/?doi=ijp.2011.149.160

Photobiomodulation (PBMT): The Correct Term for Red Light Therapy

Photobiomodulation Therapy (PBMT) refers to the use of specific wavelengths of red and near-infrared light applied to tissue. PBMT devices have been studied for their potential effects on tissue exposed to various stressors, including physical strain and environmental factors. Some research suggests that PBMT may influence biological processes such as inflammatory responses, cellular activity, and circulation. In controlled settings, PBMT has been evaluated for its effects on muscle recovery, joint mobility, and wound environments. Certain studies have observed changes in exercise duration and selected biomarkers—such as lactate, creatine kinase, and C-reactive protein (CRP)—following light exposure. PBMT is generally well-tolerated, and no significant adverse effects have been widely reported in published literature. The biological mechanisms involved are under active investigation at the molecular, cellular, and tissue levels.

Photobiomodulation

“PHOTO” means light. “BIO” means life. “MODULATION” means change.

According to the North American Association of Photobiomodulation Therapy (NAALT), Photobiomodulation Therapy is described as:

A form of light application that utilizes non-ionizing light sources, including LASERS, LEDs, and broad-band light, in the visible and infrared spectrum. It is a non-thermal process involving endogenous chromophores that may elicit photophysical and photochemical responses at various biological scales.

Some sources suggest this process may be associated with outcomes such as temporary relief of minor aches, relaxation of muscles, and local circulation changes.

Source: https://www.naalt.org