Photobiomodulation Explained

The key points

• Light can interact with cellular photoacceptors and signalling pathways.
• A plausible mechanism does not prove a clinical benefit.
• More power, more wavelengths or longer sessions are not automatically better.
• Skin, local muscle treatments and full-body beds have different research evidence.

Already looking for an appointment? Explore full-body Red Light Therapy sessions or Red Light Therapy for Skin.

What is photobiomodulation?

PBM applies light to influence biological processes through non-ablative exposure. It is also encountered in research under terms such as low-level light therapy and low-level laser therapy.

Red and near-infrared wavelengths, often within roughly 600–1000 nm, feature in much of the literature. That is a common research range, not a complete definition of every PBM protocol.

A session’s duration is set by the device and intended protocol. My BioHealth’s full-body session is 20 minutes; that does not mean all PBM treatments use the same exposure time.

Why one mechanism is studied across different applications

Cellular signalling is relevant to skin, muscle and tissue-repair research, which helps explain the breadth of PBM studies. Each application still needs its own evidence.

A study in one tissue, using a particular device or clinical protocol, cannot establish a benefit in another area. A wellness bed, a targeted physiotherapy device and an experimental laboratory preparation answer different research questions.

How light interacts with cells

Photoacceptors are molecules that absorb light and can participate in a biological response. One leading proposed pathway involves cytochrome c oxidase, an enzyme in the mitochondrial electron transport chain.

Mitochondria help cells produce ATP, the molecule used to transfer energy for normal activity. Research examines how light absorption interacts with electron transport, nitric oxide and downstream signalling.

Cytochrome c oxidase is a candidate photoacceptor, not a complete explanation of every PBM effect. Other processes and photoacceptors are investigated, with responses affected by the tissue and its condition.

Some experimental work explores different responses in stressed or damaged tissue. That does not establish a stronger clinical benefit for everyone with fatigue, pain or injury.

Read Mitochondria and Cellular Energy and the mechanism review for more detail.

Why dose matters

PBM research describes a biphasic dose response: too little exposure may provide insufficient stimulus, while increasing exposure beyond a useful range can reduce the response or become inhibitory.

This helps explain why sessions are planned rather than simply made longer or stronger. A useful dose depends on the intended target and protocol; there is no single threshold that applies to every tissue or device.

Wavelength, irradiance, energy dose, exposure time, frequency, positioning and the area treated all matter. A device specification alone cannot tell you what dose reaches the intended tissue.

Wavelength and tissue penetration

Different wavelengths are absorbed and scattered differently. Visible red generally acts more superficially than near-infrared, but light does not stop at one fixed depth.

Melanin, haemoglobin, water, tissue thickness and device positioning influence delivery. Near-infrared wavelengths do not guarantee that a particular muscle or joint receives a clinically effective dose.

A direct human-skin study found substantial attenuation of 850 nm light within the first millimetre. This illustrates why fixed claims such as “penetrates exactly 5 cm” are too simplistic; it does not mean all light disappears at that point.

Multiple wavelengths can provide different exposure characteristics. Wavelength count alone does not establish broader clinical benefit or make a device superior.

My BioHealth’s full-body bed uses 589 nm amber, 630 and 660 nm red, and 850 nm near-infrared. View the service pages for the specific session and wavelength illustrations.

LED and laser delivery

Lasers commonly deliver a focused beam at a selected wavelength. LEDs commonly expose a wider area, with arrays able to combine wavelengths. Both are used in PBM research.

Laser coherence means light waves have a defined relationship. It is not generally treated as a necessary condition for all PBM effects, but delivery characteristics still matter.

Evidence from one device cannot simply be transferred to another because both emit red light. Dose, coverage, treatment target and protocol need to be considered together.

What happens after exposure?

Research investigates changes in cellular energy processes, gene expression and signalling following light exposure. The timing and duration of those changes depend on the experimental conditions.

Many studies use repeated sessions. This does not mean every effect is cumulative, every person needs the same course, or every session produces a noticeable change. Mechanism research cannot set an individual treatment schedule.

What the clinical evidence shows

Muscle strength and recovery: a retained trial

The randomised, double-blinded, sham-controlled crossover study cited in the existing article tested muscle strength and recovery after exercise. It reported no benefit for the measured muscle outcomes under its protocol.

This is an important part of the evidence, rather than a reason to remove the reference. A controlled design can produce a negative result.

Full-body and local PBM

A 2025 systematic review of whole-body PBM included five eligible studies and found no evidence of benefit for exercise recovery or performance biomarkers, with a possible sleep-quality signal. Its findings should not be replaced by results from smaller targeted devices.

Skin: red and amber comparison

The retained 2023 periocular study compared 660 nm red and 590 nm amber light on opposite sides of the face at the same dose. It reported wrinkle-volume reductions of 31.6% and 29.9%, respectively, without improvement in hydration or viscoelasticity.

These are findings from that specific split-face protocol. Both sides received light; this was not a comparison against an untreated face. The study does not predict a 30% change from My BioHealth’s full-body bed.

Safety research

A 2023 systematic review examined oncologic safety in aesthetic skin rejuvenation. Across seven clinical PBM trials, four patients had mild temporary redness, with no other adverse events reported in those trials.

The review’s scope does not establish safety for every device, setting, health condition or cancer history. Screening remains relevant.

Mechanism and outcome are different evidence

A laboratory pathway can explain a plausible biological response. Clinical studies measure outcomes in people. Neither should be presented as interchangeable proof, and a manufacturer’s preparation or device capability is a different form of evidence again.

How to interpret a PBM claim

Ask what was studied, with which device, wavelength and dose, in which population, and against what comparison. Look at the outcome measured, follow-up period and limitations.

Skin appearance, muscle performance, pain and return-to-play are different outcomes. Improvement in one does not prove improvement in the others.

Suitability and practical considerations

PBM is often described as low risk, but suitability depends on the device, protocol and person. Disclose medicines that increase light sensitivity, relevant eye conditions, skin cancer or undiagnosed lesions, pregnancy and other health concerns before booking.

Follow the specific service’s screening and eyewear instructions. Persistent or unexplained symptoms need appropriate assessment. Wellness exposure is not equivalent to treatment prescribed for a diagnosed condition.

People commonly explore PBM for skin appearance, recovery routines and general wellbeing. These interests are reasons to seek information, not a diagnosis or guarantee of benefit.

Common questions

Is the evidence the same for skin and muscle recovery?

No. Some proposed mechanisms overlap, but the devices, protocols and clinical outcomes differ. Each application needs its own relevant evidence.

How does this connect to HBOT?

HBOT changes oxygen availability while oxygen is breathed under increased pressure. PBM uses light to interact with biological signalling. Some clients explore both in a recovery routine; My BioHealth does not claim a proven synergistic benefit.

Is more powerful light always better?

No. Dose and target matter, and excessive exposure can reduce a response. Power alone is not a quality or outcome measure.

Do more wavelengths guarantee better coverage or results?

No. Wavelengths influence light delivery, but the dose reaching tissue and clinical relevance depend on the complete device and protocol.

Explore My BioHealth sessions

My BioHealth offers private 20-minute full-body Red Light Therapy sessions in Campbellfield, Melbourne, using amber, red and near-infrared light.

View Full-Body Red Light Therapy Sessions · Explore Red Light Therapy for Skin

For related reading, explore Mitochondria and Cellular Energy, Understanding Hyperbaric Oxygen Therapy or the Evidence Hub.

References

• Mechanisms and applications of the anti-inflammatory effects of photobiomodulation — retained mechanism review.
• Does Photobiomodulation Therapy Enhance Maximal Muscle Strength and Muscle Recovery? — retained trial, including negative findings.
• Photobiomodulation Reduces Periocular Wrinkle Volume by 30%: A Randomized Controlled Trial — retained red-versus-amber protocol.
• Oncologic safety systematic review for aesthetic skin rejuvenation — retained safety reference.
• Whole-body PBM systematic review, 2025 — additional full-body context.
• Depth of penetration of 850 nm light in human skin — additional penetration context.

General information, not individual medical advice. Ask your healthcare professional about suitability for your circumstances.