Red light therapy has had an unusual journey.
For years it sat quietly in clinics under names most people had never heard, including low level laser therapy and photobiomodulation. Then it arrived on social media, got attached to a long list of claims, and became something people buy panels for.
Which has left it in an awkward position. There is a legitimate clinical use for it, and there is a great deal of marketing wrapped around it that goes well beyond what anybody can actually support.
So here is a straightforward account of what it is, what we use it for, and what it is reasonable to expect.
What it is
Red light therapy involves exposing tissue to specific wavelengths of red and near infrared light.
The light is not hot. That surprises people, who frequently expect something like a heat lamp. A proper device may feel slightly warm, and the effect is not thermal.
The light is also not ultraviolet. There is no tanning effect and no burning.
What is being delivered is light at particular wavelengths, at a particular intensity, for a particular length of time. Those three things together are the dose, and they matter considerably more than most of the marketing suggests.
How it is thought to work
The explanation most commonly given involves the mitochondria, which are the structures inside your cells that produce energy.
The proposal is that certain wavelengths of light are absorbed within those structures, and that this influences cellular energy production and a cascade of other effects, including changes in inflammation and circulation locally.
It is a plausible mechanism and it is reasonably well described.
It is also worth being clear that the mechanism being plausible does not automatically mean every claimed benefit follows from it. A great deal of what gets marketed under red light therapy extrapolates from the mechanism rather than from any evidence of the specific effect.
Where it is used in a clinic like ours
We use it as an adjunct, which is the honest framing.
That means alongside the hands on work and the exercise, rather than instead of either.
The situations where it has a reasonable place in musculoskeletal care include soft tissue pain and irritation, tendon problems, and areas of persistent muscular tightness and sensitivity. It is frequently used to make the other work more tolerable, particularly when an area is too sensitive to treat comfortably.
What it is not, in our hands, is a standalone treatment. Nobody comes here, lies under a light, and goes home expecting that to have fixed the problem.
The thing that changes a musculoskeletal problem is usually some combination of addressing the mechanical cause, restoring movement, and building capacity. Anything that makes that process more comfortable or more productive is useful. Nothing replaces it.
What a session involves
Practical, because people ask.
The device is positioned close to the area being treated, usually a few inches away, or placed directly against the skin depending on the device.
Skin needs to be exposed. Light does not meaningfully penetrate clothing.
Sessions are generally short, in the region of several minutes per area.
You will usually be given eye protection, and you should use it. Looking directly into a high output device is not sensible.
What it feels like is very little. Mild warmth at most. Some people find the sensation pleasant and some notice nothing at all.
And it is not a one off. Where it is used, it is typically used across a series of sessions rather than once.
What is reasonable to expect
This is where we would rather be straight with you than enthusiastic.
Reasonable expectations include some reduction in local pain and sensitivity, and an area that is more comfortable to work on and to move.
Unreasonable expectations include a cure, a permanent fix, or an effect that holds without the rest of the plan.
The honest position on the wider evidence is that it varies considerably by application. There is more support behind some uses than others, and the gap between the best supported uses and the most heavily marketed ones is substantial.
If somebody tells you it will resolve your problem on its own, that is a reason to be cautious about everything else they say.
The claims worth being skeptical about
Red light therapy has become attached to a remarkable number of things.
Weight loss. Hair growth. Hormonal effects. General wellness and energy. Anti aging in various forms. Improved sleep. Detoxification.
Some of those have been studied in some form. Many have not, or have been studied poorly, and the leap from a plausible cellular mechanism to a specific whole body outcome is a large one.
As a general rule, the further a claim gets from a local effect on the tissue the light is actually reaching, the thinner the ground becomes.
And a practical point. Light does not penetrate very far. Claims about deep structures, internal organs or systemic effects should be weighed against the simple question of whether the light is physically reaching the thing being described.
Dose matters, and more is not better
Something the consumer market tends to get wrong.
There is a reasonably well recognized idea in this field that the dose response is not a straight line. Too little does nothing, and there appears to be a range where an effect occurs, beyond which more does not add benefit and may do less.
Which means longer sessions and more powerful devices are not automatically better, and the assumption that you cannot overdo it is not a safe one.
It also means that the specifics of what a device delivers, at what wavelength, at what intensity, for how long, actually matter. A device that looks similar to another may be delivering something quite different.
Who should not use it
Worth stating, and worth asking about before you start anything.
Caution or avoidance applies with active cancer or over any undiagnosed lump or lesion, during pregnancy particularly over the abdomen, over the thyroid, directly over the eyes, in anybody with photosensitivity, and in anybody taking medication that increases light sensitivity, which includes certain antibiotics and other common drugs.
If you take regular medication, mention it. Photosensitizing drugs are more common than people realize.
And if you have any skin lesion you have not had checked, get that looked at before shining anything on it.
The question to ask any clinic
If red light therapy is being offered to you, a few reasonable questions.
What specifically are you hoping it does for me?
Is it being used alongside other treatment or instead of it?
How many sessions, and how will we know whether it is helping?
And what happens if it does not help?
A clinic that answers all four clearly is giving you what you need. A clinic that describes it as the treatment rather than as part of one is overselling.
Our position
We use it because it is a useful addition for certain presentations, it is low risk when used appropriately, and it can make the rest of the work more comfortable and more productive.
We do not present it as the thing that fixes problems, because it is not.
What fixes problems in this field is usually finding out what is actually driving your symptoms and then doing the work on it. That tends to involve hands on treatment, movement, and building capacity over a period of weeks.
Anything that supports that is welcome. Nothing substitutes for it.
When to see a doctor rather than book a session
Pain following significant trauma, pain with fever or feeling generally unwell, unexplained weight loss, progressive weakness or numbness, severe unrelenting night pain, any history of cancer with new pain, or any new or changing skin lesion.
Those need medical assessment rather than any form of treatment aimed at symptoms.
Start with finding out what is wrong
Whatever is or is not included in your treatment, the useful first step is an assessment that establishes what you are actually dealing with.
Castrell Neuromuscular Therapy offers a free discovery visit at no cost and no obligation. You will get a thorough assessment, an honest explanation of what is driving your symptoms, and a clear account of what we would recommend and why, including where any additional modality fits and where it does not.