What is photobiomodulation? Photobiomodulation (PBM) is the therapeutic use of specific light wavelengths—mainly red (630–660 nm) and near-infrared (810–850 nm)—to induce biological effects at the cellular level. It is not ordinary light exposure. Instead, it relies on targeted wavelengths acting on specific biological targets—from mitochondria to soft tissues, joints, and muscles.
Table of contents
- What phototherapy actually refers to
- How photobiomodulation works
- What happens in cells during phototherapy
- Why wavelength matters
- Different types of phototherapy and how they are used
- Where phototherapy is actually used
- What current research actually shows
- How safe is phototherapy
- Getting started: what to look for first
- Frequently Asked Questions (FAQ)
- What to remember
- Scientific references
What phototherapy actually refers to
Phototherapy uses specific light wavelengths to influence cell and tissue responses. Different wavelengths are used for different purposes—some for treating skin inflammation, others for acne, and still others in conditions where deeper tissue repair is being investigated.
Phototherapy is not the same as ordinary sun exposure. It is controlled—the wavelength, intensity, and exposure time are set according to the therapeutic goal. In clinical application, ultraviolet light is most commonly used to treat conditions such as psoriasis, eczema, and vitiligo. Home devices typically do not emit UV radiation—they use red or blue LED light for acne treatment or general skin issues.
The idea itself is not new. Niels Finsen received the Nobel Prize in 1903 for treating skin diseases with light. What has changed, however, is how these therapies are targeted. Today, phototherapy includes both medical UV protocols and LED-based methods such as photobiomodulation.
Is phototherapy the same as light therapy?
Usually, yes. In everyday use, the terms "phototherapy" and "light therapy" mean the same thing. Phototherapy is a more precise term and commonly used in medicine—it refers to specific wavelengths used for a specific purpose. Light therapy has a broader scope and can also include lamps for mood improvement or home-use devices.
Is red light therapy a type of phototherapy?
Yes. Red light therapy is a part of phototherapy. It uses red wavelengths, typically ranging from 630 to 660 nm. Sometimes, when deeper tissues are involved, near-infrared (NIR) is also included. Most research on this technique focuses on cellular energy production, inflammation, and tissue repair.
How photobiomodulation works
Photobiomodulation works by using specific light wavelengths to interact with the body's cells and tissues. These wavelengths are measured in nanometers and determine the depth of light penetration into tissues. Shorter wavelengths act closer to the skin's surface, while longer wavelengths reach deeper layers—muscles, joints, and bones.
Ultraviolet light is used in dermatology because it acts at the skin level and can influence immune system activity in conditions like psoriasis. Red and near-infrared light are studied more for their role in inflammation, cellular activity, and tissue regeneration.
Photobiomodulation refers to treatments using LEDs that aim to influence cellular function, rather than remove or damage tissues. Lasers are focused and used for cutting or resurfacing—photobiomodulation has lower intensity and acts more gradually, supporting natural biological processes.
More details on the interaction of light with cells can be found on our page dedicated to the mechanism of action of red light therapy.
What happens in cells during phototherapy
Cells do not react to all light in the same way. Certain molecules, called chromophores, absorb specific wavelengths. This interaction is responsible for most of the biological effects observed in phototherapy.
In red and near-infrared applications, attention often focuses on cytochrome c oxidase—an enzyme associated with mitochondrial activity. It is studied in the context of energy management and cell signaling, particularly concerning ATP production—the body's basic energy currency. Simply put, this involves changes in how cells use energy, support for repair processes, changes in inflammatory signaling, and—in some cases—changes in local blood circulation.
Not all of these pathways are fully mapped. Some mechanisms are confirmed by consistent research results, others are still the subject of active scientific investigation.
UV phototherapy works differently—it is used in dermatology to slow down the rapid renewal of skin cells and regulate immune system activity. This difference partly explains its effectiveness in treating conditions like psoriasis, as well as the need to control cumulative exposure under medical supervision.
Why wavelength matters: not all light works the same way
Light does not behave the same across the entire electromagnetic spectrum. Wavelength changes both the distance it travels through tissues and what it biologically interacts with. The therapeutic window of light falls within the 400–900 nm range—from visible light to near-infrared.
- Blue light (415–450 nm) — remains close to the skin's surface (epidermis), primarily used in the context of acne and skin bacteria
- Red light (630–660 nm) — penetrates the dermis, discussed in the context of inflammation, collagen, and general skin processes
- Near-infrared light (810–850 nm) — penetrates deeper tissues (muscles, joints, bones), seen in the context of regeneration and repair
- UV light (200–400 nm) — acts at the epidermal level, clinically used to treat immune-mediated skin diseases, requires medical supervision
Although it's all "light," the effects are not interchangeable. Changing the wavelength changes the actual action of the treatment—both penetration depth and biological target.
Different types of phototherapy and how they are used
UV Phototherapy (UVA, UVB, Narrowband UVB)
UV phototherapy uses ultraviolet light in several forms: UVA (320–400 nm), UVB (280–320 nm), and narrowband UVB (311–313 nm). It is typically used in dermatology clinics to treat psoriasis, eczema, or vitiligo. Sessions are spaced out—UV exposure is cumulative and requires careful dose control. Red light therapy differs in both its mechanism of action and safety profile.
Red Light Therapy (630–660 nm)
Red light therapy is the non-UV part of phototherapy, typically using wavelengths from 630 to 660 nm. You encounter its discussion in the context of inflammation, healing, and general tissue support, often within the broader concept of photobiomodulation.
Blue Light Therapy (415–450 nm)
Blue light therapy takes place close to the skin's surface and is usually used to treat acne. Its role is related to compounds produced by acne-causing bacteria—they react to blue wavelengths.
Near-Infrared Therapy (810–850 nm)
Near-infrared (NIR) is a band of radiation just beyond visible red light. It is used within muscles, joints, and deeper tissues. Lumaflex devices use precisely selected wavelengths of 660 nm and 850 nm simultaneously, maximizing the therapeutic effect at both levels.
Bright Light Therapy
Bright light therapy is more commonly used to improve circadian rhythm and mood. It is most often observed in the context of seasonal affective disorder and sleep disorders.
Combined Devices and Full Spectrum
Some devices combine more than one wavelength in a single unit. Efficiency, wavelength accuracy, and emission consistency typically matter more than the sheer number of diodes. Check the comparison of Lumaflex devices to see the differences between models.
Where phototherapy is actually used
Phototherapy has several applications, depending on the type of light. In dermatology, it is used to treat conditions such as psoriasis, eczema, vitiligo, and acne.
- wound and soft tissue healing
- collagen and skin texture
- hyperpigmentation
- joint and muscle regeneration after physical exertion
- hair growth and scalp health
- neurological and cognitive applications
- veterinary medicine — sport horses, dogs, cats
What current research actually shows
The effectiveness of phototherapy varies depending on the method. Detailed scientific foundations can be found on our Our Science page.
Where the evidence is already strong
Narrowband UVB for psoriasis treatment is one of the most popular forms of phototherapy, used for decades in clinical practice. Blue light therapy for acne treatment also has solid scientific foundations.
Where evidence for red light and NIR is still accumulating
Red light and near-infrared therapy are the subject of increasing research. Studies suggest that these wavelengths can support mitochondrial activity and ATP production, influence inflammatory signaling pathways, and aid in skin and soft tissue regeneration processes. However, results vary greatly depending on the type of device, wavelengths, intensity, and duration of therapy.
Where science is still evolving
Phototherapy is still an active field of research. New areas include: hair and scalp health, neurological and cognitive applications, long-term home device use, and standardized dosing protocols.
Clinical vs. Preclinical Research: Why the Difference Matters
Preclinical research includes laboratory studies and animal studies. Clinical research involves human studies and provides more direct insight into real-world outcomes. Mechanistic findings do not always translate directly into consistent clinical outcomes in humans.
How safe is phototherapy
UV and non-UV Phototherapy — a key distinction
UV phototherapy has medical value but involves cumulative exposure to ultraviolet radiation—it must be used under medical supervision. Red, blue, and near-infrared LED phototherapy does not use UV radiation and generally carries a lower risk when used as directed by the manufacturer.
Common side effects
Even low-risk forms of phototherapy can cause mild side effects: temporary redness, warmth, dryness, and sensitivity in the treated area.
Who should exercise particular caution
Particular caution should be exercised by individuals taking photosensitizing medications, those with a history of skin cancer, pregnant women, or those with implanted pacemakers. In case of diagnosed skin diseases, consult a dermatologist before starting any form of phototherapy.
Getting started: what to look for first
- Wavelength — 660 nm for skin and superficial tissues, 850 nm for deeper muscles and joints
- Energy dose (fluence) — optimal range 4–50 J/cm² depending on the indication; too low a dose is ineffective, too high can paradoxically inhibit effects (Arndt-Schulz effect)
- Exposure time — typical sessions last 5 to 20 minutes per area
- Device quality — wavelength accuracy and emission consistency are more important than the number of diodes
- Regularity — PBM effects are cumulative and require systematic use
Lumaflex devices are designed for maximum clinical effectiveness with ease of use. The flexible, portable design allows precise application of the panel to any body part. If you want to test the device before purchase, use our rental service—14 days of testing.
Also check out the Why Lumaflex page to learn more about what sets our devices apart in the market.
Frequently Asked Questions (FAQ)
What is photobiomodulation in short?
Photobiomodulation is the therapeutic use of specific light wavelengths to induce biological effects in the body. Different wavelengths serve different purposes—UV light is used clinically to treat skin conditions, blue light for acne, and red or near-infrared light supports cellular repair and inflammatory balance.
What is phototherapy used for?
Phototherapy is used in many applications, including psoriasis, eczema, vitiligo, acne, and seasonal affective disorder. Research is also ongoing into its use in wound healing, skin support, joint and muscle regeneration, and hair growth.
Is phototherapy the same as red light therapy?
No. Red light therapy is one type of phototherapy. The broader term includes UV phototherapy, blue light therapy, bright light therapy, and near-infrared therapy. Each of these modalities works at a different wavelength and has different clinical applications.
Is phototherapy safe?
It depends on the type. UV phototherapy requires medical supervision. LED phototherapy generally carries a lower risk when used correctly. Individuals taking photosensitizing medications or with a history of skin cancer should consult a doctor.
Can phototherapy be used at home?
Some forms can. Home phototherapy typically relies on LEDs. If you want to test an LED device before purchasing, use our Lumaflex rental service.
How does photobiomodulation differ from laser therapy?
Photobiomodulation uses controlled LED light to influence biological processes, usually without damaging tissues. Laser therapy uses more concentrated, higher-intensity light and is often used for cutting, ablation, or resurfacing. PBM works gradually and supports natural regenerative processes.
Does photobiomodulation work on animals?
Yes. PBM is also used in veterinary medicine—especially for sport horses, dogs, and cats. Lumaflex offers dedicated LED panel kits for horses.
How long does a photobiomodulation session last?
Typical sessions last 5 to 20 minutes per body area. The effects are cumulative—regular use yields better results than single long sessions.
What to remember
- Photobiomodulation involves the therapeutic use of light wavelengths to affect biological processes at the cellular level.
- It encompasses many modalities: UV phototherapy, red light therapy, near-infrared therapy, and bright light therapy.
- Different wavelengths penetrate to different depths and act through different biological mechanisms.
- UV phototherapy requires medical supervision.
- Increasing scientific evidence supports the effectiveness of LED phototherapy, but results vary depending on the device and protocol.
- Home LED phototherapy is not equivalent to clinical phototherapy for diagnosed conditions.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Clinical phototherapy, especially UV-based therapy, requires medical supervision. If you have a diagnosed skin condition or persistent symptoms, consult a qualified dermatologist or physician before starting any form of phototherapy.
Scientific References
Almutawa, F., et al. (2013). A systematic review of UV-based psoriasis therapies. American Journal of Clinical Dermatology, 14(2), 87–109.
Ash, C., et al. (2015). A randomized controlled study of blue light therapy for the treatment of acne vulgaris. Journal of Cosmetic and Laser Therapy, 17(5), 259–264.
Avci, P., et al. (2013). Low-level laser (light) therapy (LLLT) in the skin: stimulation, healing, restoration. Seminars in Cutaneous Medicine and Surgery, 32(1), 41–52.
Hamblin, M. R. (2017). Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophysics, 4(3), 337–361.
Huang, Y. Y., et al. (2009). Biphasic dose response in low-level light therapy. Dose-Response, 7(4), 358–383.
Papageorgiou, P., et al. (2000). Phototherapy with blue and red light in the treatment of acne vulgaris. British Journal of Dermatology, 142(5), 973–978.
Yadav, A., et al. (2017). Effect of low-level laser therapy on wound healing. Photodermatology, Photoimmunology & Photomedicine, 33(4), 181–192.
Taha, N., et al. (2024). The impact of low-level laser therapy on wound healing and pain management. Cureus, 16(10), e72542.
