If you’ve searched online for information about red light therapy, you could easily come away believing it can help almost everything.
Pain. Inflammation. Injuries. Arthritis. Muscle recovery. Skin. Sleep. Brain health. Wound healing. Athletic performance.
The list of claims can become extraordinary.
But there is an important difference between something being studied, something showing promising results, and something being proven to work.
As someone who spent nearly three decades working within the NHS, including clinical research, that distinction matters to me.
I now work within complementary therapy and use red light therapy, more accurately known as photobiomodulation (PBM), as one of the tools available to me.
I am enthusiastic about its potential.
But enthusiasm shouldn’t replace evidence.
So what does the research actually tell us?
First, what exactly are researchers studying?
Photobiomodulation involves applying particular wavelengths of red or near-infrared light to tissue.
You may also see terms such as:
- PBM or PBMT – photobiomodulation therapy
- LLLT – low-level laser therapy
- low-level light therapy
- cold laser therapy
These terms aren’t always interchangeable, and different studies use different equipment.
This is important because one of the difficulties when assessing red light therapy research is that researchers aren’t necessarily testing exactly the same thing.
Studies can differ in wavelength, power, treatment time, dose, treatment frequency, distance from the tissue and whether LEDs or lasers are being used.
They may also be studying completely different conditions.
So asking:
“Does red light therapy work?”
is actually too broad a question.
A better question is:
“Does a particular photobiomodulation treatment, delivered at an appropriate dose, have evidence of benefit for this particular problem?”
That’s a much more useful starting point.
There is genuine science behind photobiomodulation
It is important to establish this because red light therapy can sometimes be dismissed as simply another wellness trend.
Photobiomodulation is a genuine area of scientific research.
Researchers have investigated how red and near-infrared light interacts with biological tissue and how this may influence cellular processes.
One proposed mechanism involves the mitochondria – structures within our cells that play a central role in energy metabolism.
Light absorption by cellular molecules, including cytochrome c oxidase, has been proposed to influence mitochondrial activity and cellular signalling.
Research has also investigated downstream effects involving molecules such as nitric oxide, reactive oxygen species and ATP, the molecule cells use extensively for energy transfer.
But this is where we need to be careful.
Demonstrating a biological mechanism in cells or laboratory experiments doesn’t automatically demonstrate that a treatment will produce a meaningful improvement for a person experiencing pain or recovering from an injury.
Clinical evidence matters.
What about pain?
This is probably one of the areas most relevant to the people who contact me.
The answer isn’t simply “yes” or “no”.
Evidence varies according to the condition being investigated.
For example, a 2024 systematic review and meta-analysis examined photobiomodulation for people with knee osteoarthritis.
Ten studies involving 542 participants were included.
The analysis found a reduction in pain at rest compared with placebo. However, the researchers rated the certainty of that evidence as very low, and improvements weren’t consistently demonstrated across all functional outcomes.
That is a perfect example of why headlines can be misleading.
You could truthfully say:
“Research found that photobiomodulation reduced pain.”
But that leaves out an important part of the story.
A more complete description is:
“Some evidence suggests photobiomodulation may reduce pain in knee osteoarthritis, but limitations in the studies mean we cannot be highly certain about the size or consistency of that benefit.”
I prefer the second version.
It isn’t as dramatic.
But it is more useful.
What about acute injuries?
There is also interesting research involving injuries.
A 2024 systematic review and meta-analysis looked specifically at photobiomodulation for ankle sprains.
Six studies involving 598 people were included.
The researchers reported a significant overall effect on pain and described the evidence for pain as moderate.
However, they didn’t find significant improvements in swelling or function, and the studies varied considerably.
Again, the result is encouraging without justifying a claim that red light therapy “heals ankle sprains”.
That isn’t what the evidence demonstrates.
It suggests photobiomodulation may have a useful role in supporting pain management in some circumstances.
That’s a much more responsible interpretation.
What about sports injuries?
Another 2024 systematic review looked at photobiomodulation in injured athletes.
This is an interesting area because athletes are often looking for ways to recover more quickly and return to training.
Researchers have investigated PBM for pain, recovery and return to sport.
There are encouraging findings, but protocols and evidence vary considerably.
This is why I wouldn’t tell an athlete:
“Red light therapy will get you back to training faster.”
Instead, I would discuss whether photobiomodulation could potentially form part of their recovery alongside appropriate diagnosis, rehabilitation, progressive loading, rest and other professional advice.
Red light therapy shouldn’t replace good rehabilitation.
It may complement it.
Does it improve sporting performance?
This is an area where the evidence becomes particularly interesting – and where newer evidence should make us cautious about sweeping claims.
Earlier research into localised photobiomodulation reported potential improvements in muscle performance and reductions in fatigue under some conditions.
However, a 2025 systematic review looked specifically at whole-body photobiomodulation for exercise performance and recovery.
Only five studies involving 105 physically active participants met the criteria.
None demonstrated benefits for exercise performance or biomarkers of fatigue.
There were some interesting findings concerning sleep, but the researchers concluded that there was no evidence from those studies that whole-body PBM improved exercise recovery or performance.
That doesn’t prove localised PBM has no effect.
It tells us something equally important:
We shouldn’t assume that every form of red light therapy produces the same result.
A large red-light bed, a panel, an LED device applied directly to a muscle and a laser aren’t automatically equivalent interventions.
Why does the dose matter so much?
This is perhaps one of the most important concepts in photobiomodulation.
When you take a medication, dose matters.
Taking 10 mg isn’t the same as taking 100 mg.
Light also has a dose.
The biological response can depend upon factors including:
- wavelength
- irradiance
- energy delivered
- treatment duration
- size of the treatment area
- distance from the tissue
- frequency of treatment
This helps explain why studies can produce apparently conflicting results.
Two researchers might both say they studied “red light therapy” while using quite different treatment parameters.
This also explains why simply buying a bright red lamp online doesn’t necessarily reproduce the treatment used in a scientific study.
I will explore this separately because it deserves an article of its own.
More isn’t necessarily better
This is another important misconception.
If a treatment has a biological effect, it is tempting to assume that doubling the treatment must double the benefit.
Photobiomodulation doesn’t necessarily work like that.
Researchers describe what is often referred to as a biphasic dose response.
In simple terms, too little light may not produce the desired response, while increasing the dose beyond an appropriate range doesn’t necessarily increase the benefit and may reduce it.
That’s why treatment parameters matter.
It isn’t simply:
“Shine red light on it for as long as possible.”
There needs to be more thought behind it than that.
What about inflammation?
You’ll frequently see red light therapy advertised as “reducing inflammation”.
There are plausible biological mechanisms and experimental evidence showing that photobiomodulation can influence inflammatory pathways.
However, inflammation isn’t one single disease.
Inflammation is part of the body’s enormously complex biological response to injury, infection and other challenges.
Sometimes inflammation is part of normal healing.
Sometimes persistent or excessive inflammatory activity contributes to disease.
So I don’t believe it’s helpful to describe red light therapy simply as an “anti-inflammatory treatment”.
The reality is considerably more nuanced.
Photobiomodulation appears capable of influencing cellular signalling involved in inflammatory processes, but what that means clinically depends upon the condition, dose and individual.
What about tissue healing?
Photobiomodulation has also been investigated in relation to wound and tissue healing.
Researchers have explored possible effects on processes including cellular proliferation, collagen production, blood-vessel formation and tissue repair.
There are areas of medicine where PBM has attracted considerable clinical interest.
But again, we shouldn’t take research from one situation and automatically apply it to another.
If PBM influences healing in a particular type of wound under controlled conditions, that doesn’t mean we can automatically claim it will “speed up healing” for every injury.
The body doesn’t work that simply.
So is red light therapy proven?
The most accurate answer is:
For some applications there is encouraging and sometimes clinically useful evidence. For others the evidence remains limited, inconsistent or uncertain.
That may sound less exciting than many red light advertisements.
I think it is actually much more interesting.
Science develops through uncertainty.
Researchers ask questions.
Studies produce results.
Other researchers try to reproduce those findings.
Systematic reviews bring studies together.
And over time we develop a clearer picture of what works, for whom, at what dose and under what circumstances.
Photobiomodulation is still developing within that process.
Why do some studies disagree?
This is one of the questions I find particularly interesting.
Imagine ten studies investigating a tablet.
But one study gives 5 mg.
Another gives 50 mg.
Another gives it once.
Another gives it every day for six weeks.
Another uses a chemically different version.
Then imagine trying to combine all those studies and decide whether “the tablet works”.
Photobiomodulation research can face a similar problem.
Different devices deliver different wavelengths and doses.
Treatment schedules differ.
The populations being studied differ.
Some studies are small.
Some don’t have ideal placebo controls.
And some areas have considerably more research than others.
This variability is one reason responsible interpretation is so important.
Why my NHS and research background influences my approach
I spent nearly 30 years working within the NHS before moving fully into complementary therapy.
Part of that career involved clinical research.
That experience taught me something that has stayed with me:
Good healthcare isn’t about choosing between being open-minded and being scientific.
We can be both.
I’ve personally experienced how valuable complementary approaches can be.
That doesn’t mean I abandon critical thinking when evaluating them.
Quite the opposite.
If I am going to use a therapy with someone, I want to understand what we’re trying to achieve.
I want to know whether there’s a reasonable rationale for using it.
And I don’t want to promise something the evidence cannot support.
That applies equally when I’m working with a person, dog or horse.
Red light therapy is complementary – not an alternative
This distinction is extremely important to me.
If someone develops unexplained or severe pain, significant swelling, weakness, neurological symptoms, a new lump, signs of infection or another concerning change, red light therapy shouldn’t be used to avoid proper investigation.
The same applies to animals.
If your dog suddenly becomes lame, stops wanting to walk, struggles to stand or displays a significant behavioural change, the first priority may be veterinary assessment.
There is a place for complementary therapy.
But complementary means alongside, not instead of.
So why do I offer it?
Because the absence of certainty about every possible application doesn’t mean there is no evidence at all.
There is a growing scientific literature around photobiomodulation, including research into pain, musculoskeletal problems, rehabilitation, tissue responses and other areas.
For the right person – and for the right problem – I believe it can be a useful option to consider.
Sometimes I may use red light therapy by itself.
Sometimes I may combine it with the gentle hands-on techniques I already use.
And sometimes I may decide that neither is appropriate and recommend that the person seeks further medical or veterinary advice.
Treatment should fit the individual.
The individual shouldn’t have to fit the treatment.
Curious whether red light therapy could be appropriate for you?
If you’re experiencing muscular discomfort, stiffness, recovering from an injury or simply wondering whether photobiomodulation might have a place in your recovery, you’re welcome to contact me.
The same applies if you’re considering red light therapy as supportive care for your dog or horse.
You don’t need to decide beforehand which treatment you need.
Tell me what’s happening.
We can discuss what you’re experiencing, what you’re hoping to achieve and whether red light therapy, gentle hands-on therapy, a combination of approaches, or another professional assessment would be the most appropriate next step.
I don’t promise miracles.
I do believe in listening, applying my experience and using complementary therapies thoughtfully.
If you’d like to find out whether red light therapy could be appropriate for you or your animal, contact me to discuss your needs or arrange an appointment.
Photobiomodulation/red light therapy is offered as complementary support and is not a substitute for appropriate medical or veterinary diagnosis or treatment.