Does Infrared Light Therapy Actually Work?

Near-infrared wavelengths (roughly 700–1000 nm) penetrate a few millimetres into tissue and get absorbed by an enzyme inside the mitochondria called cytochrome c oxidase — the last link in the chain that makes cellular energy (ATP). Under stress or inflammation, nitric oxide builds up and jams this enzyme; the absorbed photons knock the nitric oxide loose, letting oxygen bind again so energy production can pick back up.¹

That single event cascades outward: the freed nitric oxide dilates nearby blood vessels and improves local circulation, a brief burst of reactive oxygen species switches on repair genes, and inflammatory signalling (TNF-α, IL-6) gets turned down while anti-inflammatory signalling goes up. This family of effects has a name — photobiomodulation, sometimes still called low-level laser therapy from its early days using lasers rather than LED panels.¹ It is a real, mechanistically plausible pathway and not a new idea; it has simply moved from physiotherapy clinics into living rooms.

Pain is where the evidence is strongest. A Lancet meta-analysis pooling 16 randomized trials in over 1,200 patients found low-level light therapy meaningfully reduced acute and chronic neck pain, with the effect still measurable up to 22 weeks later.² A separate review of trials in knee osteoarthritis reported consistent improvements in pain and function, though study quality and dosing varied enough that the authors call it moderate rather than high-grade evidence.³

Skin shows a real, modest effect. In a randomized controlled trial, 30 sessions of combined red and near-infrared light over several weeks significantly increased measured collagen density and improved wrinkles and skin roughness compared with untreated skin.⁴ It is not a replacement for retinoids or sunscreen, but the underlying biology — more fibroblast activity, more collagen — checks out in a controlled trial, not just a before-and-after photo on a product page.

These get sold under the same word, but they are not really the same intervention. A light panel or LED mask delivers a narrow band of red/near-infrared wavelengths to a specific area without much heating — the mitochondrial mechanism above is the whole story. An infrared sauna heats your whole body using infrared heating elements instead of hot air; most of what happens there is simply the physiology of passive heat exposure — broadly the same cardiovascular adaptations you would get from a traditional Finnish sauna.⁵

A systematic review and meta-analysis across both infrared and traditional sauna bathing found consistent improvements in exercise capacity and quality-of-life measures in people with heart failure, alongside good short-term tolerability.⁵ That is a genuinely encouraging result for a passive, low-effort habit — but it is a heat-and-circulation effect, not evidence that extra infrared wavelengths beat a regular sauna for your heart. If cardiovascular benefit is the goal, how often you sauna probably matters more than whether the heat comes from electric coils or infrared panels.

Photobiomodulation follows a dose-response curve that bends the wrong way at high doses — more is not better, and overdosing a panel session can blunt rather than boost the effect. Manufacturer session times (typically 10–20 minutes) are built around this, so there is little upside to running a panel longer than instructed.

Infrared saunas carry the same precautions as any sauna: stay hydrated, skip it if you have uncontrolled low blood pressure or a heart condition without medical clearance, and avoid it in pregnancy unless your doctor has specifically cleared it — core body temperature matters more there than which heat source raised it.