Why Bad Marketing Will Kill Red Light Therapy Before Bad Science Does

By Christian Barmen, AriHelder

Something has been bothering me for a while and I think it is time to say it out loud.

Red light therapy is having a moment. If you spend any time online in health, wellness, or fitness spaces, you have seen the ads. Panels. Masks. Wands. And increasingly — blankets. Big, glowing, sleeping-bag-style wraps that promise to bathe your entire body in therapeutic light while you lie back and relax.

I am not here to tell you red light therapy does not work. I have been building these devices since 2017. I use one every single day. The science behind photobiomodulation is real, it is peer-reviewed, and it is growing. I believe in this technology more than almost anything I have worked on.

What I am worried about is not the science. It is the marketing.

The number that is everywhere

Every red light therapy blanket on the market right now leads with some version of the same claim. Over 150 mW/cm². Sometimes 200. Sometimes more. It sits on the product page like a badge of clinical credibility. It sounds precise. It sounds measured. It sounds like proof.

I spent some time this week doing the actual maths on how that number is generated, and I want to share what I found — because I think it explains something important about where our industry is headed.

A typical blanket draws around 115 watts from the wall and covers roughly 11,000 square centimetres of mat surface. If that device genuinely delivered 150 mW/cm² across the whole mat, it would need to draw about 1,650 watts. That is fourteen times more power than it actually has.

The number is not made up. It is real. It is just measured by pressing a sensor directly against a single LED lens, at zero distance, with the device cold. At that one spot, at that one moment, you do get that reading. But that is not what your body receives lying on the mat. Your body receives somewhere around 4 milliwatts per square centimetre on average across the surface.

Four. Not one hundred and fifty.

To be fair — and I think this is important

Before I go further I want to say something that I do not think gets said enough in these conversations.

A red light therapy blanket delivering 4 mW/cm² in a 20-minute session on bare skin actually puts around 5 joules per square centimetre of energy into the skin. The clinical literature on photobiomodulation puts the therapeutic window for surface-level applications at 3 to 50 joules per square centimetre. So the blanket, used correctly — bare skin, twenty minutes — is inside the therapeutic range for skin health, collagen support, and gentle surface recovery.

The product is not a scam. For those specific applications, there is a real case for it.

The problem is that no blanket brand is selling it that way. They are selling it as a full-body recovery device. A tool for muscle repair, joint pain, deep inflammation. And that is where the maths stops working — because near-infrared light at 4 mW/cm² surface irradiance does not survive the journey through your skin to reach muscle tissue at the doses the clinical research requires. A wall panel delivering real irradiance at a real distance puts ten to fifty times more energy at tissue depth in the same session.

The blanket is being sold as something it physically cannot be, for applications the numbers do not support.

And then there is the clothing issue

This is the one I keep coming back to, because nobody talks about it.

Red and near-infrared light does not penetrate fabric. A thin cotton layer intercepts the vast majority of therapeutic photons before they reach skin. This is not a matter of debate — it is basic optics.

Now look at how blankets are marketed. The lifestyle images. The sleeping-bag format. The promise of lying back, comfortable and cosy, wrapped in healing light. Everything about the product experience encourages clothed use. And if you are clothed — the device does not work. At all. You are getting warmth and relaxation, which have their own value, but you are not getting photobiomodulation.

I do not think most of the people buying these blankets know this. And I am fairly certain the brands selling them are not going out of their way to explain it.

Why this matters beyond the product

Here is what concerns me most. And I say this as someone who has devoted years to this industry and genuinely believes in what it can do.

Every overclaimed ad. Every inflated power figure. Every before-and-after photo attached to a product that physically cannot achieve what is implied — these things accumulate. They build a version of red light therapy in the public mind that is part miracle and part magic. And when enough people spend their money and do not get the results they were promised, one of two things happens.

Either they conclude the product does not work. Or a journalist or regulator concludes the same thing on a much larger scale.

Both outcomes damage everyone in the industry. The people doing honest work. The people making genuine devices that deliver real therapeutic doses. The researchers publishing the clinical evidence. All of it gets tarred with the same brush.

We are already seeing more red light therapy ads than ever. What I am not seeing is more honesty in those ads. And I think that is a problem we need to start talking about publicly.

What I am doing about it — and what you can watch this weekend

This weekend I am sitting down to film a proper Q&A on red light therapy blankets. Not a sales video. Not a hit piece on competitors. An honest, evidence-based conversation about what these devices can and cannot do, how to read the numbers on the box, and what questions to ask before you spend your money.

To prepare, I have been going deep on the physics and the clinical research. How irradiance drops with distance. How tissue depth affects dose. What the peer-reviewed literature actually says about the therapeutic window. And as a bit of a thought experiment, a colleague put together a fictional TED-talk-style argument that walks through the three main issues with blanket marketing — and then stress-tested it against the strongest counter-arguments the blanket industry could make.

That process taught me something I think is worth saying plainly: the truth about these products is more nuanced than either the marketing or the critics usually admit. The blanket format has real advantages for certain use cases. It also has real limitations that its advertising never mentions. Both things are true at the same time.

That is what I want to talk about this weekend. Not the clean version. The honest one.

A note on where AriHelder sits in all of this

I am aware that I make a competing product. I want to be transparent about that, because it is relevant.

The Helder 2 is a targeted device. It is built for a different use case — pointing concentrated near-infrared and red light at a specific area of the body for a specific amount of time, at the intensity that the clinical evidence supports for deep tissue applications. It is not a full-body wrap. It does not try to be.

But I did not sit down to write this because I want to sell you a Helder 2. I sat down to write it because I think the people spending money on red light therapy deserve to understand what they are actually buying. And because I think our industry's long-term credibility depends on us being honest about that — even when honesty costs us a sale in the short term.

The technology is real. The market is real. The opportunity is real. None of that requires exaggerating the numbers on the box.

Arjen Helder is the founder of AriHelder, based in Hang Dong, Chiang Mai. The Helder 2 is available at arihelder.com. Questions, challenges, and disagreements welcome in the comments.