What is red light therapy, and what does the evidence support?

Red light therapy uses devices such as LED masks, caps, panels and low-power lasers that shine red or near-infrared light onto the body. How red and near-infrared light acts on cells is still under study. In sham-controlled trials, home-use laser hair devices increased hair density in adults with pattern hair loss over up to about six months. Red light therapy devices sold for medical uses are FDA-regulated medical devices; clearance covers specific products and uses, not every use offered.

Overview

The best evidence for an at-home device is for pattern hair loss: in sham-controlled trials, home-use laser combs, caps and helmets increased hair density in adults over up to about six months.[1][2] Evidence that home-use laser devices increase hair density in adults with pattern hair loss comes from randomized, sham-controlled trials and from independent reviews of those trials.[1][2][3]

Mechanism

Researchers are studying how red and near-infrared light affect cells. Cell and short-term measurement studies do not show health benefits.

Why People Use It

Red light therapy devices sold for medical uses are FDA-regulated medical devices; clearance covers specific products and uses, not every use offered.

Red light therapy is offered for several different purposes, from cosmetic skin care to pain and hair loss, and the strength of the evidence differs by use.

Evidence

Red light therapy devices sold for medical uses are FDA-regulated medical devices; clearance covers specific products and uses, not every use offered.

Evidence levels on this page follow our grading key: Established means consistent results from randomized trials or a systematic review of them; Emerging means some controlled human evidence that falls short of that, for example small trials or trials funded mostly by a device's maker; and "No trial found" means our searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026 found none. In these tables, Not published means that in searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026 we found no published data for that cell. Each row names the device type that was studied, and a result for one device type does not carry over to another. Results from one type of device, such as a clinic laser, do not automatically apply to another, such as an at-home LED mask.

Pain: clinic laser studies

Some reviews of clinic laser treatment found short-term pain relief for neck pain, low back pain and knee osteoarthritis at specific doses, but results conflict and many trials were small. A 2019 review of 22 placebo-controlled trials in 1,063 people with knee osteoarthritis (Stausholm 2019) found that clinic laser therapy reduced pain by 14.23 mm more than placebo on a visual pain scale at the end of therapy, and by 18.71 mm at recommended doses: 785 to 860 nanometers at 4 to 8 joules per spot, or 904 nanometers at 1 to 3 joules per spot.[4] The Stausholm 2019 review used dose recommendations from the World Association for Laser Therapy, and its authors include past presidents of that association.[4] An earlier 2015 review of 9 trials with 518 people (Huang 2015) found no significant difference in knee osteoarthritis pain between laser therapy and placebo, including in trials that used recommended doses.[5]

A 2009 review of 16 trials with 820 people with neck pain (Chow 2009) found that clinic laser therapy reduced chronic neck pain by about 20 mm more than placebo on a visual pain scale, with mild side effects that did not differ from placebo.[6] A 2016 review of 15 trials with 1,039 people with chronic low back pain (Glazov 2016) found short-term pain relief compared with sham only in some groups of trials, such as those using at least 3 joules per point, and rated that evidence as moderate quality.[7] Pain relief from clinic laser therapy is rated Emerging on this page: the reviews disagree, results depend on dose, and many trials were small.

In a 50-person sham-controlled study of the MR5 Activ Pro, a clinic device combining a 905 nanometer laser with 850 and 660 nanometer LEDs, run by its maker Multi Radiance Medical, adults with tennis elbow pain had 6 sessions over 3 weeks and the study met its goal of at least 30% pain reduction, but the public summary reports no figures.[8]

Waist and hip measurements

In a 2009 sham-controlled trial of 67 adults aged 18 to 65 with a BMI of 25 to 30 (Jackson 2009), a 635 nanometer clinic laser used three times a week for 2 weeks reduced total waist, hip and thigh circumference by 3.51 inches, compared with 0.68 inches with a sham treatment.[9] In a 2017 sham-controlled trial of adults with a BMI of 30 to 40 (Roche 2017), 30-minute clinic laser sessions three times a week for 4 weeks reduced combined hip, waist and upper-abdomen measurements by 10.52 cm on average, compared with 1.80 cm with a sham treatment; the trial's ClinicalTrials.gov record describes the laser as green light at 532 nanometers, not red light.[10][11] Both circumference trials came from the same research group; the 2017 trial is registered on ClinicalTrials.gov with Erchonia Corporation, the laser's maker, as its sponsor, and the abstract we read for the 2009 trial does not report its funding; a smaller body measurement is not the same as weight loss or fat loss.[9][10][11] The circumference results come from clinic lasers, not from at-home red light devices.

Exercise performance and recovery

A 2022 review of 37 studies in 586 healthy young adults (Dutra 2022) found that red or near-infrared light applied before exercise produced small improvements in muscle endurance in single-joint exercises and in time to exhaustion in cycling, but no effect on strength, sprinting, running time trials or swimming.[12] A 2018 review of 39 trials in 861 healthy people (Vanin 2018) rated the evidence on muscle performance and fatigue as very low to moderate quality, with positive results mostly at 655 to 950 nanometers and 20 to 60 joules for small muscle groups or 60 to 300 joules for large ones.[13] A 2022 review of 24 studies in athletes (Luo 2022) found better lower-limb strength at follow-up, less muscle soreness and lower creatine kinase, a blood marker of muscle damage, after laser therapy, though its authors wrote that a definite therapeutic effect is yet to be established.[14]

One research group active in these exercise trials reports research support from Multi Radiance Medical, a laser maker, and we did not check the funding of each trial in these reviews.[15] In searches of Europe PMC and PubMed for reviews on October 1, 2026, we found one systematic review of whole-body red light beds for exercise (Álvarez-Martínez 2025), covering five small studies, and none of the five reported a benefit on exercise performance or fatigue markers.[16] Evidence on exercise performance and recovery is rated Emerging for light applied to muscles: results vary by type of exercise, and the trials are small.

Skin, Wrinkles and Collagen

In a controlled trial of 136 adult volunteers (Wunsch 2014), twice-weekly sessions in large whole-body light units using red light (611 to 650 nanometers, about 9 joules per square centimeter) or a broader 570 to 850 nanometer spectrum, for 30 sessions, improved skin roughness, collagen density on ultrasound and blinded ratings of photographs compared with an untreated control group.[17] The Wunsch 2014 trial had no sham light, because its authors wrote that a sham light source without any effect most likely does not exist, and it was fully funded by JK-Holding, a maker of the light units.[17]

In one sham-controlled trial of a home-use LED neck device (Park SO 2025) in 70 adults in Korea, 60 of them women, sessions of red and near-infrared light (630 and 850 nanometers) for 9 minutes a day, 5 times a week for 12 weeks led to improved neck-wrinkle scores in 27 of 35 people, compared with 3 of 35 with a sham device, as rated by investigators; the participants' own ratings of overall improvement did not differ between groups.[18] The neck-device trial was a single study, supported by Y&J BIO, the device's maker.[18]

We read three sham-controlled trials of LED masks worn on the face for wrinkles, found in searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026; they tested 4 to 12 weeks of use, and two of the three were funded or sponsored by companies.[19][20][21] In one sham-controlled trial of a home-use LED mask (Park SH 2025) in 60 adults of Asian descent aged 30 to 65, 56 of them women, red and near-infrared light (630 and 850 nanometers) applied to the face for 9 minutes, 5 times a week for 12 weeks led to improvement in wrinkles around the eyes (crow's feet) in 25 of 29 people, compared with 5 of 30 with a sham device, as rated by an independent evaluator; the participants' own ratings of overall improvement did not differ between groups.[19] The crow's feet trial was a single study funded by Y&J Bio, the device's maker; its sham device still gave off red light at one tenth of the intensity, and 4 of the 60 participants reported adverse events, none of them serious.[19]

A sham-controlled study sponsored by Johnson & Johnson Consumer Inc. (ClinicalTrials.gov NCT03312543) enrolled 124 women aged 35 to 70 to use an LED light therapy mask or a sham mask for 10 minutes each evening for 12 weeks; expert graders' averaged ratings of overall wrinkling favored the mask by 0.14 points on a 9-point scale (95% CI 0.02 to 0.25), and one of the three graders' own ratings showed a significant difference.[20] The results of that study are posted on ClinicalTrials.gov; the record describes the mask as LED-based without stating the wavelength or color of its light, and a Europe PMC search for the registration number on October 1, 2026 found no journal article reporting it.[20]

In a sham-controlled trial in 95 women aged 45 to 60 (Bragato 2025), a red LED mask (660 nanometers) used for 21 minutes two or three times a week for 4 weeks did not change specialists' wrinkle-scale ratings of photographs compared with sham; software measurements found shorter wrinkles between the eyebrows and beside the right eye, out of four areas measured, and participants were more satisfied than those in the sham group.[21] We read only the abstract of the Bragato 2025 trial, which does not say whether the mask was used at home or in a clinic; its Europe PMC record lists grants from two research agencies in Brazil and none from a company.[21]

A 2018 systematic review of LED trials in dermatology (Jagdeo 2018) gave skin rejuvenation a grade C recommendation, citing small samples, lack of blinding, no sham controls and varied treatment settings.[22] In a split-face study of 76 people with facial wrinkles (Lee 2007), twice-weekly in-office LED sessions at 830 nanometers, 633 nanometers or both for 4 weeks were followed by up to 36% less wrinkling, but the abstract reports that change against the start of the study, not against the comparison side.[23] Evidence for wrinkles and skin texture is rated Emerging: the trials are small, short or unblinded, expert and participant ratings often disagree, and most were funded or sponsored by companies.

Some light studies measured more collagen in the skin, by ultrasound compared with an untreated group (Wunsch 2014) or in skin samples (Lee 2007), but a collagen measurement does not by itself show younger-looking skin or better health.[17][23] Studies of red light and skin measured wrinkles and skin texture, not aging of the body.

Limitations

Evidence for wrinkles and pain is limited or mixed, and in searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026, we found no clinical trial in people showing that red light therapy slows aging or extends lifespan. Two reviews of the hair trials were not funded by device makers: Liu 2019 was funded by Taiwan's Ministry of Science and Technology, and Lueangarun 2021 reported no funding, and both found more hair density than with sham devices.[1][2] Searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026 found no randomized trial of red or near-infrared light in people that measured biological age, epigenetic age or telomere length, and none designed to test whether it extends lifespan. In a 2025 review of 38 studies (Perez 2025), 2,930 of 3,098 patients had pattern hair loss, and the authors wrote that more studies are needed for other types of hair loss.[24]

Risks and Side Effects

In trials of red light devices, reported side effects were mostly mild and local, such as dryness, redness, stinging, itching, scalp tenderness or a warm feeling.[2][3][22] Most of these trials were short and reported side effects inconsistently. No serious adverse events were reported in any person using the laser comb in the four Jimenez 2014 trials.[3] A 2023 review of clinical and laboratory studies (Glass 2023) found no clinical trial data linking light therapy for skin rejuvenation with new or returning cancer, while animal tumor studies gave varied results with no clear pattern.[25]

A 2024 laboratory study (Ostrin 2024) of two red-laser devices built for myopia treatment in children, which users look into directly, found that 3 minutes of continuous viewing approached or exceeded the maximum permissible exposure, putting the retina at risk of photochemical and thermal damage.[26] Those myopia devices shine light into the eye by design, unlike face masks or skin panels, but an eye injury has been reported with a face mask: a 2020 case report (Kim 2020) described retinal damage in a 37-year-old woman who had used an LED face mask with blue, red and infrared light sources for 20 minutes every other day for about a month, with her eyes open and the eye area uncovered, and its authors attributed the damage to the blue light.[27] A second case report (Labkovich 2026) described a 43-year-old otherwise healthy woman with sudden angle-closure glaucoma in both eyes, secondary to ciliochoroidal effusions, after two weeks of using a red-light therapy mask; her vision returned to 20/20 and the effusions resolved after the mask was stopped and she was treated with medicines that lower eye pressure and with steroids.[28] The authors of that report wrote that choroidal effusions had not been previously described with at-home red-light mask use; we read only its abstract.[28] Case reports each describe one person and cannot show how often this happens, and in searches of Europe PMC and PubMed on October 1, 2026 we found no controlled study of eye injury from LED face masks. The authors of the 2020 case report advised keeping the eyes covered during LED face mask use.[27] Do not look directly into the light, and follow the device's eye-protection instructions. According to the Ostrin 2024 study, both myopia devices it tested were confirmed to be Class 1 laser products.[26]

In draft guidance for device manufacturers (Photobiomodulation (PBM) Devices - Premarket Notification [510(k)] Submissions, issued January 12, 2023, not final), FDA states that 'PBM devices pose a risk for ocular tissue damage as they may deliver energy and irradiance values greater than the maximum permissible exposure for the patient's or user's eyes.' FDA guidance document

In draft guidance for device manufacturers (Photobiomodulation (PBM) Devices - Premarket Notification [510(k)] Submissions, issued January 12, 2023, not final), FDA states that 'it is possible for some PBM devices with relatively higher irradiances or devices that cover certain parts of the body (e.g., masks and helmets) to increase the tissue temperature to dangerous levels if used for long periods of time and/or in close contact.'

If you have severe symptoms, call 911 or seek emergency care. Report side effects to FDA MedWatch.

Contraindication Considerations

Some situations call for checking with a clinician before using a light device.

The prescribing information for Photofrin (porfimer sodium), a photodynamic therapy drug activated by 630 nm red laser light, says all patients who receive it will be photosensitive and must avoid exposing their skin and eyes to direct sunlight or bright indoor light for at least 30 days.[29] The Photofrin label adds that some patients may remain sensitive to light for 90 days or more.[29] Anyone who has recently received a light-sensitizing photodynamic therapy drug should follow that drug's instructions and check with their care team before using any light device. If you take a medicine that makes you sensitive to light, ask your prescriber or pharmacist before using a light device. A 2014 review (Kerstein 2014) found four publications on laser treatment in people taking light-sensitizing medicines, and none reported a complication, which is too little evidence to show either harm or safety.[30]

Administration Methods

At-home and in-clinic red light devices differ in how they are used.

At-home red light devices usually deliver low-power light over repeated sessions of several minutes, while clinic lasers deliver a set dose of energy to specific points. Trial results are tied to the dose used, and a higher dose is not always better. Settings reported in different studies cannot be compared directly without knowing the area treated, the distance from the skin and the number of sessions. Results from one type of device, such as a clinic laser, do not automatically apply to another, such as an at-home LED mask.

The settings in this table are those reported in the studies named in each row, and they are not instructions to follow.

Settings reported in different studies cannot be compared directly without knowing the area treated, the distance from the skin and the number of sessions. In these tables, Not published means that in searches of Europe PMC, PubMed and ClinicalTrials.gov on October 1, 2026 we found no published data for that cell.

Are red light therapy devices FDA-cleared, and for which uses?

Red light therapy devices sold for medical uses are FDA-regulated medical devices; clearance covers specific products and uses, not every use offered.

Red light therapy devices sold for medical uses are regulated by FDA as medical devices (Class II). The HairMax LaserComb (Lexington International, K060305) was cleared through FDA's 510(k) process for over-the-counter use: 'The LaserComb is indicated to promote hair growth in males with androgenetic alopecia who have Norwood Hamilton Classifications of IIa to V and Fitzpatrick Skin Types I to IV.'

Red light therapy devices sold for medical uses are regulated by FDA as medical devices (Class II). The Red Light Hair Growth Cap, model LP-RJVGRW-BLK (Shenzhen Idea Light Limited, K250467), was cleared through FDA's 510(k) process for over-the-counter use: 'The Red Light Hair Growth Cap is indicated to treat Androgenetic Alopecia and promote hair growth in males who have Norwood-Hamilton Classifications of IIa-V patterns of hair loss and to treat Androgenetic Alopecia and promote hair growth in females who have Ludwig-Savin Scale I-1 to I-4, II-1, II-2 or frontal patterns of hair loss; both with Fitzpatrick Skin Types I-IV.'

Red light therapy devices sold for medical uses are regulated by FDA as medical devices (Class II). The MR5 Activ Pro (Multi Radiance Medical, K254024) was cleared through FDA's 510(k) process for prescription use: 'The MR5 ACTIV PRO is indicated for adjunctive use in the temporary relief of pain associated with Lateral Epicondylitis.'

Red light therapy devices sold for medical uses are regulated by FDA as medical devices (Class II). The LED Lip Perfector, model ZC-05 (Light Tree Ventures Europe B.V., K223642), was cleared through FDA's 510(k) process for over-the-counter use: 'The LED Lip Perfector (Model: ZC-05) is an Over-the-Counter (OTC) device intended to treat fine lines and wrinkles and increase in circulation within the perioral region.'

Red light therapy devices sold for medical uses are regulated by FDA as medical devices (Class II). The CurrentBody Skin LED Multi Light Therapy Mask, model MK-110D (The Beauty Tech Group, K260715), was cleared through FDA's 510(k) process for over-the-counter use, with separate light modes: 'Mode 1 (including red (633nm), NIR (830nm & 1072nm)) is intended to provide topical heating for the purpose of elevating tissue temperature; for the temporary relief of minor muscle and joint pain, arthritis and muscle spasm; relieving stiffness; promoting the relaxation of muscle tissue; and to temporarily increase local blood circulation.' 'Mode 2 (including blue (415nm) & red (633nm)) is intended for the treatment of mild to moderate inflammatory acne.' 'Mode 3 (including yellow (590nm) & NIR (830nm)) is intended for the treatment of full face wrinkles.' 'The device is intended for use on Fitzpatrick skin types I–IV.'

Regulatory status checked September 28, 2026. Sources: www.govinfo.gov/…/CFR-2025-title21-vol8-sec890-5500.xml; www.govinfo.gov/…/CFR-2025-title21-vol8-sec878-4810.xml; www.govinfo.gov/…/CFR-2025-title21-vol8-sec807-97.xml; www.accessdata.fda.gov/…/K060305.pdf; www.accessdata.fda.gov/…/K250467.pdf; www.accessdata.fda.gov/…/K254024.pdf; www.accessdata.fda.gov/…/K163079.pdf; www.accessdata.fda.gov/…/K223642.pdf; www.accessdata.fda.gov/…/K260715.pdf; www.accessdata.fda.gov/…/DEN230083.pdf; www.fda.gov/…/photobiomodulation-pbm-devices-premarket-notification-510k-submissions

Provider Directory

Find a Provider

A licensed clinician decides whether treatment is appropriate. Treatment is not guaranteed.