Near Infrared Sauna Safety Concerns: What You Need to Know

In recent years, “Full Spectrum” and “Near Infrared” (NIR) saunas have become a popular topic in the wellness industry. If you’re shopping for an infrared sauna, you’ve probably encountered these terms and wondered which type is actually best for your health.

At High Tech Health, we’ve been building infrared saunas for over 28 years, and we are frequently asked why we haven’t embraced full spectrum technology yet. It’s a fair question.

Our product development is strictly guided by peer-reviewed science. While we are open to offering Near Infrared options in the future for those who specifically request it, we currently focus exclusively on Far Infrared (FIR) saunas.

We believe our customers deserve access to the same research we use to make our product decisions. Rather than simply stating our position, we want to share the actual studies and biological mechanisms so you can evaluate the evidence yourself and make the choice that’s right for you. This article is our attempt to answer the questions we receive transparently and thoroughly.

What’s the Difference Between Near, Mid, and Far Infrared Saunas?

Infrared is light from the sun that we experience as heat. Infrared energy accounts for about 38.9% of the sun’s energy reaching the ground at sea level (Kochevar et al., 1999). Infrared light spans wavelengths from 760 nm to 1mm, separated into three bands—each used differently in infrared sauna technology:

Near Infrared (NIR): (780nm – 1400nm) Shortest wavelength; penetrates the skin differently than Far Infrared. Used in some full spectrum infrared saunas.

Mid Infrared (MIR): (1400nm – 3000nm) Middle wavelength; also included in full spectrum models.

Far Infrared (FIR): (3000nm – 1mm) The wavelength most associated with the deep, detoxifying sweat of traditional infrared sauna therapy. This is what we use at High Tech Health.

About half of IR-A energy that hits the body is absorbed in the dermis (Schroeder et al., 2006).

Is Near Infrared Safe in a Sauna? What the Research Says

While Near Infrared is used successfully in specific medical therapies (often using lasers or LEDs for targeted, focal treatment on small areas), its application in a general infrared sauna setting is different.

We have chosen to wait on integrating NIR as a standard feature because current research suggests that unregulated or prolonged exposure to Near Infrared requires caution. To be clear: we’re not suggesting that NIR is inherently dangerous or that companies offering full spectrum infrared saunas are doing something wrong. Different manufacturers weigh the available evidence differently, and that’s a legitimate part of how any industry evolves. Our goal here is simply to explain why we’ve made a different choice—for now—and to share the research that informs our thinking.

The following sections outline the biological mechanisms that give us pause.

Animal studies have since confirmed that near infrared promotes cataract formation, and have uncovered some of the mechanisms. Crystallin is a soluble lens structural protein that maintains the transparency of the lens. Crystallin degradation and decreased production cause a clouding of the lens, and are associated with cataract formation.

A study in 2011 found that near infrared exposure decreases crystallin levels, and changes its structure to a less soluble form (Aly, 2011).

A study in 2013 showed an increase in matrix metalloproteinases in the cornea and the lens after exposure to near infrared, an enzyme that degrades structural proteins. This parallels one mechanism by which near infrared causes skin damage (Dadoukis, 2013). Scientists have found only wavelengths under 3000nm (near and mid infrared) to cause this damage to the eye. Shorter wavelengths, 780um to 1400nm (near infrared), are the most damaging. Wavelengths over 3000nm (far infrared) have never been shown to damage the eye.

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) sets occupational limits on near infrared exposure. While animal studies have been able to determine thresholds for acute exposure causing immediate cataract formation, there is little data on safe levels of long-term exposure, and thresholds have not been established. The ICNIRP acknowledges that “cataract has been epidemiologically associated with chronic intermittent exposure at low irradiance”, as in a near infrared sauna or a full spectrum sauna.

Infrared Sauna Skin Benefits: Rejuvenation or Photoaging?

The goal of many infrared sauna users is skin rejuvenation. However, a growing body of dermatological research indicates that Near Infrared (specifically IR-A) may have the opposite effect (similar to the effect of exposure to ultraviolet light) if the intensity and duration are not carefully controlled. Photoaging is the formation of coarse wrinkles, uneven skin pigmentation, loss of skin elasticity, and a disturbance of skin barrier functions (Yaar, 2006).

Reactive Oxygen Species (ROS) and Oxidative Stress:

Studies have shown that NIR energy is absorbed by the mitochondria in skin cells, leading to the production of Reactive Oxygen Species (ROS), also known as free radicals. While ROS are natural in small amounts, an excess creates oxidative stress, consuming the body’s antioxidant resources (such as glutathione).

Accelerated Aging and MMP-1: The presence of excess ROS can trigger a specific biological chain reaction:

Enzyme Activation: ROS leads to the upregulation of an enzyme called Matrix Metalloproteinase-1 (MMP-1).

Collagen Breakdown: MMP-1 is responsible for degrading collagen (Type 1 and Type 3) and elastin fibers.

Visible Aging: This process, known as photoaging, is similar to the damage caused by UV light. It manifests as coarse wrinkles, loss of elasticity, and uneven pigmentation.

While some studies note benefits for wound healing, these often rely on specific, short-term dosing. In an infrared sauna, where exposure is habitual, the risk of “overdosing” the skin—potentially accelerating aging rather than reversing it is a concern we take seriously.

Cellular Health: DNA Repair, Apoptosis, and Cancer Risk

Perhaps the most complex area of research involves how Near Infrared interacts with cells that have existing damage (for example, from sun exposure). This is an important consideration for anyone using an infrared sauna regularly.

Interference with Natural Cell Death (Apoptosis): Normally, when a skin cell suffers genetic damage (like from UV rays), it undergoes apoptosis—a programmed cell death to prevent the damaged cell from becoming malignant.

The Concern: Some studies suggest that Near Infrared exposure may suppress this natural safety mechanism.

The Implication: Research has observed that NIR can alter the expression of genes related to apoptosis and DNA repair. By potentially allowing damaged cells to survive rather than being eliminated, there is a theoretical risk that NIR could contribute to the accumulation of mutations.

The Research:

Calles 2010 found that near infrared exposure affects the expression of 599 genes. 11 of those genes relate to apoptosis. Costa 2015 confirmed that reduced apoptosis is dangerous, especially because they also showed decreased repair of DNA. This is due to a reduction of GADD45a protein (specifically 57.2% decrease at 48 hours, and 34.6% decrease at 72 hours).

Kimeswenger 2016 specifically looked at near infrared effect on human melanocytes. Melanocytes are cells that produce melanin, which absorbs ultraviolet light to protect the skin. The worst form of skin cancer is melanoma and it forms in melanocytes. In this study, at 24 hours, by itself near infrared did not affect apoptosis, but in combination with UVB it significantly reduced apoptosis. They then looked at what effect near infrared was having on DNA repair (since DNA damage is the major trigger for ultraviolet radiation-induced apoptosis), and found that at 6h, 24h and 48h there was no effect from near infrared on DNA repair. They showed that near infrared was altering the expression of several apoptosis-related proteins. The conclusion was “Since IRA (near infrared) does not affect the repair of DNA-damaged melanocytes, the enhanced survival of severely DNA-damaged melanocytes might support the accumulation of UVB-induced mutations, malignant transformation, and ultimately melanomagenesis.” This means that evidence shows the possibility that near infrared is what makes UVB cause melanoma. This is a significant finding that warrants attention in the context of whole-body infrared sauna exposure.

Why “Positive” Near Infrared Studies Don’t Apply to Infrared Saunas

We are often sent studies by customers that appear to show benefits from Near Infrared exposure. We welcome these conversations—it’s one of the ways we stay current with the literature, and we genuinely appreciate customers who dig into the research.

We are familiar with these papers. We have analyzed them. And we’ve found that when you look closely at the methodology, many of these benefits are either time-dependent (disappearing or reversing over time) or device-dependent (using lasers, not infrared sauna heaters). Here is why that distinction matters.

Short-Term Benefits vs. Long-Term Infrared Sauna Use

One of the biggest issues with Near Infrared research is that some experiments simply didn’t wait long enough to see the fallout. The biological damage from NIR is often delayed.

The 72-Hour Delay (Costa et al., 2015): In this study, researchers noted a reduction in antioxidant enzymes after 24 and 48 hours. However, the spike in MMP-1 (the enzyme that destroys collagen) didn’t appear until 72 hours after exposure. If the study had stopped at two days, it might have looked safe. It wasn’t.

The Reversal Effect (Kim et al., 2006): This paper is particularly relevant for habitual infrared sauna users. The researchers measured the effects of a single dose of Near Infrared and saw positive results: MMP-1 went down, and procollagen (a marker of new skin growth) went up.

However: They then repeated the experiment to simulate regular use—three exposures per week for four weeks. The results reversed. MMP-1 levels shot up, and procollagen production decreased.

The Takeaway: A single exposure might look beneficial in a lab, but the cumulative, habitual exposure of a daily infrared sauna routine turns that benefit into accelerated aging.

The Myth of the “Sweet Spot” (Hormesis)

In 2016, researcher Barolet speculated that there might be a “hormetic zone” for Near Infrared. Hormesis is a biological phenomenon where a substance that is toxic at high doses might be beneficial at very low doses (like exercise, which is stress that makes you stronger).

While this is a valid scientific theory, it is currently difficult to apply reliably in an infrared sauna setting.

Unknown Thresholds: We do not know where this “safe zone” begins or ends for the human body.

Uncontrollable Variables: Even if a “safe zone” exists, an infrared sauna is a 3D space. As you lean forward, lean back, or move closer to a heater, your dosage changes instantly. It is difficult to design an infrared sauna heater that keeps you in a theoretical safety zone while you are moving around the cabin.

If future research establishes clear, replicable dosing guidelines for whole-body NIR exposure, we would be eager to revisit this.

Laser Therapy vs. Infrared Sauna Heaters: A Critical Distinction

Much of the positive research on Near Infrared (including the Barolet paper) focuses on Low Level Laser Therapy (LLLT) or Photobiomodulation (PBM).

These are fundamentally different applications:

LLLT/PBM: Uses cold lasers or LEDs applied directly to the surface of the skin. The power is low, controlled, and targeted.

Infrared Sauna Heaters: These are high-power devices designed to heat a room. They emit a wide, uncontrolled spectrum and must be placed at a distance.

There is currently no evidence that the results achieved by a precision medical laser applied to a specific lesion apply to a high-output infrared sauna heater exposing the entire body.

A Note on Wound Healing Claims

Finally, some companies market near Infrared saunas for “wound healing.”

First, from a legal and safety standpoint: If you have an open wound, please seek medical attention, not an infrared sauna. Any company suggesting their sauna is a medical device for wound healing needs to be very careful about violating FDA regulations.

Second, the science suggests this is counter-productive for long-term health. As concluded in the Darvin 2010 paper, while NIR might have a use for treating infrequent lesions, it should be avoided for habitual use due to the production of free radicals.

In other words: Targeted medical application of Near Infrared may be a useful medical tool for specific, infrequent problems—that doesn’t necessarily mean it belongs in a wellness tool like an infrared sauna designed for daily, lifelong use.

Full Spectrum Infrared Sauna: Is It Worth It?

Many companies offer full spectrum infrared saunas that combine Near, Mid, and Far infrared heaters. Some of these companies, recognizing the research cited above, advise users to simply turn off the Near/Mid heaters if they are concerned.

This is a reasonable accommodation, but it does present a practical consideration for the consumer:

Reduced Efficacy: If you turn off the Near/Mid heaters in a full spectrum infrared sauna, you are often left with only a fraction of the heaters working. This reduces the total heat output and may compromise the effectiveness of the session.

Value Consideration: You may be paying a premium for technology that you might choose not to use.

We’re not suggesting this makes full spectrum infrared saunas a bad choice for everyone—just that it’s worth understanding how these systems work before making a purchase decision.

Do Infrared Sauna “Programs” and “Recipes” Actually Work?

You may also see companies marketing specific “programs” or “recipes”—presets on a digital tablet that claim to mix specific levels of Near, Mid, and Far infrared to achieve distinct outcomes like “Weight Loss,” “Cardio,” or “Detoxification.”

While this concept appeals to our desire for high-tech optimization, it is important to recognize that these claims have no basis in peer-reviewed science.

No Physiological “Code”: There is currently no medical literature suggesting that the human body requires a specific “recipe” of 20% Near Infrared and 80% Far Infrared to induce weight loss, versus a different ratio for pain relief.

Marketing vs. Biology: The benefits of infrared sauna therapy—cardiovascular conditioning, detoxification, and metabolic increase—are primarily driven by systemic core body heating. By modulating or dimming heaters to create a specific “recipe,” these programs often reduce the total infrared energy reaching your body, potentially lowering the infrared sauna’s overall efficacy.

At High Tech Health, we focus on delivering a consistent, maximal output of the safest and most effective wavelength: Far Infrared.

How to Choose the Best Infrared Sauna for Your Health

At High Tech Health, we build infrared saunas designed for daily, lifelong use. Currently, Far Infrared is the only band with a decades-long track record of safety and efficacy for whole-body hyperthermic therapy. It provides the deep, detoxifying sweat our customers seek without the concerns about eye health or photoaging associated with NIR.

We want to be clear about our position: we’re not opposed to Near Infrared technology. We’re not claiming that companies who offer it are being irresponsible. The wellness industry is full of good-faith disagreements about how to weigh emerging research, and reasonable people can look at the same studies and reach different conclusions.

That said, we do think it’s worth being a discerning consumer. In any industry, “more features” can become a selling point in itself—and “Full Spectrum” certainly sounds more comprehensive than “Far Infrared only.” It’s natural to assume that three wavelengths must be better than one. But as we’ve tried to show in this article, the science doesn’t support that assumption. Sometimes, more isn’t better—it’s just more. We’d encourage anyone shopping for an infrared sauna to look past the feature list and ask what the research actually says about each technology for the specific use case of daily, whole-body exposure.

What we’ve tried to do here is explain our reasoning—openly and with citations—so that you can make your own informed decision. We believe that’s more useful than marketing claims in either direction.

We are constantly monitoring the research. Should a safe, standardized protocol for whole-body Near Infrared become available—or for customers who understand the research and specifically desire NIR—we may offer it as a specialized add-on in the future.

Until then, we stick to what is proven: High-quality, far Infrared sauna technology that supports your health without compromise.

References

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