What is red light therapy?

Red light therapy — also called photobiomodulation (PBM) or low-level light therapy (LLLT) — uses specific wavelengths of red and near-infrared light to produce biological effects in the body at a cellular level.

Unlike ultraviolet light, which damages tissue, or heat-based treatments, which work through thermal effects, red and near-infrared light works through photochemistry. The light is absorbed by specific molecules inside your cells and triggers a cascade of natural repair, regeneration and anti-inflammatory processes. Nothing is added to the body. Nothing is damaged. The light activates biological processes that the body already knows how to run — it simply gives those processes more of what they need to work effectively.

Red light therapy is not a single device or product. It encompasses a spectrum of clinical applications — from whole body systems that treat every cell simultaneously in a single session, to laser probes that deliver concentrated light to a precise tissue or injury site. At Aim Health in Hoylake, we offer both: the MitoGen medical-grade whole body PBM system, and THOR laser therapy for targeted treatment of specific conditions.

How red light therapy works — the science

The mechanism of red light therapy begins inside the mitochondria — the energy-producing structures present in almost every cell in the body.

The mitochondrial mechanism

Mitochondria produce ATP — adenosine triphosphate — the molecule that powers every cellular process, from muscle contraction to immune function to tissue repair. The key target for red and near-infrared light is an enzyme called cytochrome c oxidase — complex IV of the electron transport chain. When exposed to specific wavelengths of light in the red (620–700nm) and near-infrared (700–1100nm) range, cytochrome c oxidase absorbs the light energy and uses it to increase ATP production, release nitric oxide, and generate signalling molecules that trigger a cascade of downstream repair and regeneration effects.

The result is a cell that has more energy, better circulation, reduced inflammation, and an enhanced capacity to repair and regenerate — all triggered by the light, all produced by the cell’s own biological machinery.

What happens during a session

The wavelengths that matter

Red wavelengths (620–700nm) penetrate to a depth of several millimetres and are most effective for skin, superficial tissue and wound healing. Near-infrared wavelengths (700–1100nm) penetrate significantly deeper — several centimetres into muscle, bone and even brain tissue — and are the primary driver of the systemic and neurological effects of PBM. Effective clinical systems use both ranges simultaneously.

Whole body PBM vs THOR laser — what is the difference?

At Aim Health we offer two distinct red light modalities. Understanding the difference helps clarify which is most appropriate for different goals and conditions.

Whole body photobiomodulation — the MitoGen system

Whole body PBM treats the entire body simultaneously in a single session. The MitoGen system delivers red and near-infrared light across every part of the body in a 20-minute session — stimulating mitochondrial function systemically, reducing whole-body inflammation, and supporting the full range of cellular repair processes across all tissue types at once.

Whole body PBM is most appropriate for conditions that are systemic in nature — chronic fatigue and long COVID, inflammatory skin conditions, sleep and nervous system dysregulation, and general recovery, health optimisation and healthy ageing. The coverage is the defining advantage.

THOR laser therapy — precise targeted treatment

THOR laser therapy uses both laser and LED probes to deliver concentrated red and near-infrared light to a specific tissue, joint, nerve or injury site. The light is applied directly to the target area, achieving a higher local irradiance than whole body systems can deliver to any specific point, and allowing precise targeting of deep structures including tendons, joints, spinal tissue, nerve pathways and specific wound sites.

THOR laser is most appropriate for localised conditions — a specific joint, injury or pain site. Tendon injuries, nerve pain, joint conditions, wound healing at a particular site, post-surgical recovery at a specific location, and localised nerve conditions all respond particularly well to the targeted delivery that THOR laser provides.

What conditions does red light therapy help?

Chronic fatigue and long COVID

Mitochondrial dysfunction is increasingly recognised as a central mechanism in chronic fatigue and long COVID. Red light therapy works directly at this level — restoring ATP production, reducing systemic inflammation, supporting sleep architecture, and providing transcranial near-infrared stimulation that reaches cortical brain tissue. Read our dedicated article: Red Light Therapy for Chronic Fatigue and Long COVID.

Skin conditions — eczema, psoriasis, rosacea

Inflammatory skin conditions are driven by immune dysregulation and cellular dysfunction deep in the tissue. Red and near-infrared light reduces the inflammatory signals that drive flare-ups, supports skin barrier function, stimulates collagen production, and improves circulation in skin tissue. Whole body delivery treats every affected area simultaneously. Read our dedicated article: Red Light Therapy for Eczema, Psoriasis and Rosacea.

Surgery recovery and wound healing

Red light therapy supports all three phases of wound healing — reducing inflammatory burden in the first days, stimulating fibroblasts and collagen synthesis in the proliferative phase, and improving scar quality in the remodelling phase. Studies show collagen production increases of 138–211% with regular therapy. Read our dedicated article: Red Light Therapy for Surgery Recovery and Wound Healing.

Pain — joint, muscle, nerve and chronic pain

THOR laser therapy has a particularly strong evidence base for pain relief, including musculoskeletal pain, neuropathic pain, joint conditions, tendinopathies and post-operative pain. Read our dedicated article: THOR Laser Therapy — How Light Accelerates Healing.

Sports recovery and performance

Red light therapy reduces delayed onset muscle soreness (DOMS), accelerates recovery from training, supports tissue repair after injury, and improves mitochondrial efficiency in muscle tissue. Studies show meaningful improvements in strength, endurance and recovery rates with regular pre and post-exercise sessions.

Healthy ageing and collagen

Red light therapy has one of the strongest evidence bases of any non-invasive approach to skin ageing — with documented collagen increases of 138–211% and measurable improvements in skin texture, tone and elasticity. Beyond the skin, the mitochondrial stimulation, anti-inflammatory effects and circadian rhythm support of regular PBM have broad implications for healthy ageing at a cellular level.

Sleep and nervous system

Regular red light therapy improves sleep quality through multiple mechanisms — direct stimulation of circadian clock cells, reduction of systemic inflammation that disrupts sleep architecture, and nervous system calming effects. Many clients report sleep improvement as one of the earliest and most noticeable changes from a course of sessions.

Neurological health and brain fog

Near-infrared wavelengths above 800nm penetrate the skull and reach cortical brain tissue. Transcranial PBM has demonstrated improvements in cognitive function, neuroinflammatory markers, and neurological recovery across multiple conditions including traumatic brain injury, long COVID cognitive impairment, and age-related cognitive decline.

The MitoGen whole body system at Aim Health

At Aim Health in Hoylake, our whole body red light therapy sessions use the MitoGen medical-grade photobiomodulation system — one of the most advanced whole body PBM systems available in clinical use.

The MitoGen system delivers both red and near-infrared wavelengths across the full body surface simultaneously, treating every cell at every tissue depth in a single 20-minute session. The system is calibrated to deliver therapeutic irradiance — the light intensity at the tissue level that clinical research demonstrates is necessary to produce biological effects. This is a critical distinction from consumer home devices, which typically deliver a fraction of the irradiance of clinical systems and cannot achieve the systemic effects that medical-grade whole body delivery produces.

Sessions are conducted lying comfortably on the treatment bed. There is no heat, no discomfort and no sensation during a session. Most clients find sessions deeply relaxing — many fall asleep. There is no recovery time required.

THOR laser therapy at Aim Health

THOR Laser is one of the most widely used and extensively validated low-level laser therapy systems in clinical practice globally, used in hospitals, physiotherapy clinics and specialist pain centres across more than 70 countries. The THOR system uses both laser and LED probes to deliver precisely calibrated wavelengths to target tissues, with protocols developed and validated through decades of clinical research.

At Aim Health, THOR laser is used to treat a wide range of localised conditions — from specific joint and tendon injuries to post-surgical recovery at a defined site, nerve pain, wound healing, and conditions affecting specific musculoskeletal structures.

THOR laser sessions are 15 to 20 minutes depending on the condition and protocol. A clinician applies the probe or cluster head directly to the target area. There is no pain, heat or discomfort involved. There is no recovery time required.

What to expect at Aim Health, Hoylake

The evidence

Red light therapy has one of the most extensively documented evidence bases in non-invasive medicine — with over 6,000 peer-reviewed studies published on photobiomodulation across its applications.

A 2013 study in the Journal of Drugs in Dermatology found significant reductions in eczema severity after four weeks of red light treatment. A 2024 meta-analysis covering 18 randomised controlled trials and 670 skin wounds found significant wound-size reduction and pain relief with consistent PBM treatment. Studies across surgical recovery populations have demonstrated collagen production increases of 138–211%, alongside faster wound closure, reduced scarring and lower rates of wound complication.

For chronic fatigue and neurological applications, multiple controlled trials demonstrate significant reductions in fatigue with the mechanism — restored mitochondrial ATP production and reduced oxidative stress — well-established in laboratory and clinical settings.

For pain and musculoskeletal conditions, systematic reviews consistently show significant reductions in pain and inflammation with THOR and equivalent laser protocols across joint conditions, tendinopathies, neuropathic pain and post-operative pain.

The World Association for Laser Therapy (WALT) and the North American Association for Photobiomodulation Therapy (NAALT) have published clinical guidelines recognising low-level laser and photobiomodulation therapy as evidence-based interventions for a range of conditions.

Frequently asked questions

Further reading

References