Is Red Light Therapy Safe or dangerous? Taking one step back, one can realize that anything in the world that we interact with can be dangerous if used in the wrong way or by someone with an unusual health condition or sensitivity. For example, some people are allergic to water - which in their case, would make something as routine as taking a shower dangerous (Yes, incredibly, that's a real thing!).
In order to better understand how safe or dangerous something is, we have to look at the context, as well as the definitions of the terms being used around that topic.
The majority of research does indicate that for most people red light therapy is considered to be one of the safest types of treatment to support health and wellness.
So, is red light therapy safe? Let's dig into this often asked question and try to consider it from all angles while dispelling the myths.
Red light therapy is often misunderstood
Although Red Light Therapy (RLT) has been around for decades, it has only become popular with the general public in recent years. As often happens, the chatter around RLT has included some less-than-accurate speculation about its purported dangers.
Some of the opinions have been based on easily refuted mistakes. Some have been based on some very isolated cases. The goal of this article will be to examine different concerns about red light therapy as well and see if they have merit or whether they are based on a lack of understanding.
All Treatments have some contraindications
For starters, it is important to acknowledge that all wellness treatments will have some contraindications, meaning they might not be medically appropriate for everybody - regardless of how safe they are for most people. Red Light Therapy is no exception, although the list of contraindications is quite short.
The list does exist, and you can read about it here. However, this does not mean it is dangerous for the average person. That's why we emphasize the need to start out slowly, just like you would with any other treatment, and check with one’s doctor before starting to use any red light therapy device.
For the purposes of this discussion, the Red Light Therapy devices we are discussing are:
- Not intended to be in direct contact with the skin - although the dangers from devices designed for direct skin contact are also very limited
- Have a level of intensity below what has been determined to be the safe upper limit (which includes the vast majority of panels)
- Use LEDs and not lasers
- Emit wavelengths that are between 600 - 1000nm which includes both the visible red and almost invisible NIR wavelengths
Red Light Therapy devices do not burn people
The opinion stated by individuals who might be experts in healthcare—but not necessarily red light therapy experts—is that after 20 minutes, red light therapy devices will begin to cause burns or blisters.
This statement is heavily exaggerated. Red light therapy wavelengths which lie on the 600-700 nm and 800-1000 nm ranges of the light spectrum, are by nature non-heating.
In concentrations of well under 200 mw/cm2 (as measured by lab instrumentation and not hand held solar meters) red light will not cause blistering or burning if used for a reasonable amount of time, unless someone has rare skin sensitivity or health condition.
Red Light therapy's benefits do not come from thermal action, and therefore are obtained without needing to be concentrated enough to burn. Additionally, most red light therapy devices on the market today come with timers that turn off automatically after 20 - 30 minutes.
To put things into perspective; according to the National Fire Protection Association (NFPA), in the United States alone, heating pads and heating blankets tragically cause an average of 340 house fires, 1500 severe burns and 8 deaths every year.
Conversely, there are no recorded instances of death, fire or serious burns from the use of Red Light Therapy devices. Let’s unpack that even further.
An extremely safe track record
The thousands of studies done on red light therapy support its safety profile and notable lack of adverse events. For example, one such study conducted by a large group of doctors and scientists states that “LED-NIR light has been safely used since the late 1980s.” And from one other study: “for non-thermal photorejuvenation… LED light sources have been demonstrated to be safe and effective".
In all of its history, there are possibly two cases of burns reported with red light therapy devices using either low level lasers or LED’s.
One was in a study that was deliberately using very high intensity lights to find the upper levels of safety where one person developed a very small blister at 872 mn/cm2 for a 30 to 90 minute treatment. The other instance was with a specific higher powered device in which case the patient made a claim to the FDA but never followed through. The claim was never validated.
Depicting all red light therapy as devices that may potentially burn or damage skin if one goes a little beyond the recommended treatment time only serves to cause confusion. While everyone who tries this treatment should check with their doctor, the track record of red light therapy delivered by LEDs is one of proven and overwhelming safety.
While we do not advise going past the recommended treatment times, it is not because the extended time frame will cause any great harm or danger. Rather, it's because it will simply prevent the person from receiving an optimal dose. As a result the therapy may not work as well or it may not work at all.
The mild side effects that can happen from overuse are listed in this blog post: What Are the Side Effects of Red Light Therapy?.
And if you want to avoid the common mistakes of using RLT check out 10 Mistakes You Might Be Making Using Red Light Therapy At Home.
Let’s understand how the light is measured
Part of the problem when discussing Red light therapy is that there is a lot of confusion surrounding irradiance levels. Those are measurements that indicate how strong the light coming from the device actually is.
The challenge has been that instruments that accurately measure irradiance tend to be very expensive and may require advanced technical knowledge. A cheaper and more accessible alternative has been the handheld solar power meter which unfortunately tends to yield readings that are consistently higher than what the lab instruments report.
Due to these higher readings becoming the industry standard, it is difficult for brands to break away from this norm. As noted in our post Rouge vs the Competition: A Buyer's guide to choosing the best red light – Rouge Care, we are working towards using and encouraging better testing methods and more consistent reporting across our industry.
With this understanding, it is good to note that most panels are typically under 100 mw/cm2 as measured by lab instruments which is the standard used in most research papers.
Can you have too much of a good thing?
This brings us to the next question: how much power is needed to get the best red light therapy results? And at what point does a good thing become too much?
The present consensus is that anywhere between 10-50 mw/cm2 is a very good range for therapeutic benefits, where the higher irradiance will help with deeper tissue penetration of the NIR wavelengths and the lower irradiance is better for skin and surface benefits. Therefore, the 50-75 mw/cm2 that is reached by the top performing red light panels on the market is more than adequate to achieve optimal clinical results.
The conclusion from some in-depth studies is that there is a sweet spot somewhere in the middle of the strength ranges and will likely vary from one person to another.
From this research, you can conclude that you really do not need lights that are in the 200 mw/cm2 irradiance levels (as measured by lab instrumentation), as one could be approaching a level that should only be used under clinical supervision.
The upper limits of safety have been reported to be around 200 mw/cm2 (as tested by a lab instrument) at which level even LEDs can begin to burn tissue. The highest irradiances reported on the commonly available panels, is about 85mw/cm2.
As long as the red light therapy products we are discussing fall within these ranges—as most clearly do—the safety profile remains positive for users. Products that can truly burn people are just not commonly available on the open market.
Some people mistake lasers for LEDs
Many people, including regulatory agencies, use the terms laser and LEDs interchangeably, which can cause confusion as they are, fundamentally, very different things
What are lasers? From NASA’s own educational website “a laser is an unusual light source. Lasers produce a very narrow beam of light. This type of light is useful for lots of technologies and instruments…Lasers do not occur in nature…they are used in precision tools and can cut through diamonds or thick metal.“
Even though laser diodes in devices such as laser pointers are fairly weak, emitting less than 5 mW, they are able to send light over long distances and cause eye damage, even from brief exposure.
LEDs on the other hand are a diffuse source that provide a lesser concentration of light and are used commonly in everyday items such as flashlights, brake lights, etc. They are not considered inherently dangerous in their normal applications.
When the terms LED and laser are used interchangeably, it’s bound to cause confusion leading to misinformation. The most common and harmless wavelengths of light can become dangerous when concentrated into the form of a high-powered laser.
The damage done by this myth is that it can cause regulatory or clinical decisions to be made based on a perceived danger that does not exist when the decision maker does not understand the differences between lasers and LEDs.
There are no dangerous wavelengths associated with Red Light Therapy
A few weeks ago, we came upon a televised interview that was posted on a popular video channel. The topic was whether red light therapy is safe/dangerous and worth the investment. The interviewer was a well-known host and the guest a dermatologist. Here are some snippets from that interview:
Interviewer: Before we get to your concerns, what is red light therapy and how does it work?
Dermatologist: Red light therapy is part of the ultraviolet spectrum towards the end where the wavelengths are quite long and that means they penetrate more deeply into the skin so it can reach right down to the blood vessels down to the fatty layer beyond even where the pigment is produced.
This is utterly and completely untrue. As Scooby Doo would say “Hruh?!”
Let’s take a closer look:
Statement from dermatologist: “Red light therapy is part of the ultraviolet spectrum.”
Except it’s not. Look into any 5th grade science textbook and you are likely to find the following pictograph:
The very obvious spelling mistake is courtesy of the good people at Adobe Stock Images
Red light is way past the UVC, UVB and UVA spectra and is ABSOLUTELY NOT part of the Ultraviolet spectrum of light which looks blue or purple. It is rather surprising that someone would confuse the two. Not to mention that dangerous UV rays are much shorter than red light wavelengths!
To reiterate; a red light therapy panel that has red and/or Near Infrared wavelengths typically emits two types of light; red light which is found between the 600-700 nm wavelengths of the light spectrum and near infrared or NIR which is found between the 800-1100 nm wavelengths of the light spectrum. As can be seen in the graphic above, UV wavelengths span between the 100 and 400 nanometer ranges.
The dermatologist goes on to say that red light should be only administered by a trained professional with equipment that is carefully calibrated, only on the areas needing treatment and not “go blunderbussing everywhere.”
Then she reaches this very arguably mistaken conclusion:
“We know that ultraviolet rays do contribute to increased aging known as photoaging and to skin cancers and other damage so be careful to use just what you need for the condition and not just a for the feel good factor otherwise you could come away red eyed, red faced and in the red with potential major health problems.”
She is wrong about the following points:
- Red light therapy does NOT contain Ultraviolet wavelengths
- Red light therapy panels do not need ongoing calibration
- There is no need for extensive training nor a license or certification to administer Red Light Therapy to prevent adverse events
- Red light therapy has no documented history of causing any type of cancer
- Red light therapy has a long history of anti-aging properties which are well established in clinical studies
- There are no documented cases of Red light therapy causing any types of skin reactions that are similar to sunburn
With this one misconception about which part of the light spectrum red light therapy actually encompasses, one can see how it has led the conversation off a cliff of absolutely unsubstantiated opinions.
Done correctly, red light therapy is safe, and can be incredibly effective
When researching whether red light is right for you or your loved one, it is important to clear up these myths and expose them for what they are. We do of course remind our audience that this is not medical advice, and we recommend that everyone check with their healthcare provider before using red light therapy in order to ensure that it is a good fit.
Be sure to check out our red light therapy devices, all of which have been tested by a third-party lab to demonstrate safe levels of irradiance as well as the safe wavelengths of red and near infrared light.
You can find our lab report right here.
