What Is Red Light Therapy? A Practical Guide to Photobiomodulation
Red light therapy is everywhere — in clinics, recovery centres, beauty devices and home wellness products. But the science is more specific than simply “shining red light” on the body. Photobiomodulation uses particular wavelengths and doses of red or near-infrared light to influence biological activity in tissue.
What Is Red Light Therapy?
Red light therapy is a commonly used name for photobiomodulation, often shortened to PBM.
PBM uses specific wavelengths of visible red light and near-infrared light delivered at controlled intensities and doses. You may also see terms such as low-level light therapy or low-level laser therapy used in the research.
The aim is not to heat or damage tissue. Instead, photons are absorbed by light-sensitive molecules within cells, triggering biological responses that researchers are investigating across a wide range of applications.
“Red light therapy” is a broad consumer term. Photobiomodulation is more precise. The wavelength, power, dose, treatment area, device, timing and condition being treated can all influence the biological effect.
How Can Light Affect a Cell?
The leading mechanism involves absorption of red and near-infrared photons by cellular chromophores, including an enzyme in mitochondria called cytochrome c oxidase.
Mitochondria are involved in producing ATP — the energy currency used by cells. Photobiomodulation appears capable of influencing mitochondrial activity and several downstream signalling pathways.
The process is more complex than simply “boosting ATP”. Research also describes changes in reactive oxygen species signalling, nitric oxide, calcium signalling and gene expression.
Photon Absorption
Red and near-infrared photons can be absorbed by cellular photoreceptors, including mitochondrial cytochrome c oxidase.
Mitochondrial Activity
PBM may influence mitochondrial membrane potential, electron transport and ATP-related cellular energy processes.
Cell Signalling
Downstream signalling can involve nitric oxide, calcium, reactive oxygen species and transcription pathways.
Biological Response
These signals can influence processes such as cell migration, proliferation, inflammatory signalling and tissue response.
Why Wavelength Matters
Not every red-light device delivers the same type of light. Different wavelengths interact differently with tissue, and this is one reason results from one device or protocol cannot automatically be applied to another.
Typically around 620–700 nm
Visible red wavelengths are commonly used in photobiomodulation applications involving skin and more superficial tissues.
Typically above 700 nm
Near-infrared wavelengths are invisible to the eye and are often selected where greater tissue penetration is required.
The right wavelength depends on the tissue and outcome being targeted. PBM is dose-dependent, and different applications require different treatment parameters.
The Evidence Depends on the Application
Photobiomodulation has been studied for decades, but saying “red light therapy is clinically proven” is too broad.
There is no single PBM outcome. Research differs substantially according to the condition, wavelength, device, dose and treatment schedule.
Skin & Dermatology
PBM has been investigated in areas including skin ageing, inflammatory skin conditions, wound response and dermatological recovery. Evidence varies by indication and protocol.
Pain & Musculoskeletal Health
Research includes musculoskeletal pain, joints, tendons and soft-tissue applications. Results are not uniform across every condition or treatment protocol.
Exercise & Recovery
PBM has been studied in exercise performance and muscle recovery. Reviews suggest potential in some areas, but protocol variability remains a major issue.
Neurological Research
Red and near-infrared light are also being investigated in neurological and brain-related research, but many applications remain experimental or emerging.
PBM & Exercise Recovery
Exercise recovery is a useful example of why broad claims about red light therapy can be misleading.
Whole-body PBM has become increasingly popular in sports and recovery settings, but a 2025 systematic review noted that protocols and methodologies varied considerably between studies.
Whole-Body Photobiomodulation & Exercise
Researchers reviewed whole-body PBM in relation to exercise performance and recovery. The field showed potential, but differences in devices, wavelengths, doses and study methods made firm conclusions difficult.
Muscle Recovery
Another recent systematic review assessed photobiomodulation alongside other physical recovery interventions for muscle recovery. The findings add to the evidence base, but again highlight that treatment type and protocol matter.
View the Research on PubMed →Dose Matters as Much as the Colour of the Light
A red-looking device is not enough to tell you whether it is delivering an appropriate photobiomodulation treatment.
Researchers describe PBM as having wavelength- and dose-dependent effects. In practical terms, several variables matter.
Determines which light is being delivered and how it interacts with tissue.
Describes the amount of optical power reaching a given area.
Depends on both intensity and treatment time. Longer is not automatically better.
A small local laser treatment and a large-area light device are not equivalent simply because both use red or near-infrared light.
Treatment schedules vary considerably between research protocols and intended applications.
Is a Laser Better Than an LED Panel?
Both LEDs and low-level lasers can be used for photobiomodulation. They deliver light differently, and the appropriate option depends on the treatment objective.
A targeted laser may be selected for a focused area, whereas larger LED or multi-diode systems can cover a broader treatment area.
The important comparison is not simply “laser versus LED”. It is the combination of wavelength, power, dose, treatment area, tissue depth and intended biological outcome.
Why this matters when buying a home device
Consumer products vary substantially. A product being red, near-infrared or marketed as “medical grade” does not by itself establish that it matches the protocol used in a published study.
Is Red Light Therapy Safe?
PBM is generally described as a non-invasive light therapy and does not work by heating or deliberately damaging tissue.
That said, appropriate use still matters. Devices can differ in power and wavelength, and eye protection or other precautions may be relevant depending on the equipment and treatment area.
People receiving medical treatment, taking photosensitising medications, managing significant health conditions or considering treatment over a suspicious skin lesion should seek appropriate professional advice.
“Non-invasive” does not mean “use anything, at any dose”.
The aim should be an appropriate treatment for a defined purpose, not simply the maximum light exposure available.
Looking for Photobiomodulation Treatment in Ireland?
ReWell's core specialist area is Hyperbaric Oxygen Therapy. For dedicated red light and laser-based photobiomodulation, we recommend our sister clinic, Luma Health.
Luma specialises in photobiomodulation and light-based therapy, including targeted low-level laser therapy and broader-area GigaLaser treatment.
Its team works across areas including recovery, pain, women's health and fertility support, with treatments delivered through dedicated PBM services.
Explore Red Light Therapy at Luma Health
If red light therapy is the treatment you are specifically interested in, Luma is the best place to learn more about the technology, treatment options and current clinic services.
Visit Luma Health Explore Luma PhotobiomodulationRed Light Therapy & HBOT Are Not the Same Thing
Both technologies appear in recovery and wellness settings, but they work through fundamentally different physical mechanisms.
Uses Light
Red and near-infrared photons interact with cellular photoreceptors and influence mitochondrial and downstream signalling pathways.
Uses Pressure + Oxygen
Hyperbaric Oxygen Therapy increases ambient pressure and oxygen exposure, increasing the amount of oxygen dissolved in blood plasma during treatment.
One should not be described as a substitute for the other. Whether either technology is relevant depends on the person's goal, condition and individual circumstances.
Learn More
References
- Hamblin MR. Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation. Photochem Photobiol. 2018. PubMed
- Hamblin MR. Proposed Mechanisms of Photobiomodulation or Low-Level Light Therapy. PubMed
- Photobiomodulation CME Part I: Overview and Mechanism of Action. 2024. PubMed
- Álvarez-Martínez M, Borden G. A systematic review on whole-body photobiomodulation for exercise performance and recovery. Lasers Med Sci. 2025. PubMed
- Canez MS, et al. Effects of photobiomodulation, intermittent pneumatic compression and neuromuscular electrical stimulation on muscle recovery: systematic review with meta-analysis. 2025. PubMed
Red Light Therapy FAQs
What is red light therapy?
Red light therapy is a common name for photobiomodulation, a non-invasive treatment that uses specific red and near-infrared wavelengths to influence biological activity in cells and tissues.
Is red light therapy the same as photobiomodulation?
The terms are often used interchangeably, although photobiomodulation is the more precise scientific term. PBM can include both visible red and near-infrared wavelengths and can be delivered by LEDs or low-level lasers.
How does red light therapy work?
One of the main proposed mechanisms involves absorption of light by mitochondrial cytochrome c oxidase. This can influence mitochondrial activity and downstream cellular signalling involving ATP, nitric oxide, reactive oxygen species and calcium.
Does red light therapy increase ATP?
PBM can influence mitochondrial bioenergetics and ATP-related processes, but describing the treatment simply as an “ATP booster” leaves out much of the biology. Dose, wavelength and the state of the tissue all influence the response.
Is near-infrared light better than red light?
Not automatically. Near-infrared light generally penetrates tissue differently from visible red light, but the appropriate wavelength depends on the tissue, device and treatment objective.
Can I use a home red light device?
Home devices are widely available, but their wavelengths, irradiance, treatment area and dose can vary substantially. A consumer product should not be assumed to reproduce the protocol used in a clinical study simply because it emits red or near-infrared light.
Where can I access red light therapy in Ireland?
ReWell's sister clinic, Luma Health, specialises in photobiomodulation and light-based therapies in Ireland. You can learn more about its current services at Luma.ie .
Red Light Therapy Is More Than the Colour of the Light
Photobiomodulation is a genuine area of biomedical research with plausible cellular mechanisms and a growing evidence base across a range of applications.
But the category is broad. Different wavelengths, devices, doses and treatment protocols can produce different biological effects, and evidence from one application should not automatically be used to support another.
The useful question is therefore not simply: “Does red light therapy work?”
It is: “Which type of photobiomodulation, at what dose, for which outcome — and what does the evidence show for that particular use?”
Interested in Red Light or Laser Therapy?
Visit our sister clinic Luma Health to explore dedicated photobiomodulation, red light and laser-based treatments in Ireland.