Red light therapy, also called photobiomodulation, shines red and near-infrared light in roughly the 600 to 1000 nm band on the skin at a level that barely warms it. Its best-supported use is clinical: international cancer-care guidelines recommend it to prevent and ease the painful mouth sores that chemotherapy and radiation cause. For skin texture, pattern hair loss, and knee, neck and tendon pain there are modest emerging signals, often from small trials, some run by the companies that sell the devices.
The claims that it burns fat, raises testosterone, or improves general wellness are the weakest in the field, resting on short trials, animal work, or no human trials at all. Whether it works comes down to two things: hitting the right light dose, since the response has a middle window and more is not better, and the quality of the device.
Findings & Outcomes
What It Is
Red light therapy, called photobiomodulation in the research and formerly low-level laser therapy, is the use of red and near-infrared light in roughly the 600 to 1000 nm band, applied to the skin at a level that warms the tissue very little. The longer near-infrared wavelengths reach deeper than the red ones. It is available two ways: as a clinic treatment, and as a fast-growing market of home panels, masks, wands and caps. The effect, where there is one, is attributed to specific wavelengths being absorbed inside the cell.
What It Does
Red light has a short list of supported uses, and they sit at very different strengths. The strongest evidence is clinical. International cancer-care guidelines recommend photobiomodulation to prevent and reduce oral mucositis, the painful mouth and throat ulceration that chemotherapy and radiation cause, in defined treatment settings. This is delivered inside cancer care by trained staff, not at home.
Closer to everyday use, several applications carry a modest emerging signal. Skin texture and fine lines, pattern hair loss, and knee, neck and tendon pain each have controlled or pooled trial evidence for a small benefit. Most of these trials are small and short, and many were funded or run by the companies that sell the devices, which tends to inflate the apparent effect. Expect a gradual change built over weeks.
The weakest claims are fat loss and body contouring, where short and often industry-linked trials have measured a smaller waist without any lasting fat change, and testosterone or hormone claims, which rest on animal and mechanistic work with no human trials. Sort these three groups apart before buying a device. The graded research below places each use at the strength its own evidence supports.
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
Cancer Risk And Outcome
Guidelines recommend it to prevent the mouth sores of chemo and radiotherapy
For people going through chemotherapy or radiation, shining specific red and near-infrared light into the mouth lowers the chance and the severity of the painful mouth sores those treatments cause. It works well enough that international cancer-care guidelines recommend it in particular situations, which makes it the strongest use red light has.
Oral mucositis is one of the more debilitating side effects of cancer treatment, and photobiomodulation applied to the oral tissues before or during treatment reduces how severe it gets and how much it hurts. The evidence was strong enough that the Multinational Association of Supportive Care in Cancer and the International Society of Oral Oncology built it into their mucositis guidelines: recommended to prevent oral mucositis in adults undergoing hematopoietic stem-cell transplantation with high-dose conditioning chemotherapy, in patients having radiotherapy without chemotherapy for head and neck cancer, and in patients having radiotherapy with concurrent chemotherapy for head and neck cancer. A 2026 randomized, double-blind, sham-controlled trial of an intraoral photobiomodulation device in head and neck radiotherapy provides direct trial confirmation. The main open questions are the exact wavelength, dose and treatment schedule, which vary between studies and clinics.
Who this may not transfer to:Studied in adults having stem-cell transplant or head and neck radiotherapy; this is a clinical treatment delivered by trained staff, not a home use.
This is a treatment delivered inside a cancer-care setting by trained staff, not a home practice. If you or someone you care for is starting chemotherapy or head and neck radiotherapy, it is reasonable to ask the oncology team whether photobiomodulation for mucositis is available where you are treated.
The studies · 2
Zadik et al., systematic review of photobiomodulation for the management of oral mucositis in cancer patients and clinical practice guidelines · Supportive Care in Cancer 2019;27(10):3969-3983
Randomized, double-blind, sham-controlled trial of an intraoral photobiomodulation device for oral mucositis due to radiotherapy for head and neck cancer · Supportive Care in Cancer 2026
Skin And Hair
Laser caps raise hair density versus a sham device in pattern hair loss
For pattern hair loss, wearable red-light caps and combs increase how much hair grows back compared with a fake device in the trials that have tested them. Several small studies point the same way, so the signal is consistent. The catch is that the trials are small, short, and often run by the companies selling the devices, so treat the effect as modest and not yet pinned down.
Low-level laser therapy for androgenetic alopecia has been tested in a number of randomized, sham-controlled trials, and a meta-analysis pooling them found a statistically significant increase in hair density with active treatment over sham. It is the best-supported of red light's appearance-related uses. The limitations are substantial: most trials ran for a few months, samples were small, follow-up was short, and a large share of the studies had manufacturer involvement, which tends to inflate apparent effects. It has not been compared head to head over the long term against the established treatments, topical minoxidil and, in men, oral finasteride.
Who this may not transfer to:Trials in adult men and women with pattern hair loss; effect sizes are small and many studies had device-maker involvement.
If you are considering a home red-light device for pattern hair loss, treat it as an add-on with a modest, still-uncertain payoff rather than a replacement for the treatments with the deepest evidence. Our hair loss guide covers what minoxidil and finasteride actually do.
The study · 1
Liu et al., comparative effectiveness of low-level laser therapy for adult androgenic alopecia: a systematic review and meta-analysis of randomized controlled trials · Lasers in Medical Science 2019;34(6):1063-1069
About 30 sessions smoothed fine lines and raised measured collagen density
People who did a run of red and near-infrared light sessions ended up with smoother skin, fewer fine lines, and more measured collagen under the surface than when they started. The collagen rise was measured on ultrasound, not only self-reported. The study was small and did not include a fake-light group, so part of the change could be down to expectation, and this is early rather than settled science.
In a prospective controlled trial, participants were treated with red or near-infrared light over roughly 30 sessions. Blinded evaluation of photographs and ultrasound assessment of dermal collagen showed improved skin complexion and self-reported skin feeling, reduction in fine lines, wrinkles and skin roughness, and an increase in intradermal collagen density. The two active light sources performed similarly. The design's main weakness is the absence of a blinded sham-light arm: the comparison was against an untreated, unmasked control group rather than a placebo light, so part of the improvement could reflect expectation, and the sample was modest. This trial also had device-maker involvement, and skin trials in this field are frequently industry-linked.
Who this may not transfer to:One controlled trial in adults; the smoothing likely generalizes across skin types but has not been confirmed against a sham-light group.
Red-light devices for skin can produce a modest improvement in texture and fine lines with consistent use over weeks. Set expectations at gradual smoothing rather than a dramatic change, and judge results over a couple of months rather than a few sessions.
The study · 1
Wunsch & Matuschka, a controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase · Photomedicine and Laser Surgery 2014;32(2):93-100
Added light may aid healing of chronic lower-leg wounds, on very low-certainty evidence
For stubborn wounds on the lower legs, adding red and near-infrared light may help them heal, especially diabetic foot ulcers, in the small trials that tested it, but the evidence is very low certainty. Lower light doses did better, and the one study using a very high dose did nothing, which fits the sweet-spot pattern where more light is not better. These were small studies with very different settings, so it is an encouraging early signal rather than a reason to make it routine yet.
Chronic lower-limb wounds, including venous and diabetic ulcers, heal slowly and are difficult to treat, so any additional lever is of interest. A systematic review of six randomized trials of LED photobiomodulation for these wounds concluded it may reduce wound area, improve the wound bed and increase local microcirculation, particularly in diabetic foot ulcers, but rated the overall certainty of the evidence very low. The benefit was concentrated at lower energy densities; the one trial using a very high dose (126 J/cm2) did not help and was associated with a longer healing time, in keeping with the biphasic dose window. The evidence base is limited by small samples, wide variation in wavelength, irradiance and total dose, and by an inability to pool the trials, which also leaves the ideal protocol unclear. It is applied clinically as an adjunct to standard wound care rather than a replacement for it.
Who this may not transfer to:Belongs in a clinical wound-care setting alongside standard treatment, not self-directed use of a consumer panel on a serious wound.
Wound photobiomodulation belongs in a clinical wound-care setting alongside standard treatment, not as a self-directed use of a consumer panel on a serious wound. Anyone with a non-healing wound should have it assessed rather than treated at home.
The study · 1
Clinical dosimetry and efficacy of LED photobiomodulation for chronic lower-limb wound healing: a systematic review of randomized trials · Lasers in Medical Science 2026
Pain
Cuts knee arthritis pain about 15 mm on a 100 mm scale, only at an adequate dose
For knee arthritis pain, red and near-infrared light beat a fake treatment, cutting pain by roughly 15 points on a 100-point scale by the end of a course, but only in the studies that used enough light. When the dose was too low, it did about nothing. So the light can help the knee, and the dose is what separates the studies that worked from the ones that did not.
A systematic review and meta-analysis of randomized placebo-controlled trials examined low-level laser therapy for knee osteoarthritis pain and disability. Pooled across the trials, active treatment reduced pain compared with placebo, on the order of 15 mm on a 100 mm visual analog scale at the end of the treatment course, with relief persisting for some weeks afterward. The effect was strongly dose-dependent: trials delivering an adequate dose showed clear benefit, while under-dosed trials showed little to none, which explains much of the mixed reputation of the therapy for joint pain. Heterogeneity between protocols remains the main limitation.
Who this may not transfer to:Adults with knee osteoarthritis; the benefit depends on an adequate light dose and works best alongside exercise.
For knee osteoarthritis, red-light and low-level laser treatment can take the edge off pain when an adequate dose is used, so try it as one part of a plan that also includes the most effective measure, exercise and strengthening around the joint. Judge it over a full treatment course, not a session or two.
The study · 1
Stausholm et al., efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials · BMJ Open 2019;9(10):e031142
Eases neck pain, with relief lasting up to 22 weeks after the sessions stop in chronic cases
For neck pain, red and near-infrared light beat a fake treatment, and in longer-standing neck pain the relief kept going for up to 22 weeks after the sessions stopped. The studies were mostly short with different setups, so it is a fair option to try rather than the first thing to reach for.
A systematic review and meta-analysis published in a major medical journal pooled randomized placebo and active-treatment controlled trials of low-level laser therapy for neck pain. Active treatment produced greater pain relief than placebo, and in chronic neck pain the benefit was maintained for up to 22 weeks after the end of a treatment course, which is longer than many passive treatments manage. As with other pain uses, the trials were mostly short, and wavelength and dose differed between them, so the durability beyond that point and the best protocol are less certain.
Who this may not transfer to:Adults with acute and chronic neck pain; most trials were short, so durability beyond a few months is less certain.
Red-light or low-level laser treatment is a reasonable option to try for neck pain, especially longer-standing pain, alongside movement and the exercises that address the underlying cause. Expect relief that builds over a course of sessions rather than an instant fix.
The study · 1
Chow et al., efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials · Lancet 2009;374(9705):1897-1908
Lowers tendon pain and improves function, but only at the right wavelength and dose
For tendon pain, red and near-infrared light can lower pain and improve how the tendon works, but only when the wavelength and dose are in the right range. Studies that used the wrong settings found little, which is why the overall picture looks mixed. Getting the parameters right accounts for most of the difference.
A systematic review with meta-analysis assessed low-level laser therapy across tendinopathies. The pooled picture was mixed, but a consistent finding was that outcomes depended strongly on treatment parameters: trials using wavelengths and doses within a recommended window tended to show reduced pain and improved function, while trials outside that window tended to show little effect. This parameter sensitivity is the likely reason the therapy has an uneven reputation for tendon problems. Sample sizes were generally small and the tendons studied varied, so the strength of benefit for any one tendinopathy is uncertain.
Who this may not transfer to:Adults with various tendinopathies; results hinge on the correct wavelength and dose, and it works as an adjunct to loading exercise.
For a troublesome tendon, red-light or low-level laser treatment is worth trying as an adjunct to loading exercise, which is the mainstay for tendinopathy, provided the device and settings fall in the effective range. Track your own response over a course rather than expecting a quick change.
The study · 1
Tumilty et al., low level laser treatment of tendinopathy: a systematic review with meta-analysis · Photomedicine and Laser Surgery 2010;28(1):3-16
Exercise Recovery
Light before a workout adds a small gain in reps and time to exhaustion
Shining red and near-infrared light on the muscles before a workout let people do a bit more, more reps or longer to exhaustion, and left them with lower signs of muscle strain afterward. The gains were small to moderate, timing before exercise mattered, and a lot of the research traces to one lab, so it needs confirming more broadly.
A systematic review with meta-analysis pooled trials of phototherapy applied to muscle before exercise. Active treatment improved exercise performance measures (such as repetitions and time to exhaustion) and lowered post-exercise markers of fatigue and muscle damage, including creatine kinase, relative to placebo. Effect sizes were small to moderate. The results depend on the light being applied before, not after, exercise, and on wavelength and dose. A notable caveat is that a large fraction of the trials originate from a single research group, so independent replication across labs is what would move this from emerging toward established.
Who this may not transfer to:Mostly young, active adults, and much of the trial base comes from one research group, so wider replication is still needed.
If you want to experiment with red light for training, the evidence points to using it on the muscles before a session rather than after, for a modest edge in output and recovery. Keep expectations proportionate: this is a small effect on top of training, not a substitute for it.
The study · 1
Leal-Junior et al., effect of phototherapy (low-level laser therapy and light-emitting diode therapy) on exercise performance and markers of exercise recovery: a systematic review with meta-analysis · Lasers in Medical Science 2015;30(2):925-939
Weight And Fat Loss
A few centimeters off the waist in short trials, with no lasting fat loss shown
Studies of red-light body-contouring devices have measured small drops in waistline, a few centimeters, over short trials. A smaller waist measurement is not the same as losing fat or keeping weight off, the studies were brief and often run by device makers, and none show a lasting change. So the fat-burning claim is far bigger than the evidence supporting it.
A systematic review of low-level laser therapy for reducing body circumferences pooled short trials, mostly in the abdomen, hips and thighs. It found modest reductions in measured circumference, typically a few centimeters, over treatment courses of a few weeks. The important limits: circumference is a tape-measure reading, not a measurement of fat mass, and can shift for reasons unrelated to fat; the trials were short with no long-term follow-up; and this is a commercially active area where many studies have manufacturer involvement. There is no good evidence that these devices produce durable fat loss or weight change, which is the claim marketing tends to imply.
Who this may not transfer to:Short trials, largely in women; a smaller waist measurement is not the same as lost fat and no durable change has been shown.
Treat red-light fat-loss and body-contouring claims as the weakest part of the field. If a smaller waistline measurement over a few weeks is what you are after, the effect is small and may not last; for lasting change, the approaches with evidence are diet, activity and strength training.
The study · 1
Low-level laser therapy for reducing body circumferences: a systematic review · Lasers in Medical Science 2025
How it works
Light is absorbed by cytochrome c oxidase in the mitochondria, nudging up cell energy
The way red light is thought to work: certain red and near-infrared wavelengths are absorbed by an enzyme in the mitochondria, the cell's energy-producing structures, nudging up energy output and switching on repair and anti-inflammatory signals. It is a well-studied and believable explanation, mostly from lab work, and it tells you why the exact color of light matters. A good mechanism is a reason to study something, not a guarantee it helps.
Photobiomodulation is proposed to work through the absorption of red and near-infrared photons by chromophores in the cell, chiefly cytochrome c oxidase, complex IV of the mitochondrial electron transport chain. The absorbed light is thought to transiently raise mitochondrial membrane potential and ATP production and to modulate reactive oxygen species and nitric oxide, triggering downstream signaling that affects inflammation, blood flow and tissue repair. This account, developed largely from in-vitro and animal studies, explains why efficacy is wavelength-specific: the target chromophore absorbs in defined bands. It remains the working model rather than a fully proven pathway, and the step from this cellular mechanism to a measured clinical effect is exactly what the trial evidence, claim by claim, has to establish.
Who this may not transfer to:Cell and laboratory models; this is a proposed mechanism, not a clinical outcome, and each use has to earn its benefit in trials.
The study · 1
de Freitas & Hamblin, proposed mechanisms of photobiomodulation or low-level light therapy · IEEE Journal of Selected Topics in Quantum Electronics 2016;22(3):7000417
A biphasic dose response: a mid-range dose works and too much cancels it
With red light there is a sweet spot. Too little and nothing happens; the right middle dose does the work; too much can undo it. Because of this, the settings, the color of light, how bright it is, how far away you sit and for how long, matter more than how powerful the device sounds, and turning it up higher does not help.
A central and repeatedly observed feature of photobiomodulation is a biphasic, or bell-shaped, dose response, sometimes described by the Arndt-Schulz rule. Below a threshold dose there is no effect; within an effective window there is a beneficial response; above it the response diminishes and can reverse, becoming inhibitory. This has been documented across cell and animal studies and is a leading explanation for why trials with poorly chosen parameters fail while well-dosed trials succeed. The practical consequence is that the outcome depends on the combination of wavelength, irradiance (power per area), distance and exposure time, not on how strong a device sounds; more is not better, and past the window it can be worse.
Who this may not transfer to:Cell and animal dose-response studies; the exact dose window varies by tissue, so the reliable point is that more is not better.
The study · 1
Huang et al., biphasic dose response in low level light therapy · Dose-Response 2009;7(4):358-383
How It Works
Anatomy of the Practice
1What reaches the tissue
Red and near-infrared light passes through the outer skin and is absorbed a few millimeters down, and the longer near-infrared wavelengths reach deeper than the red ones. The power is low, so the tissue is barely warmed, and the proposed effect is attributed to the absorbed photons themselves.
2Inside the cell
The leading account is that the light is absorbed by cytochrome c oxidase, an enzyme in the mitochondria, briefly raising energy production and shifting signaling molecules that affect inflammation, blood flow and repair. This is drawn mostly from laboratory and animal work, and it is why the exact wavelength matters.
3Over a course of sessions
Where there is a clinical effect, on mouth sores in cancer care and on some skin, hair and pain measures, it builds over weeks of regular sessions and depends on delivering an effective dose each time. Below the effective window nothing happens, and above it the response falls off.
Choosing and Using a Device
Whether red light does anything comes down to two things: the dose of light that reaches the tissue, and the quality of the device delivering it. The dose is set by four numbers:
- the wavelength
- the irradiance (power per area, often given in mW/cm2)
- the distance from the skin
- the session time
The response has a middle window, so the aim is the middle of it; turning the power up or sitting longer does not add benefit and past the window can reduce it.
Device quality is the harder problem. The home market ranges from well-measured units to panels and masks that emit far less usable light than their marketing claims. A clinic can deliver a controlled, higher-powered dose for a specific problem, which is where the mucositis and wound-care work is done. A home device can be reasonable for skin or mild pain if it publishes its optical output, ideally with third-party measurement.
A seller who cannot give you the wavelength, the power per area at a stated distance, and a session time cannot tell you the dose you are getting.
Ways to Do It
Match the use to the evidence, check the four dose numbers, decide between a clinic and a home device, and give it a fair course. Set expectations at a modest change for the emerging uses.
The strongest use is clinical: oral mucositis in cancer care. The next best are skin, hair, and certain knee, neck or tendon pain, all modest. If you are buying a home device, buy it for one of those, and treat the fat-loss and general-wellness pitches as the weak end.
An effective device states a wavelength in roughly the 600 to 1000 nm range, an irradiance (power per area, often in mW/cm2) at a stated distance, and a session time. Aim for the middle of the dose window, not the maximum, since more power and longer sessions can do less.
A clinic delivers a controlled, higher-powered dose for a specific problem, and is where the mucositis and wound-care work is done. Home panels and masks trade power and precision for cost and convenience, and their quality varies widely. For a home unit, favor ones that publish their optical output and, where possible, third-party measurement.
Where red light works, it works over weeks of regular sessions, so judge skin or pain over a couple of months of use. Expect a modest, gradual change for the emerging uses, and be ready to conclude it did little for you, since the effect sizes are small and personal response varies.
Go Deeper
- Mitochondria: the structures that hold cytochrome c oxidase, the proposed target of the light, and the reason the mechanism is framed around wavelength.
- Hair loss: what helps pattern hair loss, where low-level laser fits, and how it compares with minoxidil and finasteride.
- Arthritis: the fuller picture for joint pain, including where light and low-level laser sit alongside exercise, the most effective measure.
- Neck and shoulder pain: the everyday pain where low-level laser has some of its better evidence, set among the rest of what helps.
The Chinese Medicine View
Red light therapy is a modern practice built on cell biology, and the classical Chinese texts describe nothing like a light panel. What the tradition does hold is that warmth and light are Yang in nature, and that Yang warms and moves the body. A modern reader can loosely place a warming, activating light therapy near the idea of supporting Yang and moving Qi and Blood in a local area. That is an orientation, not a claim that the tradition anticipated photobiomodulation. Qi is not a wavelength, and Yang is not mitochondrial energy.
The same lens raises a caution. Chinese medicine would not treat such a therapy as equally suited to everyone. In a pattern of empty heat, the night sweats, dry mouth and restlessness of Yin deficiency, a tradition-minded practitioner would be more careful with anything framed as adding warmth or activity, and would weigh constitution, current state and the specific complaint before applying one input to all. What Chinese medicine offers here is a way of thinking about who a warming, local therapy suits, not an account of how the light works.
Cautions For This Practice
Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
Protect your eyes from direct exposure
Bright red and especially near-infrared light can reach the retina, and near-infrared is invisible, so the eye does not blink or look away as it would from visible brightness. Use eye protection, closed eyes, or the goggles a device supplies whenever a panel is near the face, and avoid looking directly into a strong source. This is the main handling caution for an otherwise low-risk practice.
Be careful with photosensitizing medicines and conditions
Some medicines and supplements raise sensitivity to light, including certain antibiotics, retinoids, St John wort and some diuretics, and some skin conditions flare with light. If you take a medicine that carries a sun-sensitivity warning or have a light-sensitive condition, check with a pharmacist or doctor before regular light sessions.
Get a suspicious skin lesion checked, not lit
A new, changing, or unusual mole or skin lesion needs assessment by a clinician, not a course of light. Do not use a device over an undiagnosed lesion or a known skin cancer; have it looked at first.
Device quality and dose are uncertain
Home devices vary widely in the light they actually emit, and because the effect depends on hitting a dose window, an underpowered or vaguely specified device may deliver too little to do anything. The main downside with red light is financial: money spent on a device or a claim the evidence does not support. Favor devices that publish their wavelength and output, and treat sweeping wellness promises with care.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
Common Questions
Does red light therapy actually work, or is it hype?
Both, depending on the use. Its best-evidenced use is clinical: cancer-care guidelines recommend photobiomodulation to prevent and reduce oral mucositis, the painful mouth sores from chemotherapy and radiation. The everyday uses are more modest. A controlled skin trial found smoother fine lines and more measured collagen after a course of about 30 sessions; pooled trials cut knee osteoarthritis pain by roughly 15 mm on a 100 mm scale when an adequate dose was used; and pattern hair loss, neck pain and tendon pain show small benefits, often in trials run by device makers. The fat-loss, testosterone and general-wellness claims are the weakest in the field.
What wavelength and dose should a device have?
Effective devices work in the red to near-infrared range, roughly 600 to 1000 nm, and state their irradiance (power per area, often in mW/cm2) at a set distance along with a session time. The response has a middle window, so aim for a mid-range dose; more power and longer sessions are not automatically better and can be worse. A device that will not state its wavelength and output at a set distance is not telling you the dose, and without the dose you cannot tell whether it can do anything.
Can red light therapy burn fat or raise testosterone?
These are the weakest claims in the field. Short body-contouring trials have measured a smaller waist or hip circumference, but circumference is a tape-measure reading, not a measure of fat mass; the studies were brief and often industry-linked; and none show lasting fat or weight change. Testosterone and hormone claims rest on animal and mechanistic work with no human trials. For lasting change in body composition, the approaches with evidence are diet, activity and strength training.
Is a home panel as good as a clinic treatment?
Not usually. A clinic can deliver a controlled, higher-powered, targeted dose, and that is where the wound-care and mucositis work is done. Home panels and masks trade power and precision for cost and convenience, and their quality ranges from well-measured units to devices that emit far less usable light than claimed. A home device can be reasonable for skin or mild pain if it publishes its optical output and you use it consistently, but keep expectations modest: the effect for the emerging uses is small and builds over weeks.
Is it safe?
For most people it is low-risk, and reported side effects in trials tend to be mild and temporary, such as brief warmth or redness. The main handling caution is the eyes: bright red and invisible near-infrared light can reach the retina, so use the eye protection a device supplies and avoid staring into a strong source. Take extra care if you use photosensitizing medicines or have a light-sensitive skin condition, and have any suspicious skin lesion assessed by a clinician before using a device on it. The fuller list is in the cautions section above.
Explore Related
Other pages this one connects to, by the evidence they share, the outcomes they touch, and the ground they cover.
How this connects
- How it works
All 12 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 9, 2026.
Evidence strength
How confidently the research supports a claim. Strength describes the evidence, not our endorsement.