Red light therapy: a doctor’s approach

What the evidence shows and does not, how it works, whether it is safe, home device versus clinic, how I use it in clinic, and where this modern therapy meets older traditions of healing with light.

Key takeaways

Red and near-infrared light help your cells make their own energy, move more blood and heal faster. No drugs, no ultraviolet, barely any heat.
The honest picture is mixed overall, but strong for skin, hair, pain, fibromyalgia, cognition and recovery, promising for mood and the ageing brain, and oversold almost everywhere you look.
It all makes more sense once you stop seeing light as just a treatment and start seeing it as a nutrient most of us no longer get enough of.
Low-risk and cheap, but only if you actually use it, and more is not better. Buying a device? Check the wavelength, the power and the area it covers. A clinic adds assessment, wider coverage and the judgement to combine it with everything else.
Underneath all of it sits the strangest part: why light should heal at all, and how closely the physics lines up with what ancient medicine already said.

“Everything is going to get better. I can feel it.”

My father said that while lying under red light therapy. I almost cried. The words came from somewhere deep in him, and none of us had heard that kind of conviction from him in a long time. He had flown in to see me while his mental health was slipping and his memory had started to go. Red light was one of several things I was using. Months later, he was right.

I know how that sounds. Red light therapy has become a wellness gadget, a mask you wear for better skin. But light has always been medicine. We still shine blue light on jaundiced newborns ¹ and bright light on winter depression ². Read the actual evidence and red light deserves more than a smoother complexion. I think the next era of medicine will use light seriously again, the way older traditions always did.

Here is what the research can measure, what Ayurveda adds, and how I actually use it. The short video above is one small piece of it: why I wear red-tinted glasses at my screen. Below, I widen the lens to the whole body.

What is red light therapy?

Red light therapy is the use of specific wavelengths of light shone onto the body, usually red at 660 and near-infrared at 850 nanometres ³. Some machines use lasers; most now use LEDs. What matters is not the light itself but what it does once it reaches your cells, and how deep it gets ^4–6.

What are the benefits of red light therapy?

Start with skin, because that is where the marketing lives. In controlled trials red light thickens collagen, by around thirty per cent in one ^7–9, and helps hair grow back ^10–12. But skin is the least interesting part.

The same light eases muscle, joint and nerve pain ^13–17, speeds recovery after hard training ^18–20, and calms the mouth ulcers that chemotherapy and radiotherapy cause ^{21, 22}. It shows real signal for cognition ^23–28, for mood ^{29, 30}, and for the ageing retina ^{31, 32}. Earlier work hints at the heart, metabolism and lungs, though most of that is still in animals ^33–38.

One honest line sits over all of it. A 2025 review of 204 randomised trials found genuine but patchy benefit: solid for a handful of uses, thin for the rest, and badly in need of better trials ³⁹. That patchiness stopped bothering me the day I began thinking of light less as a treatment and more as a nutrient most of us no longer get enough of. More on that shortly.

How does red light therapy work?

Three things happen when red light reaches a cell.

It makes energy. The light is absorbed by an enzyme in your mitochondria, the tiny power plants inside every cell, which then produce more ATP, the fuel you run on ^40–42. In a dish of muscle cells, one Harvard group measured ATP doubling or tripling after a single dose ⁴³. In a living body it is gentler, but the idea holds: you are helping the cell recharge its own battery.

It opens the plumbing. Light nudges nitric oxide, which widens small blood vessels and brings more oxygen and nutrients to the tissue ⁴⁴.

And it toughens the cell. A small dose is a mild stress, like exercise, and the cell answers by building up its own repair and defences ^{45, 46}. Which is exactly why more is not better: past a useful dose the benefit fades, and can reverse. It also quietens inflammation, part of why tissue heals faster under it ^{41, 47, 48}.

Red light therapy, sunlight and Ayurveda

Long before anyone measured a wavelength, people treated the sun as medicine. That instinct was not wrong.

At dawn and dusk the sun sits low, its light slanting through so much atmosphere that the blue and ultraviolet scatter away, leaving mostly red and infrared ⁴⁹. That soft red morning light is, quite literally, nature’s own red light therapy, and it is roughly what a panel imitates. Midday is the opposite: full spectrum, full strength, ultraviolet at its peak ⁵⁰. Ayurveda reads that fierce midday light as Pitta, the fire that digests and transforms, and tells you to eat your largest meal under it. Modern chronobiology, watching metabolism rise and fall across the day, lands in a similar place ^{51, 52}.

We evolved inside that rhythm, days outdoors and evenings by firelight. Now we live it backwards: bright blue screens at midnight, dim grey rooms at noon ⁵². My suspicion is that many of us are in essence starved of the right light at the right time. So when red light helps with sleep, energy and mood, we are not adding something strange to the body. We are giving back something we took away; the same indoor life which leaves many of us low in vitamin D ⁵³.

None of this is new. Hippocrates prescribed sunlight and built sun terraces for his patients ⁵⁴. The Charaka Samhita, the founding text of Ayurvedic medicine, sets out measured sun exposure, atapa sevana, as a treatment ⁵⁵. In 1903 a Danish physician won a Nobel Prize for curing a disfiguring skin tuberculosis with focused light ⁵⁶, and sun cures stayed mainstream for tuberculosis until antibiotics replaced them ⁵⁴.

A panel is not the sun, though. It copies one wavelength, not the whole moving spectrum, and none of the rhythm, the intensity or the simple fact of being outdoors. So the question is never just “is red light good?” It is, is this the right dose, at the right time, for this person?

Why should light heal at all?

If you have ever wondered why light should heal anything at all, here is where I land.

We already treat with energy constantly and think nothing of it. Radiotherapy is targeted radiation. Ultraviolet clears psoriasis. Magnetic pulses treat depression. Sound waves shatter kidney stones. Light belongs in that ordinary company, not in some stranger one.

Go deeper and it does get strange. Everything you are made of is atoms, and almost all of an atom’s mass is not solid matter at all. It is energy, held in a stable shape. You are, in a real way, energy wearing a shape ⁵⁷. Structure alone does nothing; what moves it, what turns one thing into another, is light, the electromagnetic field acting on matter ⁵⁸. Ayurveda drew the same picture in older language, calling the solid elements earth and water, and calling light and transformation Tejas, the fire of Pitta ⁵⁹. The physicist John Hagelin later mapped that correspondence formally, placing the particle of light with the fire element ⁶⁰. It is why I think light belongs to the future of medicine as much as its past, at the point where the newest physics and the oldest traditions quietly meet.

Red light therapy at home, or in a clinic?

For a clear, simple goal, a home device is usually enough, and I use one myself. Ignore the marketing and check three things: the wavelength (660 and 850 nanometres are the studied ones), the power actually reaching your skin at the distance you will use it (weak devices look identical and do nothing), and how large an area it covers ⁶¹. Three to five short sessions a week is the usual rhythm.

But honestly, the most important factor is whether you will actually use it. The internet is full of expensive masks worn twice and left in a drawer. A cheap device used for six weeks beats a brilliant one you never switch on. Buy one, commit to it, then judge.

A clinic adds what a device cannot: assessment, stronger and wider coverage, and the judgement to combine light with everything else, or to leave it out.

Is red light therapy safe? Side effects and cautions

For most people it is about as low-risk as medicine gets. No drugs, cheap over time, and side effects that rarely go past some warmth or redness for a day ⁶².

A few people should check first: if you take something that makes your skin light-sensitive, such as certain antibiotics, isotretinoin or St John’s wort ⁶³; if you have photosensitive epilepsy; if you are pregnant; or if the skin is broken or freshly burnt. On the eyes, a red LED at sensible power is generally safe and may even help the ageing retina ³¹, which is why I do not wear goggles, though I will protect a patient’s eyes if there is any doubt ⁶⁴.

Cancer deserves more care. The theoretical worry is that extra cellular energy could feed a tumour. In practice light is used routinely in cancer care, including for chemotherapy mouth ulcers ²¹, and has not been shown to promote tumours ⁶⁵. Still, where there is an undiagnosed lump or a known cancer, I think it is important to weigh it out loud with the person rather than assume.

There is also the older lens. In Chinese medicine red and warmth are Yang in nature: they move Qi and blood and disperse cold and stagnation, and this is much of the logic behind pairing light with acupuncture points. Colour therapy traditions read it the same way, red warming and stimulating, blue cooling and calming ⁶⁶. That same logic sets the caution. In someone already running hot, wired or inflamed, a heat or excess pattern, warming and stimulating them further does not make sense. Ayurveda reaches the same rule in its own language: do not pour more fire on Pitta.

How I use red light therapy with patients

There are studies combining acupuncture points with red light ^67–71, but the combination literature is thin, and no trial is run on the person sitting in front of me. So I work from first principles: what is the mechanism, what does this particular body need, and will adding this earn its place.

I rarely use red light on its own. I reach for it most with people worn down by fatigue, poor sleep, anxiety or low mood, always as one part of a wider plan built for the person.

In a single session I might have three panels running around someone while an IV drips and electroacupuncture works, red light over whatever we most want to move. Other times I leave it out. I often warm the needles or the skin as well. Heat opens the small vessels and brings blood, oxygen and comfort to where we are working, and comfort matters more than we admit in someone who is unwell.

What shifts is not only physical. Give a depleted body more energy to work with, and the mind and the sense of self start finding their way back. You see it in small things: someone mentions they rang an old friend at the weekend, or they laugh mid-sentence for the first time since you met them. I watched the same happen with my own father. Those are the moments I do this work for.

Frequently asked questions

How much does red light therapy cost?

Professional red light therapy as an add-on costs an extra 40 euros where I work, though it may be more or less in other clinics. An at-home device can cost anywhere from 100 euros to over 3,000, depending on its size and power.

Is red light therapy worth it?

It depends on what you are using it for, and I hope this page has helped you judge. It is not the cure-all the internet promises. Matched to a specific goal with honest expectations, it earns its place.

How long and how often? Is ten minutes enough?

With most home devices, sessions last 10 to 20 minutes, three to five times a week. In clinic I vary the timing depending on the goal.

Are there side effects, and what is the real downside?

Side effects are usually mild and temporary: some warmth, redness or irritation, usually gone within a day. The bigger downsides are the cost, the discipline to keep using it, and inflated expectations.

Who should not use it, and where should you avoid it?

Check with your doctor first if you take a medicine that makes you light-sensitive, if you have photosensitive epilepsy, or if you are pregnant. Do not treat over an undiagnosed lump, a new or changing mole, or a known cancer without medical advice, and take care around the eyes at higher power.

Do you really need goggles?

At sensible power a red LED is generally safe for the eyes, and there is even evidence red light can help the ageing retina, which is why I do not always wear them. With higher-power devices, or if there is any doubt, use eye protection.

Can red light therapy cure skin cancer, such as a basal cell carcinoma?

No. Red light therapy is not a cancer treatment, and you should not use it on a suspicious skin lesion. Any new, changing or non-healing patch needs a doctor’s eyes, not a light panel. There is a separate, supervised hospital treatment called photodynamic therapy for some skin cancers, but that is a different thing altogether.

Three honest reasons. Many were never taught about it; the evidence is genuinely uneven; and the wall of hype around it makes careful clinicians wary. As better trials arrive, that is slowly changing.

What is the best time of day to use it?

Morning or daytime fits the body’s own rhythm, the hours when we evolved to take in red and infrared light. I would avoid bright, stimulating sessions late at night, when the body is trying to wind down.

Where can I get red light therapy in Malta?

I use it at Serenity Holistic Medical Clinic in Swieqi, as part of a wider plan rather than on its own. There are other places in Malta that offer it too, so do your own research and find the one that fits you best.

Dr Shehan Wijesingha, MD, M.TCM, DipAP, BMedSci, CPT. Vice President, Association of Ayurvedic Professionals UK.

Medical disclaimer: This page is for educational purposes only. It is not a substitute for individual medical assessment, diagnosis, or treatment. Do not start, change, or stop any treatment, or delay urgent medical care, based on this page alone. If your symptoms are new, severe, or getting worse, contact your GP, go to an emergency department, or call the appropriate Maltese service first.

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