Hi! Before jumping into this super long post, I thought it might be helpful to give you some background about myself. I am a doctorally trained social scientist. I work for a non-profit research institute and I design and conduct studies for government agencies–usually focused on the development and testing of risk and health communication messages and designing and evaluating behavior change intervention. My training and love of experimental studies is why I love doing split-face comparisons and before and after testing of skincare products. At my core, I am a researcher who is always curious to dig deeper and investigate things. I love reading journal articles and digging into data to better understand something. So when I started to see people use LED masks a couple years ago I slowly started to look into what they really do. Then, a year ago I was sent the Light Salon Boost Mask by the brand and used it consistently (usually about 3-4 days a week) for the past year. (First- as someone who has NEVER been able to stick with a device consistently, I was very impressed with how convenient and effortless this is to use).
I saw great improvements in my skin, like reduction in redness, quicker healing after breakouts (and one accidental sunburn), and after about 6 months it even seemed like my skin was firmer and wrinkles weren’t as noticeable or as crepey. Even the parentheses around my mouth don’t bug me as much anymore. But this is just anecdotal evidence. Since I couldn’t do a controlled before and after because I use various products to help with my skin, I can’t say those results were just because of the mask (Certainly they aren’t JUST from the mask, but I wanted to feel more confident in saying that I think the mask contributed to those results). To do that I wanted to research the specs of the mask I used, how it compared to other masks on the market, and to research the science behind low level light therapy with LED lights to find out what the research REALLY says.
I noticed that various companies were making some pretty big claims and it seemed like they were claiming that different wavelengths and lights could do a ton of different things–it seemed too good to be true so I wanted to see for myself what evidence was out there. And that brings us to this post.
This started just as a LED mask comparison post, but I will never be able to cover all of the masks that are out there. So the masks included are not the only ones available. But I hope that with the information in this post will empower everyone to use what you know to do your own research. I can’t tell you if a mask is worth it. But I can help you understand how to evaluate masks and to better understand what kind of results you might expect based on what has been found. But it is important to remember that science is a process not a conclusion. So just because there isn’t evidence to support something, doesn’t mean new evidence won’t emerge. But this post will summarize most of what the evidence suggests so far.
I am going to start high level and then go deeper for those that want to really know more.
Low-level laser (or light) therapy (LLLT), also called phototherapy or photobiomodulation (PBM), refers to the use of photons to alter biological activity (Sawhney & Hamblin, 2016). PBM research dates back to the 1960s and has now developed into a therapeutic procedure that is used in three main ways: to reduce inflammation; to promote healing; and to treat pain. Newer LED devices also support a role for photorejuvenation and even hair growth (Lloyd et al. 2018). (Note: It was too much to cover hair growth research for this post. But I hope to write a separate post on that later).
I use it to reduce inflammation, promote healing, and promote photorejuvenation (think of that as a catch-all phrase that captures all the signs and symptoms of skin aging, like skin wrinkling, rougher skin, thin/crepey skin, reduced elasticity [when skin looks saggy], and uneven skin tone.)
At the end of the post I will get into how LLLT works for those that are interested, but the 10,000 foot view is that LEDs emit photons, those light photons are delivered into our skin where it’s absorbed by our cells. When it is absorbed, the cells are photoactivated. Think of it as being energized. With increased energy, every cell, organ and tissue in the body performs better, including your skin. It is like it helps our cells function as if they have had a full night’s sleep and a well-balanced breakfast.
When cells are in a photoactivated state one or more of three things can happen:
- If the cell is damaged or compromised, it will repair itself, or be repaired.
- If the cell has a function, e.g., collagen and elastin synthesis by fibroblasts, it will perform that function more efficiently.
- if proliferation is required, the cell will proliferate.
LLLT is referred to as “low level” because it uses light at lower power densities (<500 mW/cm2)—more on those terms next. (Note that LLLT is different from Intense pulsed light (IPL) or KTP lasers which use MUCH higher power densities. Those lasers also use various wavelengths, but that research shouldn’t be confused with this research because although it may use the same colors they are delivered at very different strengths)
In LLLT, the following parameters are important (in order of importance):
- the wavelength must be correct for the target, with the LEDs emitting a very narrow band around the rated wavelength (e.g., within ±10 nm or so)
- The irradiance (power density) must be adequate;
- The dose (energy density) must be sufficient.
Despite almost 5,000 peer reviewed publications, both in vitro and clinical, LLLT still faces skepticism and has varied findings. The wide range of parameters that can be applied (wavelength, irradiance, treatment duration, and repetition) in some cases has led to contradictory results.
The photobiological response (i.e., how your body responds) is determined by the energy absorption by certain photoacceptors, or chromophores. (Chromophore is the term given to tissue, cellular or subcellular targets for incident light energy at specific wavelengths.). The absorption of photons converts light into signals that stimulate specific biological processes. The most important factor that determines absorption in a biological target (as well as the depth to which the light energy will penetrate) is the wavelength (Calderhead & Tanaka, 2017).
The wavelength is the most important single factor when attempting to achieve a photoreaction, because without absorption, you can’t achieve a reaction (Calderhead, 2018).
Because LLLT works by delivering wavelengths of light into our skin where it’s absorbed by our cells, its effectiveness is closely connected with the amount of light reaching the target tissue (Calderhead, 2016). The right wavelength will ensure absorption of the light by the target chromophore, and to be able to do so at the depths at which these chromophores exist. That is because all tissue targets have an optimum wavelength at which they absorb light (Calderhead & Vasily, 2016). For best effects, the wavelength used should allow for optimal penetration of light in the targeted cells or tissue. Some targets can respond to a fairly broad waveband of 30–100 nm or so, but most of the targets in LED phototherapy are much more specific (Calderhead, 2018).
Wavelengths are often referred to using their associated color and typically include purple/blue (400-495nm), green (495-570 nm), yellow (570-590), orange (590-620), red (620-750 nm) and near infrared (NIR) (750-1200) lights.
Different wavelengths behave differently in the body because they have different chromophore targets and penetration depths (Calderhead, 2007). By targeting the LEDs towards a few very therapeutic wavelengths, maximal absorption is accomplished.
Dr. Tiina Karu (2005) identified peak areas of wavelengths (see figure below) in the 600-900 nm range. This helps to illustrate why wavelengths under 633 will have poor absorption in the skin. Karu and Kolyakov (2005) has clearly shown that there is a “tissue window” for phototherapy between us around 610 nm visible red and 860 nm near-infrared.
Visible light does not penetrate well in the blue, green, and yellow range (400 nm to 600 nm), and are heavily absorbed in melanin in the outer layers of skin (epidermis).
Calderhead (2017) notes “Red light at 633 nm, only 43 nm longer than 590 nm yellow, is less absorbed in melanin and considerably less absorbed in oxyhemoglobin, so penetration is several order of magnitude higher than the 590 nm yellow wavelength illustrated in the photospectrogram, bearing in mind that OD units have a logarithmic value”.
- From the data of over 30 years of LLLT, two wavelengths have been highlighted as having the greatest effect on the action mechanism of skin cells: 633 nm in the visible red, and 830 nm in the NIR (Calderhead & Omi, 2014).
- Red and near-infrared (NIR) lights in particular, are reported to have additional effects in promoting dermal restructuring due to their deeper penetration (Avici et al., 2013; Calderhead & Vasily, 2016).
- In a review on the efficacy of LED-LLLT, Kim and Calderhead (2011) firmly favor the 830 nm wavelength. Stating “at present, the published literature strongly suggests 830nm for all aspects of wound healing, pain, inti-inflammatory treatment and skin rejuvenation, with a combination of 415nm and 633nm for light-only treatment of active inflammatory acne vulgaris. If the wavelength is not correct, optimum absorption will not occur” (and without absorption there will be no reaction).
- Three wavelengths of light that have demonstrated several therapeutic applications are blue (e.g., 415nm), red (e.g., 633nm), and near-infrared (e.g., 830nm) (Ablon, 2018; Kim & Calderhead, 2011; Zheng et al., 2020). (see the end of the post of more information about cautionary information about blue light)
For the most part, you want to look for red (typically 633nm, but somewhere between 630-660nm) and NIR (look for 820-840nm, with 830nm being the gold standard).
- Questions to ask a company: “What are the specific wavelengths used (in nm)? And what is the deviation on either side?”
- For example, the FaceLITE LED mask has LED arrays with a nominal wavelength of 633nm within the range of +- 10. That means that 90% of the photons are at the rated wavelength and will therefore optimally target wavelength-specific chromophores at that wavelength.
Irradiance = power (in W or mW, usually mW) ÷ beam area (cm2) at the tissue surface (not the size of the aperture).
“It is the power density of a beam that will determine more than anything else (apart from wavelength) the magnitude of the bioeffect in the target tissue” (Calderhead, 2018).
In LLLT, the irradiance and wavelength is analogous with the medicine, and the energy density is the dose. If the medicine is incorrect, i.e., an irradiance which is too low (resulting in no effect) or too high (resulting in photothermal damage), no amount of playing around with the dose will achieve the optimum result. (Calderhead & Vasily 2016)
The beneficial effects of LLLT are governed by the Arndt–Schultz law, which says that cells will respond differently to varying levels of irradiance (mW/cm2) or radiant exposure (J/cm2).
Light stimulus will be insufficient to trigger a cellular function if it is delivered below the recommended dose and will inhibit activation of these responses if a dose higher than indicated is delivered.
A higher irradiance often means a shorter treatment time. But a higher irradiance isn’t always better. If the irradiance is too high, the photon energy will be transformed to excessive heat in the target tissue; the mask may get hot and can inhibit the treatment or even create undesired outcomes.
- It has been shown many times that there is a “dose-rate effect” and if the dose is delivered too quickly the beneficial effects are diminished. (Think of it as cooking at turkey at 800 degrees for 10 min rather than 300 degrees for 6 hours. The internal temperature may be the same, but the skin of the turkey will be charred in the 800 degree oven).
- Alternatively, using too low of an irradiance and the photons absorption will be insufficient to achieve the goal. However, the appropriate range of values of irradiance and fluence are not widely agreed upon. One thing to keep in mind is that the irradiance and fluence used in vitro studies are often different from those used in clinical studies. So it is best to draw guidance from clinical studies only (later I provide an overview of some clinical studies focused on skin rejuvenation).
- Many LLLT devices have been commercialized without FDA or other medical regulatory approval because the light output is below a nominal hazard level.
The optimal clinical irradiance is considered to be around 40–150 mW/cm2 (Calderhead, 2018; Sorbellini et al., 2018). Keep in mind that lower irradiance (< 50 mW/cm2) is less likely to induce skin hyperthermia (heat) leading to potential deleterious effects (Barolet et al 2016). Among clinical studies focused on skin rejuvenation, irradiance values ranges from 6 mW/cm2 to 150 mW/cm2, with the median being 55 mW/cm2. A systematic review of at home devices used for nonesthetic purposes (e.g., wound healing, scars, pain, and cognitive function) found that devices finding significant results had irradiances ranging from 8-50 mW/cm2 (Gavish & Houreld, 2019).
- So in my mind, I set 50 mW/cm2 as the upper threshold, because any higher and the mask could be uncomfortable to wear. On the lower threshold, I think 5mW/cm2 is a good bottom value, but I would prefer something closer to 40 since the majority of the studies used 55mW/cm2 (and it also means that it is more likely that I can wear the mask for 10 minutes versus 30 minutes, which some of the masks with the lowest irradiance suggested).
- Questions to ask a company: “Could you tell me the power density of the mask (reported in mW/cm2 or W/cm2)? *note that some companies will even tell you the power density by wavelength. It isn’t uncommon for wavelengths to have different power densities*
Fluence or Energy Density- “The Recommended Dose”
FLUENCE = (IRRADIANCE x .001) x TREATMENT TIME IN SECONDS
Energy density is measured in joules per square centimeter (J/cm2) and is the amount of energy delivered into the tissue. If you ask for the power density and the company tells you the energy density instead, you can calculate the power density by using the suggested treatment time (and converting it so seconds).
- For example, Light Salon recommends 10 min sessions. Their fluence is 18 J/cm2. They report their power density, but if they didn’t here is how we could find it. First, we convert the treatment time to seconds (10*60=600). Then you take 18/600 = 0.03 W/cm2 and multiply that times 1000 to get 30 mW/cm2.
There is no fixed value of fluence that always produces a positive LLLT effect. Even within different studies on the same animal models, there can be contradictory findings. In a meta-analysis of LLLT in wound repair, energy densities from 19 to 24 J/cm2 were found to be more effective than energy densities at or below 8.25 J/cm2 (Woodruff et al., 2004). Among clinical studies focused on skin rejuvenation, fluence values ranges from 1.2 J/cm2 to 126 J/cm2, with the median being 66 J/cm2.
However, the energy density is not the key determinant of the devices efficacy. That is the role of irradiance (Barolet et al., 2016). That is because the same dose (fluence) can be associated with different results based on the irradiance and treatment time (Almeida-Lopes et a., 2001; Barolet et al., 2016). But it is helpful to know what it is to either calculate the power density or to identify the ideal treatment time.
- It has been reported for a continuous wave system that shorter irradiation times with a higher intensity (irradiance) got significantly better results in first passage human gingival fibroblast proliferation in vitro compared with longer irradiation times at a lower intensity, even though the dose (in J/cm2) was the same (Almeida-Lopes et a., 2001).
- Note: You don’t want to know the joule (J), you want to know the J/cm2.
LED Mask Comparison
As I mentioned earlier, I know that the mask in my comparison represent only a small selection of the LED masks available. I tried to include the most popular masks and any masks that I could find information on in the FDA 510(k) database. I also only focused on face masks, versus hand held devices or panels because I had to narrow it down somehow and since I enjoy using the mask bc of its convenience that is what I focused on. But the same research that applies to face masks applies to those devices, so you are able to assess their potential efficacy using the parameters above.
If you come across a mask that you are curious about, I recommend identifying the wavelengths used, the irradiance and the treatment time. Then you can compare those specs with this list to see how it stacks up.
- TIP: when it comes to skincare devices I highly recommend the following google search “accessdata.fda.gov [name of device]” – if you are lucky you will be able to find the 510(k) document that often contains specs that the company doesn’t always openly reveal. For masks sold in the United States, very few manufacturers have received FDA approval and have gone through this process (I have linked the ones that I found below). As Calderhead (2018) states, “some less than truthful manufacturers will claim FDA approval, when in fact all they hold is a letter from FDA recognizing that their LED system is a nonsignificant risk device, or NSRD. This is NOT the same as a system’s having gone through the due regulatory process to obtain what is known as a 510(k) approval showing significant equivalence to another system with prior approval based on which, and only on which, can that device be legally sold in the USA for clinical use” (p.326).
- On that note, “I-smart marketing LTD” submitted a 510(k) premarket notification of intent to market the FaceLITE device using “Shape B” (the same shape that Light Salon and CurrentBody use) and received approval. That approval was then applied to the 6 other masks all made by the same manufacturer. At some point FaceLITE updated the design of the mask (which I have labeled “Shape A” in my graphics). It has more lights but FaceLITE (the manufacturer) emphasized that it still had the same irradiance. Here is where you can see all of the devices approved under that 510(k) approval and made by the same manufacturer: link
- TIP: one huge benefit of flexible LED masks (versus hard ones) is that you can lay it on your chest or hands. I even lay mine on my abdomen to help fade an appendectomy scar. I also love how silicone masks lay flat are easier to store (and take up less space). Plus it’s easier to take it with you when you travel.
In my humble opinion, the ideal mask has: evidence-based wavelengths (633nm; 830nm) with precise values (instead of wide ranges), there is transparency from the company as to what the irradiance is (and the irradiance is closer to 50mW/cm2 than it is 5mW/cm2), it has a comfortable fit that doesn’t require being plugged in (because let’s be honest, if it isn’t comfortable and convenient you won’t use it as often!), AND ideally it has a 2 year warranty. RE: the warranty. A couple lights went out on my LED mask right after the 1 year mark and that is totally covered by the warranty. In my mind, the warranty helps to justify some of the price because some masks may be cheaper but they may stop working after a year and you would have to repurchase!
Note: some of the links below are affiliate links where I will earn a commission from your purchase. This does not impact your cost. Posts like this take me a ton of time, so I appreciate your support if you do choose to shop through my links.
The first image below shows all the masks. Note that the numbers in the image (1-18) don’t really reflect a ranking of preference. BUT I did put the ones with the best specs (in my opinion) in the top 10 (but within the top 10, it isn’t in order–I grouped by mask design/shape). And then from 11-18 I again grouped by shape but I put did try to order them a bit based on putting ones that used the ideal Red and NIR wavelengths above ones that didn’t. But my goal with this post was never to tell you what MY favorite was. It was to arm you with information to decide which is best for you.
After the initial image, the next is a key for the text that follows and then I show a breakdown of 7 masks (one of which is the Light Salon Boost mask that I’ve used since Nov 2020) all made by the same manufacturer with the same specs (with some slight deviations) and all approved under the same 510(k) application. They are functionally equivalent but I’ve highlighted a couple things outside of their specs to consider. If you were to ask me which mask to choose, because of my preference for flexible, silicone masks I would suggest choosing one of those 7–with the Omnilux, FaceLITE, and Light Salon being my top choices.
Here is where it gets complicated….the Omnilux provided evidence of a higher irradiance (41 mW/cm2 to be exact, but they officially state 30 mW/cm2 if asked… I think they might be required to as that is the irradiance reported by the manufacturer??). Knowing the Omnilux was tested at 41 mW/cm2 gave it a slight edge in my mind. BUT since the four “Shape A” masks are all manufactured by the same company, I am very confused as to what the means for the other masks (FaceLITE, Deesse, SkinLite). For example, I wonder if the other companies using the masks conducted independent tests would they also find ratings of ~40 mW/cm2? I honestly don’t know. But when I told FaceLITE that Omnilux reported a higher irradiance they said that was incorrect. But Omnilux was very transparent and showed me their testing results… So I will just be honest when I say I am confused. I wish I had an answer for you! But I’m happy that Omnilux had the 41 mW/cm2 irradiance.
*Just another reminder that these are not in order of preference–see note above**
- Light Salon Boost Mask: ($495 / £329) This is the mask that I have used for over a year (since 11/2019. There is a typo in the image). I was sent the mask by the brand to try (with no string attached) and I love it. This may sound silly, but the strap on top really helps improve the fit, so I like that they include it. Plus their website (and Instagram account) have the MOST amazing FAQ section. Super helpful if you have questions about the mask. That being said, if you live in the US, because of the exchange rate (they are based in the UK), this one may end up being pricier than some of the other ones that are identical to it (i.e., CurrentBody) or nearly identical (PRIORI). However, you can often find it on sale. (@my.sister.made.me.buy.it is great about finding and sharing deals!)
- I have a 20% off affiliate coupon code at the thelight-salon.com. (GOALSTOGETGLOWING20) that brings the cost down to £263 + £25 shipping (if you are in the US). Here is the way to figure out the current exchange rate (as of today, it is $396 including shipping).
- Is also Available at Bluemercury or Verishop for $495 (and they sometimes have coupon codes that will work on it).
- Also available sometimes available at Nordstrom (but often out of stock)
- Bloggers that use the mask so you can look for their reviews: @voisual (she has used it for 2 years); @tales.of.skincare, @canuckbeauty, @myglowtos, @glowwithjules, @adeolagboyega, @makeupwithdrawal, @gothamista (Ꮢenée also has a fantastic YouTube review)
- CurrentBody Skin LED Light Therapy ($399): I would get the additional head strap on Amazon to help with fit. (Here is the one that a follower recommended)
- Available at CurrentBody.com (currently on sale for $355).
- Also available on Amazon (currently $365).
- @thewayofthesnail, @imoisturizeitdaily , @sabrinadoesbeauty, and @natalieasmyth have this mask
- PRIORI Unveiled: ($395 but 25% off with code VANESSA making this $296). This one has a slightly updated light layout from the Light Salon and Current Body (but the same irradiance). This also doesn’t have the strap on top, so you may want to buy that to improve fit.
- Omnilux Contour ($395): While doing my research, I noticed that Omnilux conducted the most clinical trials out of all of the companies (granted, they weren’t using this specific mask, but I appreciate that they conduct those trials). When I was talking to the brand about their key parameters they offered to send their face mask and glove (I am very excited about the hand mask because now I can just use that on one hand and see if there is an improvement from the left hand. Finally a clean comparison!) I am glad that I got to try this one because it enabled me to see how the slightly different shape impacts fit. This shape is designed to be a better fit for healing post cosmetic procedures but there isn’t a huge difference in coverage (just a couple centimeters — I took some photos that I will include). I like how this one gets a little closer to the jaw line because of the strap arrangement, but I do find the Light Salon slightly more comfortable and quicker to get on. But it is super minor difference. This one (and the other masks that I labeled as having “Shape A”) all have slightly better coverage of lights on the upper forehead, so I prefer Shape A or Shape B (but that is getting nit picky). Let’s imagine a scenario where I had never tried the light salon mask or any LED mask for that matter. After writing this blog post and doing all this research and balancing practical things like wanting a flexible mask versus a hard mask (which is totally personal preference, but I find it to be more convenient and versatile), out of the flexible LED mask options I would pick Omnilux because it is the most affordable (after coupon code) out of the “Shape A” masks.
- Available at omnilux.com and the code VANESSA10 saves 10% making it $355 (free shipping)
- I just received this mask so I will be sharing my thoughts on it in the future!
- FaceLITE ($350 + $17 for shipping): FaceLITE hasn’t launched their US website yet, but you can DM @honeyanddewskin (who is my friend and is an esthetician) and she is selling them for $350+$17 shipping
- FDA 510(k) approval document
- You will notice in the 510(k) document the LG BEAUTY LED MASK was used as the predicate device (that is how I initially got the specs of the LG Mask! 🙂 ) You can see that since the LG Beauty Mask doesn’t have to have the EXACT same specs to be deemed “substantially equivalent”
- @andymillward_ uses this and has a number of posts on his page. Wayne Goss also has reviewed this on YouTube. (Note that both are using the original shape: “Shape B” as I call it.
- FDA 510(k) approval document
- Déesse Express ($486): The one thing different about this mask compared to #4-6 above is that is has goggles that can be attached. This is new and I couldn’t find it for sale on its main website, but I found it here: dermacaredirect.com
- SkinLite ($449): I would pass on this one because the Omnilux Contour and FaceLITE are identical but cheaper. Available at dpderm.com
- Boots No7 Age Defying LED Mask (£150): This is not available for those in the states. One downside of this one is that I couldn’t find out any warranty information on this. So, while it is cheaper than the other flexible masks, if it breaks after a year you end up buying it again and the cost savings is gone. I was happy to see this had a good irradiance and used Red and NIR in the right wavelengths (and that the company disclosed it… but that was hard to find, it was in a Facebook post comment that they replied to and my friend found while I was digging for that information). But if you have access to it, this could be a great, more affordable option.
- SpectraLite FaceWare Pro (Dr Dennis Gross) ($435) – I think this is a good one but the two things I wonder about this one is why they included 605nm (yet I am happy to see 630nm) and why they went with 880nm instead of 830nm (Especially since max absorption has been found for 820-840nm. It’s not that 880nn can’t be effective, it just struck me as odd). But this has great irradiance which means you can use it for shorter treatment time (3 min). I have heard the complaint that the strap breaks and then you have to hold in up (or lie down with it on) and I believe Caroline Hirons noted that this is too small for her face. So in terms of the hard style masks, you can look and see if there are some that have larger dimensions in my chart. For this one, I would personaly focus on using the setting that uses red and near infrared lights rather than consistent use of their settings with the blue light (more info on some things to consider with blue light is provided at the end of the post).
- FDA 510(k) premarket notification: Here and here (this one included the 415nm)
- This one is available LOTS of places. So it could make it easier to find a good deal. Sephora; Dermstore; SpaceNK
- @kathleenjenningsbeauty and @snoo_skincare and @hk.skincare.makeup.fashion use this. @makeupwithdrawal has this one and the Light Salon and this post compares them
- LG PRA.L DERMA LED MASK ($540): This one’s parameters are pretty good (this is the mask that FaceLITE used as the predicate device in their 510(k) submission. In terms of where to buy it, it can be a little hard to find. But right now it is available on Amazon.
- OPERA Lebody ($650) Available on lebodyusa.com or on amazon which sells it for $709 but it currently has a $150 coupon making it $559;
- irradiance found via 510(k) document
- MZ Skin Golden Facial Treatment Device ($625): This one has a lot of unnecessary wavelengths and it doesn’t include NIR and it has to be plugged in to use. Not one I would use. Currentbody has this on sale for $465 right now (25% off); Available at Verishop (currently has a sale for 15% off with code BESTYOU); also available at Revolve.com
- Déesse Pro Mask ($1,900): Can be found here. This is a mask that has focused on the highlighting the large number of lights… but looking at the key parameters it has a much lower irradiance than I had anticipated. Also, IMHO this gets points knocked off because it is so expensive and it has to be plugged in while wearing it (which I personally find to be an inconvenience but I guess that depends on where you have power outlets to plug in to!)
- Aduro 7+1 LED Face Mask ($395): Currently on sale for $319. Can be found here. I am turned of by the claims that this one makes about the various colors it includes. Plus because this has a lower irradiance it is also recommended that you do longer sessions more days a week.
- Eco Face Near-Infrared LED Mask ($233): You can get it in white: Amazon or gold: Amazon. Gothamista reviewed this one in the previous YouTube video I linked to (TLDR: she liked it but she liked the Light Salon better). I was sad to find out they won’t reveal their irradiance. But I guess one bonus is that they provide some white paper results (which should be taken with a grain of salt but they are better than nothing.)
- Project E Beauty Skin Rejuvenation Photon Mask ($110): This one has the shape and style that is found all over Amazon. It’s interesting that the irradiance of this is SO different front the Dermashine because I was wondering if all of these look alike masks would have the same irradiance (and were just the same mask, rebranded). But turns out that isn’t the case! So that’s a big lesson to not assume two masks would have the same irradiance if they have the same wavelengths, number of lights, and look identical. One big downside of this mask is that it doesn’t have NIR. And it was a red flag for me that they use 390nm which researchers have cautioned to avoidSerrage et al., 2020) (Found on Amazon
- DERMASHINE Pro 7 color LED Mask ($118): I appreciate how helpful and transparent the contact at Dermashine was… but I was shocked at how low the irradiance it (I actually thought it was a typo so I confirmed it was 0.5mw/cm2). This is why you really want to find out the irradiance before buying! Also it uses a bunch of wavelengths that have little to no evidence to support them and it doesn’t have NIR.
- Cellreturn LED Platinum ($2100): Very expensive mask and the company is very guarded about the wavelengths and power. I found two journal articles that provided some information but otherwise the company declined commenting. The odd thing is that the parameters provided in the journal articles were not ideal. They didn’t provide the irradiance but they provided the fluence, and using that to calculate the irradiance gave a shockingly low number (1.5 mW/cm2). Also I couldn’t confirm if the wavelength of the NIR was 760-900 or if it had a more narrow band. This matters because research has found that wavelengths between 700-770 have been reported to not have any significant activity (Gupta et al., 2014; Karu, 2010; Wu et al 2012). Despite the low irradiance, a recent study by Kim et al 2020 found some positive outcomes.
- DMH Aesthetics LED Light Shield Mask ($190): I wish I could show you how many people I was passed around to in this company trying to find out the irradiance. In the end they said they declined telling me… the whole thing rubbed me the wrong way. Poosh sells it among other places. In addition to not revealing the irradiance, this has wide wavelength bands and it overlaps with wavelengths that are not ideal. For example, the “red” wavelength goes from 620-750nm–that is extremely wide range. Not saying this won’t produce results, but it is one that I am extremely skeptical of.
Tips for buying a mask
The goal is to avoid a mask that fails to deliver the power, penetration, and clinical benefits claimed by the manufacturers.
How can you avoid wasting your money? Aim to purchase products that use evidence-based wavelengths and that report all key parameters. (Also, this isn’t mentioned below but take into consideration convenience. Because these products only work if you use them)
- Does the mask manufacturer provide the specific wavelengths?
- If no, I would pass. This should be the bare minimum requirement.
- Does the device use precise wavelengths (e.g., 633nm) versus wide ranges of wavelengths (e.g., 620-750nm)?
- Ask what the nominal wavelength of the system is, and what is the deviation either side.
- If the device has an imprecise wavelength, then that means you aren’t getting as pure or high quality a light.
- The higher the grade of the LED, the narrower the bandwidth of the emitted photons, allowing LEDs to emit the rated wavelength plus or minus a very few nanometers.” (Calderhead & Vasily, 2016).
- A difference of even 5nm from the peak can in some cases dramatically lower the action potential” (Calderhead, 2018)
- Does the mask use wavelengths with published scientific evidence showing it’s effectiveness?
- Some companies like to highlight the number of wavelengths used, but often those additional wavelengths have very little or no published work to back up the claims of the manufacturer (and they seem more like a marketing gimmick than anything), and a careful consideration of the wavelength/penetration ratio will rule out many of the shorter visible light wavelengths” (Calderhead, 2018)
- If the goal is overall skin rejuvenation (including reducing inflammation and speeding up healing), choose a mask with NIR (ideally 830) as the literature has consistently found that this wavelength targets a larger number of the necessary cell types and has a better effect on the overall skin rejuvenation process than other wavelengths (Kim & Calderhead, 2011).
- Keep to well-proven wavelengths, applied singly unless they are the well-tested combinations. Karu and Kolyakov (2005) have pointed out that there are many pairs of wavelengths which actually inhibit cellular activity when used together, yet enhance activity when applied separately. So unless it is Red and NIR, Red and Blue, or NIR and Blue, you may want to just use different colors separately.
- If it uses Blue light, the best choice is 415nm. And 415nm appears to be best and many recommend using it in combination with red or NIR (but blue +red has more evidence).
- Does the company report the irradiance (or will they tell you if asked)?
- Devices with extremely low irradiance probably won’t have any determinantal effects, but they can be a waste of money and time.
- You can email companies and ask them to tell you the irradiance (or power density) reported in mW/cm2. If they only report the J/cm2 you can calculate the mW/cm2 using the recommended treatment time (in seconds).
- Any manufacturer of an LED device should understand how power density (irradiance) is important when making and use LED devices. Therefore, if they don’t share the data it would make me suspicious as to whether they know the irradiance or if there is some reason they don’t want to share it. It is not that the device won’t be effective, it is just that you really won’t be able to gauge whether it is comparable to masks that have been found to be effective. Also, you won’t know what you are working with and you may be wasting your time and money using the device.
Mechanism of action of LLLT
Ok if you want to know even more about the mechanism of action, this section is for you!
The “photobiomodulation zone” comprises cells which have absorbed the incident photons, directly or indirectly transferred the photon energy to the cells’ own energy stores, becoming photoactivated (Calderhead, 2018). The light energy helps to enhance our cellular potential (helping our cells to function more efficiently), promote oxygen utilization within the cell, and generate cellular fuel (or ATP) (Barolet, 2018; de Freitas & Hamblin, 2016; Hamblin, 2016).
Photobiomodulation stimulates fibroblast proliferation, collagen synthesis, growth factors, and extracellular matrix production by activating cellular mitochondrial respiratory pathways (Ablon, 2018). Therefore, LED light therapy aids skin rejuvenation through increasing collagen production and decreasing collagen degradation (which can be seen with the tightening of lax skin and the reduction of wrinkles).
- LED light therapy is thought to improve tissue function
- helping mitochondria produce more energy (i.e., improved energy metabolism)
- decreasing inflammation
- helping build the cell defense systems to increase resiliency.
Red and Near infrared (NIR) have a number of different mechanisms of action, but two main ones involve:
- enhancing cellular mitochondrial function and ATP production through interacting with a photoreceptor called cytochrome c oxidase. Mitochondria are the energy-producing units of our cells. Think of them as the batteries that fuel all the processes of our organs. Enhancing the mitochondrial function translates into more cellular energy inside the cell, which allows the cell or organ (e.g. skin) to work optimally. When red and near-infrared light photons reach the photoacceptor cytochrome c oxidase, it helps the mitochondria use oxygen more efficiently to produce ATP.
- Building up the cell’s antioxidant and anti-inflammatory and cell defense systems by creating a low dose stressor that the body then adapts to by becoming even stronger (known as hormesis).
Through these mechanisms, LLLT is thought to help increase the skin’s ability to resist the photoaging processes.
Skin rejuvenation is strongly linked to the wound healing process. For example, to repair damage from UV rays, your skin needs to be able to repair cellular and DNA damage (which is similar to what it does during wound healing). Red light can help this process because it stimulates collagen synthesis and fibroblast formation, anti-inflammatory action, energy production in mitochondria, and DNA repair (Barolet, 2018; de Freitas & Hamblin, 2016; Hamblin, 2016).
This next figure from Kim and Calderhead (2011) further illustrates the confirmed mechanisms of action for the three main endpoints of 830 nm LLLT (633 nm has beneficial effects as well), namely wound healing, the anti-inflammatory response through acceleration and quenching of the post-wound inflammatory phase and pain attenuation.
The main benefits seen in clinical trials of LLLT for skin rejuvenation are:
- improvements in skin tone
- improvements in radiance
- improvements in texture
- reduction of wrinkles and fine lines
- increased elasticity (less evidence for this compared to the the above benefits)
Biopsies have shown increased collagen and elastin production that would account for many of these benefits.
I have focused this review on skin rejuvenation, but there is a huge body evidence looking at LLLT on wound healing and reducing inflammation. Here are a few snippets:
- Reduction in inflammation due to light therapy is one of the most accepted LLLT effects (Lopes-Martins et al., 2007).
- LLLT has been also effectively used in “wound healing applications following surgical aesthetic and resurfacing procedures, post-procedural erythema, and in conjunction with photodynamic therapy” (Ablon, 2018)
- Trelles and Allones (2006) found applying red light (633nm; 80mw/cm2; 96j/cm2) after laser resurfacing cut healing time in half. Later studies by Trelles and others found 633nm (82 mW/cm2; 98J/cm2) and 830nm (46mW/cm2; 55 J/cm2) improved post procedure wound healing.
Some other interesting applications that still have very little research on them were outlined in Barolet (2008).
- “If LED therapy is administered several times prior to a UV insult, a mechanical trauma such as a CO2 laser treatment or a surgery, one may prevent undesirable consequences such as sunburn, postinflammatory hyperpigmentation (PIH), or hypertrophic scarring, respectively.” Barolet goes on to talk about those applications here. For example, Barolet (2008) reported that the use of LED 660 nm therapy can prevent or treat PIH, help with sunburn prevention.
In “Part 2” of this blog I want to summarize all of the growing areas of research because there were far more that I couldn’t cover in one post.
The main risks that have appeared in clinical trials were minor and self-resolving and include (Jagdeo et al., 2018)
- erythema (in high power densities)
- hyperpigmentation (in wavelengths under 600nm)
- ocular symptoms (typically with blue light)
Risk Mitigation Strategies
- use protective eyewear
- discontinue sessions if any side effects occur
- limit the number of treatment sessions
Light irradiation with low power density has been reported as a noninvasive, non-carcinogenic, atraumatic, with no known side effect therapy to many diseases and undesired conditions. Typically, there are no safety concerns for LEDs unless they are blue or if the device uses a very strong power (>100 mW/cm2).
“Caution must be emphasized especially for epileptic and photophobic patients especially if LEDs are pulsed.” (Barolet, 2008).
If you are using a blue light, it is advised that you use eye protection.
“Whilst the perceivable dangers of LLLT are mainly related to retinal damage (both clinician and patient) and skin burn (mainly related to shorter UV wavelengths), the safety of LLLT is well documented in a number of standards such as US Code of Federal Regulations, American National Standards Institute and the International Standards Manual, and other laser safety books and review articles [21, 22]. This includes ‘The Guidelines for Skin Exposure to Light’ in the International Standards Manual (IEC-825) which states that an exposure of less than 200 mW/cm2 is safe, and the marketing and the use of therapeutic LLLT is approved by the Food and Drug Administration. Preventative measures such as safety googles should always be utilized to minimize any risks and therapeutic devices may utilize high-powered light sources (>500 mW) may be spread over larger areas to fall within the recommended irradiance exposure limits.” (Hadis et al., 2016)
Things to keep in mind
- Many companies cite evidence from in vitro or animal studies. While those studies can be useful, it is important to note that studies that examine the effect of LLLT therapy tend to find a much larger effect in animal studies than in humans (e.g., Woodruff et al., 2004)
- Comparisons of findings among studies of LLLT is greatly complicated by use of different wavelengths and dosages. Different wavelengths (e.g., 904 nm, 780–860 nm, and 890 nm) have produced conflicting results.
- Best results are not seen immediately post treatment, but later on at 4, 8 and 12 weeks or more after the final treatment.
- Green and yellow light have very poor penetration into living tissue and have rarely been studied. Some of the limited studies using yellow light were not able to be replicated by different researchers. So take claims about the benefits of green, orange and yellow light with a grain of salt. Although a more recent in vitro study by Chen at el (2018) offers very preliminary evidence that LLLT with yellow light at 585nm can help reduce pigmentation. So I would be more likely to take a chance on yellow light than green at the moment (though I would still look for a mask that offers red and NIR and has a yellow setting that can be used by itself because combinations of yellow and red or NIR have not been tested and the combinations may inhibit cellular activity (more on this below).
- Notes on Blue Wavelengths
- If you go with blue light, 415nm is the ideal wavelength.
- If you are using blue light to treat acne, it may be best to use a handheld device to just target spots as there is some evidence that it could increase hyperpigmentation.
- Blue light has poor penetration into living tissue, but the 415nm wavelength is beneficial for the treatment of acne.
- The term “blue light” can refer to a relatively wide range of wavelengths from violet (390–425 nm), indigo (425–450 nm), royal blue (450–475 nm), blue green (475–500 nm)–and they have had very different results.
- Some studies of using a wavelength of 420-443nm found that unintentional increases in hyperpigmentation (as reported in Jagdeo et al., 2018: Weinstabl et al 2011; Kleinpenning et al 2010).
- “The use of blue light in particular (400–500 nm) is additionally surrounded by significant controversy relating to the premise that the margin between ‘safe’ blue light and potentially damaging ultraviolet (UV) light is not well defined.” (Serrage et al., 2020)
- In an animal study, Blue light (430–510 nm) delayed the barrier recovery, whereas red light (550–670 nm) accelerated it Green light (490–560 nm) and white light (400–670 nm) did not affect the barrier recovery rate (Denda & Fuziwara, 2008).
- 415nm has been found to be beneficial for the treatment of acne (inflammatory lesions respond better to blue light than noninflamatory lesions like whiteheads and blackheads).
- Inflammatory acne lesions contain bacterium, P. Acne, which has porphyrins–415nm is the optimal wavelength for porphyrin absorption. Irradiation with a wavelength of 415nm can destroy the P.acnes but it doesn’t address the associated inflammatory problem. The combo of 633nm red light and 415nm blue light is recommended because the red light also tackles inflammation and appears to improve the efficacy on noninflammatory lesions (Greaves et al 2015).
- Wearing eye protection with blue light is strongly recommended
- “The use of wavelengths in LLLT at 400nm or lower should be utilized in practice with extreme caution.” (Serrage et al., 2020)
- Wavelengths shorter than 600nm tend to scatter, rather than to penetrate deeply into the body tissues
- May be best to avoid wavelengths between 700 and 780 nm as they have been found to be rather ineffective as it coincides with a trough in the absorption spectrum of cytochrome c oxidase. In studies involving mice, wavelengths between 700-770 have been reported to not have any significant activity (Gupta et al., 2014; Karu, 2010; Wu et al 2012)
- Wu et al (2012) used a 730-nm laser on TBI in mice and found it to be ineffective while 660 and 810 nm lasers were effective. Gupta et al (2014) carried out a similar comparison on wound healing in mice and again found that 660- and 810-nm lasers were effective, while a 730-nm laser was not effective.
- In a meta-analysis of of low-power lasers in tissue repair and pain control (Enwemeka et al., 2004), 633nm had the largest effect size and 780 had the smallest.
- Evidence has been also reported indicating the higher efficacy of the combination of different wavelengths in LED therapy than monotherapy (Opel et al., 2015; Jagdeo et al 2018). But Karu and Kolyakov (2005) have pointed out that there are many pairs of wavelengths which actually inhibit cellular activity when used together, yet enhance activity when applied separately. “Light energy represents information for cells, and then they act on that information. Imagine a cell receives receiving conflicting information from two different wavelengths: one tells the cell to “turn right” and the other to “turn left”. At best the cell will be confused and do nothing. At worst, it will shut down partially or completely. Unless there is a specific reason based on photobiological knowledge, one wavelength at a time should be the order of the day in LED phototherapy.” (Calderhead, 2018)
Hope this was helpful! I produce this content for free, but if you found this helpful & would like to support my work, here is my Venmo: @Vanessa-BP
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