If you want genuine red light therapy in a sauna, the spec to demand is a published wavelength pair and an irradiance figure — something like 660 nm red plus 850 nm near-infrared at a stated mW/cm2. Almost no sauna listing publishes both, which is the single most useful fact on this page. Most cabins advertising "red light" are offering chromotherapy: coloured LED mood lighting at an intensity nowhere near therapeutic. That is not a scandal — it is pleasant, and it is cheap — but it is not the thing the term describes, and you should not pay a therapy premium for it.
Informational only, not medical advice. Red and near-infrared light therapy is an active research area with genuinely mixed evidence, and nothing here is a treatment claim. We do not run a lab and we do not test irradiance. If you are considering light therapy for a medical condition, that is a conversation with a clinician. Our
sauna safety guide covers who should be cautious about heat exposure generally.
The three things sold as "red light" in a sauna
1. Chromotherapy. A low-power RGB LED strip or spotlight that can be set to red, blue, green and so on. It is in a large share of infrared cabins, it is usually described as "chromotherapy" or "colour therapy" in the specifications and as "red light" in the marketing, and it produces a coloured glow rather than a therapeutic dose. No wavelength and no irradiance figure will be published, because there is nothing flattering to publish. Enjoy it as lighting — our sauna lighting guide covers that side — but do not count it as therapy.
2. A real red / near-infrared LED panel. Purpose-built photobiomodulation hardware: banks of LEDs at specific wavelengths, usually around 660 nm (visible deep red) and 850 nm (near-infrared, invisible), with a published irradiance at a stated distance. This is what the term means in the research literature. In the home-sauna market it appears either as a standalone panel you hang or stand in front of, or as an integrated option on a handful of units.
3. Near-infrared heat from a full-spectrum heater. Full-spectrum infrared cabins add near- and mid-infrared emitters to the far-infrared panels that do the heating. Near-infrared overlaps the wavelength region red-light devices use, which is why full-spectrum cabins get marketed with skin and recovery language. The distinction that matters: these emitters are built to deliver heat across a broad band, not to deliver a controlled dose at a specific wavelength. It is a real difference from far-infrared-only, and it is not the same thing as a 660/850 panel. Our full spectrum vs far infrared page is the detail, and infrared sauna vs red light therapy compares the two categories head on.
How to read a listing in ninety seconds
| What the listing says | What it almost certainly is | What to ask for |
|---|
| "Chromotherapy lighting" or "7 colour LED" | Mood lighting | Nothing — price it as lighting |
| "Red light therapy" with no numbers | Usually chromotherapy, occasionally a weak panel | Wavelength in nm and irradiance in mW/cm2 |
| "660 nm + 850 nm" with an irradiance figure | A real red/NIR panel | Distance the irradiance is measured at, and coverage area |
| "Full spectrum" / "near infrared heaters" | A broad-band heater, not a dosed panel | Which bands, and the electrical requirement |
The three units below are the ones in our registry that sit in different boxes on that table, and we have placed them deliberately: one has built-in red-light LEDs alongside its far-infrared heating, one publishes an actual wavelength pair and irradiance figure, and one is a full-spectrum cabin whose near-infrared is heat rather than a dose. None of them is a medical device, and we make no treatment claim for any of them.
What a published figure actually tells you
The SAUNABOX red-light tent is worth a paragraph purely as an example of disclosure. The brand publishes 660 nm and 850 nm as its wavelengths and 80.43 mW/cm2 at the panel surface as its irradiance, and rates the panel IP65 for humidity. You can argue with any of those numbers, but you can argue with them — which is more than you can do with "red light therapy included".
Two caveats to read alongside any irradiance figure. First, "at the surface" is the most flattering place to measure; irradiance falls off with distance, so a number at the panel face tells you little about what reaches you sitting back from it. Ask at what distance. Second, coverage matters as much as intensity: a panel aimed at a seated torso in a 35-inch-square tent is a partial-body exposure, not a full-body one.
On the heat side, the IP65 rating is the genuinely important spec for a humid environment. An unrated LED array inside a steam tent or a sauna is a failure waiting to happen, and it is the reason most reputable sauna makers keep real light panels out of the hot, wet zone entirely.
The cheaper and usually better approach
If red light matters to you and the sauna matters to you, consider buying them separately. A standalone panel gives you a larger emitting area, a published irradiance, a usable distance, and the ability to use it on days you do not feel like a sauna — and the sauna you buy can then be chosen on heat, wood and electrics rather than on a lighting option. An integrated unit is tidier and costs less than two devices, but you are accepting whatever panel the sauna maker chose, permanently, inside a hot wet box.
That said, there is an honest case for integration: the habit. A panel in a cupboard gets used for three weeks. A panel in the sauna you already sit in four times a week gets used four times a week. If that is the difference for you, it is a legitimate reason to pay the premium — and the Dynamic Andora is the example of an infrared cabin that bundles red-light LEDs in at a mainstream price rather than as a luxury add-on.
What we would not do is pay a large premium for "full spectrum" purely to get near-infrared as a light therapy. Full-spectrum cabins are worth their money for the heat quality — and they typically need a 240V circuit for it, which is a real cost, so read do infrared saunas need special wiring before you commit. The light-therapy framing is marketing laid over a heater.
And a word on EMF, since it always comes up
Cabins that advertise light therapy tend to also advertise low EMF, and the two claims get tangled together. EMF in this category refers to the magnetic fields near heating elements, which is a separate question from light wavelengths entirely. The NIEHS summary of the research is the sober starting point, and our EMF explained page covers what the ratings on these listings do and do not mean. A cabin with a published low-EMF rating and chromotherapy lighting is still a cabin with chromotherapy lighting.
For the broader health evidence on heat exposure itself — which is far better established than the light claims — the Mayo Clinic Proceedings review and the Finnish cohort work are the two documents worth reading, and our sauna benefits page summarises them.
