In brief
Photobiomodulation exposes tissue to low-intensity red or near-infrared light to influence biological responses without burning skin. Outcome depends on wavelength, power, dose, time, distance and the area exposed. A suitable colour alone cannot guarantee a result.
The field of Photobiomodulation, or PBM, is sometimes called LED therapy when light-emitting diodes are used. It is increasingly seen in beauty and wellbeing routines, though face masks, panels and LED boots have very different designs.
The meaningful question is not only “does red light work?” but what wavelength and dose, which device and frequency, over which area and for what aim?
Eight essential pointers
- PBM mainly uses red and near-infrared light, not UV.
- LED therapy is not based on intense heat and should not be confused with an infrared sauna.
- Wavelength affects how light travels through tissue, but cannot predict results alone.
- The received dose depends on output, time, distance and actual coverage.
- Too little light may have no effect; excessive exposure is not automatically better.
- Skin research is encouraging, particularly on the face, but protocols vary.
- Clinical-device outcomes do not automatically apply to all home devices.
- Photosensitivity, photosensitising medicines or suspicious skin lesions require prior advice.
What is photobiomodulation?
It is the non-thermal use of visible red or near-infrared light to influence certain cellular responses. The aim is a controlled light signal, not the tissue destruction produced by some thermal lasers or procedures.
The term covers several technologies:
- light-emitting diodes, or LEDs;
- low-level lasers;
- light panels;
- face masks;
- wraparound devices for the body or legs.
These are not equivalent. A similar visible colour can be produced at very different outputs, angles, durations and light distributions.
Nor is PBM the same as photodynamic therapy. Photodynamic therapy combines light with a photosensitising substance to produce a specific therapeutic reaction; ordinary PBM does not use that principle.
How do red light, infrared, UV and heat differ?
Red light, near-infrared, ultraviolet and heat refer to distinct phenomena. A PBM LED boot is designed neither to tan skin nor to raise its temperature substantially.
| Technology | Main characteristic | What to know |
|---|---|---|
| Red light | Visible light, often used around 620–700 nm | Studied in relation to skin quality and some visible signs of ageing |
| Near-infrared | Light beyond visible red, sometimes barely perceptible | Generally penetrates more deeply at comparable settings |
| Ultraviolet | Radiation beyond violet in the spectrum | Can tan and damage skin; different from standard red-light PBM |
| Infrared heat | Technology principally intended to raise temperature | Not the same as low-intensity light exposure |
| Ablative or thermal laser | Concentrated energy with a controlled tissue effect | Different power, indications and supervision |
Our article Red light or heat: what differs for your legs? explores this distinction, particularly relevant if you are sensitive to heat.
How might PBM act on cells?
Researchers study how PBM may influence cellular signalling, energy metabolism and responses involving oxidative stress or inflammation. Exact mechanisms vary with wavelength, cell type, dose and tissue condition.
Mitochondria are often mentioned in explanations. They contribute to usable cellular energy. Certain cell components can absorb photons, temporarily influencing signalling pathways.
Investigated effects include:
- changes in ATP production;
- changes in nitric oxide;
- modulation of reactive oxygen species;
- activation of transcription factors;
- changes in inflammatory responses;
- influence on some repair processes.
This is a simplification. Light does not mechanically “recharge” every cell in the same way or guarantee automatic collagen production in every setting.
Which settings determine the effect of a session?
Wavelength, irradiance, duration, distance, total dose and coverage work together. Two devices both marked 660 nm may deliver very different exposures.
| Parameter | Simple definition | Why it matters |
|---|---|---|
| Wavelength | Position in the light spectrum, in nanometres | Influences absorption and tissue penetration |
| Irradiance | Light power received per surface area | Determines how quickly energy is delivered |
| Duration | Exposure time | Affects total dose, but longer is not always better |
| Distance | Space between LEDs and skin | Can significantly change actual intensity received |
| Angle and coverage | Distribution across the area | Affect evenness of exposure |
| Frequency | Number of sessions over time | Consistency is often needed to assess gradual changes |
LED count alone cannot tell you the dose. Many diodes can improve coverage, but their power, distribution and proximity to skin also matter.
What is a light dose in PBM?
It is the amount of energy received per surface area during a session. Time alone cannot calculate it: ten minutes under a lower-power device is not the same as ten minutes under a stronger one close to the skin.
Research often describes a biphasic dose response. In that model:
- too low a dose might have no measurable effect;
- an intermediate range may be more useful;
- excessive exposure may reduce benefit or cause discomfort.
This is why “longer” or “more powerful” is not automatically “more effective”. Follow your device's instructions for session time and frequency.
A wavelength is not a complete protocol
A label of 660 or 850 nm is not proof of effectiveness. Wavelength must sit alongside sensible output, dose, coverage, duration and frequency. Research outcomes can only be applied if the studied device and protocol are sufficiently similar.
What skin effects does current evidence support?
The more promising findings involve the appearance of some signs of skin ageing, texture, fine lines and dermal density. Studies are nevertheless often small, use different devices and mainly examine the face.
A 2023 trial reported improvements in several visible facial ageing measures after regular red-light sessions. A 2025 home-device study combining 630 and 850 nm light also reported changes in skin rejuvenation measures.
These results do not prove an LED boot will produce identical outcomes on thighs or calves. Facial and leg skin differ in thickness, sun exposure, blood supply and the concerns being addressed.
The most careful summary is:
Red and near-infrared PBM may support some measures of visible skin quality, but the extent of change depends greatly on device, area and protocol.
Does red light really stimulate collagen?
Some studies report changes consistent with increased dermal density or certain collagen markers. “Stimulates collagen” still needs context: any result is not immediate, uniform or guaranteed with every device.
Collagen is a family of proteins that helps structure the dermis. Its production changes with age and can be affected by sun, smoking, hormones and other factors.
A light routine may reasonably aim for:
- smoother-looking skin;
- more even texture;
- a more comfortable skin feeling;
- improved perceived firmness for some users.
PBM cannot mechanically tighten very loose skin or replace dermatological or surgical care when appropriate.
Can PBM reduce cellulite?
Evidence specific to cellulite is limited. It does not establish that red light removes fibrous bands or destroys fat cells. A change in skin texture may affect overall appearance without treating every cellulite mechanism.
Cellulite involves:
- fibrous bands;
- adipose tissue contours;
- dermal quality;
- skin laxity;
- lighting and body position.
LED therapy can sit within a skin-texture routine, but should not be marketed as permanently erasing dimpling.
Can PBM affect stretch marks, scars and spots?
Research explores PBM for healing and skin characteristics, but outcomes depend heavily on the mark's type, age and cause. An old white stretch mark, a recent scar and a pigmented spot do not involve the same process.
A new, irregular, changing or bleeding pigmented lesion needs examination before light exposure. LED therapy must never delay a dermatology appointment.
For assessed, stable marks, a routine may aim at a more even appearance or comfort; changes are gradual and variable.
Is photobiomodulation useful for legs?
Evidence specifically on leg skin is less abundant than that for faces. The practical appeal of a wraparound device is consistent exposure across a larger area at home.
An LED boot may be considered for:
- visible skin quality;
- skin laxity;
- uneven texture;
- some assessed marks or stretch marks;
- skin comfort.
It does not compress or mechanically drain the legs or replace pressotherapy boots. Read LED boots or pressotherapy boots: what differs? to compare.
Can you apply professional-device research to a home device?
Clinical or professional-device results cannot simply be transferred to a home device. Output, dose, distance, area and control of the protocol may differ substantially.
When assessing a study, check:
- wavelength;
- irradiance;
- dose per session;
- number of sessions;
- area treated;
- participants;
- how outcomes were measured;
- whether there was a control group.
Responsible brands distinguish published science from results directly demonstrated with their own device.
How to choose a home PBM device
Start with the area to cover, wavelengths, clear instructions, safety and brand transparency. LED count or “professional” wording alone cannot establish quality.
| Criterion | Question | Reassuring sign |
|---|---|---|
| Area | Does it actually cover the intended area? | A shape suited to face, legs or another target |
| Wavelengths | Are nanometre figures clearly stated? | Precise, consistent specifications |
| Protocol | Are time and frequency explained? | Clear instructions without pressure to overuse |
| Coverage | Is light evenly distributed? | Stable, comfortable fit |
| Precautions | Are contraindications visible? | Clear mention of photosensitivity, treatments and lesions |
| Claims | Does the brand distinguish appearance from treatment? | Nuanced results, identified sources and explicit limits |
Our complete Eclipse LED Therapy guide explores these criteria and how to read specifications.
What do Eclipse LED Therapy boots offer?
They expose leg skin to 660 nm red and 850 nm near-infrared light. The device includes 528 LEDs, five programmes and a stated routine of 10 to 20 minutes per leg, three to five times weekly.
These specifications describe Eclipse's device but do not guarantee the same result for every skin type.
The intended routine chiefly concerns:
- visible skin quality;
- texture;
- radiance;
- skin laxity;
- marks and stretch marks;
- skin comfort.
Eclipse LED boots cannot replace dermatological treatment, medical compression or a pressotherapy device.
The Eclipse approach
At Eclipse, we present PBM as a gradual light-based technology, not a miracle solution. Wavelength matters, but so do consistency, dose, coverage and safety. Reasonable goals primarily concern skin appearance and comfort.
What precautions matter before a session?
Low-intensity PBM is generally well tolerated but not suitable for every situation. Photosensitivity, photosensitising treatment, active skin disease or a suspicious lesion calls for professional advice.
Ask before use with:
- photosensitive epilepsy;
- photosensitising medicines or cosmetics;
- significant skin disease;
- a suspicious pigmented lesion;
- cancer treatment or recent history, according to your medical team;
- pregnancy;
- recent surgery;
- burned, infected or very irritated skin.
Use the device on clean, dry skin. Follow session length, and do not apply a potentially photosensitising product immediately beforehand.
How soon might you see a result?
Changes in skin appearance generally need weeks of regular use, rather than one session. Timing depends on your aim, skin, device and adherence to instructions.
A session may feel pleasant quickly. Texture, perceived firmness or marks may take longer to change and are not guaranteed.
To assess a routine:
- take photos in similar light and pose;
- avoid changing several treatments at once;
- follow the stated frequency;
- watch skin tolerance;
- think in terms of weeks.
Frequently asked questions about PBM
Are PBM and LED therapy the same?
LED therapy can be a form of PBM when it uses appropriate low-intensity red or near-infrared light. Not every LED use is an effective PBM protocol.
Does red light heat skin?
A device may feel mildly warm, but PBM is not intended to heat tissue intensely. Significant heating is a different approach.
Which wavelength is best?
There is no universal winner. Red and near-infrared light penetrate differently; usefulness depends on the target, output, dose and protocol.
Do more LEDs mean more effectiveness?
Not necessarily. Count speaks to potential density and coverage, not irradiance, dose or evenness of exposure.
Can PBM remove cellulite?
No evidence establishes that it destroys fat or fibrous bands. Some users may see a change in texture or skin appearance.
Can you use LED boots daily?
Follow your device's instructions. More sessions are not automatically better. Eclipse LED Therapy's stated routine is 10 to 20 minutes per leg, three to five times weekly.
What should you remember?
PBM is a credible light-based technology, but its effectiveness cannot be reduced to a colour or LED count. Consider wavelength, dose, device, area, consistency and evidence quality together.
- It uses relatively low-intensity red or near-infrared light.
- LED therapy does not use UV or rely on intense heat.
- Dose matters alongside wavelength.
- Excessive exposure is not automatically beneficial.
- Skin research is promising but varied.
- Evidence for legs is less extensive than for faces.
- Professional-device outcomes do not automatically apply to home products.
- PBM cannot replace dermatological diagnosis or treatment.
Sources, method and editorial transparency
This Eclipse guide summarises dermatology reviews and trials of red and near-infrared light and home devices. Sources were checked at the July 2026 update. Protocols differ, and results cannot automatically be transferred to every device.
- Mineroff J. et al. Photobiomodulation CME part II: Clinical applications in dermatology, 2024.
- Couturaud V. et al. Reverse skin aging signs by red light photobiomodulation, 2023.
- Park S.H. et al. Clinical study of home-use LED and infrared phototherapy for skin rejuvenation, 2025.
- Guo Z. et al. The Application of Light Emitting Diode in Cosmetic Dermatology, 2025.
- Glass G.E. The Clinical Applications of Low-Level Light Therapy, 2021.
Author: Eclipse editorial team. Last updated: July 2026. Eclipse does not claim individual medical review of this article. It does not replace advice from a dermatologist or another professional familiar with your skin, medicines and history.
