![\"\"](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/22182215\/SEI_2940320381.jpg\")
<\/div>George Dagerotip\/Unsplash<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
Better sleep, boosted mood, fewer wrinkles \u2013 these are just a handful of the supposed benefits of red light, delivered onto your skin via laser or light-emitting diodes (LEDs). Indeed, if the wellness industry is to be believed, simply bathing in a rosy glow for a few minutes a day can cure a whole host of ailments, from hair loss and acne to chronic pain and depression, and that is just scratching the surface.<\/p>\n
Given the hype, you\u00a0would be forgiven for thinking this is just an expensive fad. After all, if something sounds too good to be true, it\u00a0probably is.<\/p>\n
While evidence for most of these claims is thin at best,\u00a0there is\u00a0another world\u00a0of\u00a0red-light therapy that is far more exciting\u00a0than the prospect of a glow-up.\u00a0Emerging\u00a0evidence finds it may mitigate cognitive decline, and researchers are now trialling the technology for conditions such as Alzheimer\u2019s and Parkinson\u2019s, with many more applications in the pipeline.\u00a0\u201cIt\u2019s slowly starting to get traction,\u201d says\u00a0John Mitrofanis at the University of Grenoble Alpes in France, who has been working on red-light therapy for 15 years. \u201cWhen I started, there might have been 10 or 20 publications a year,\u00a0but now there\u00a0are\u00a0thousands.\u201d\u00a0\u00a0<\/strong><\/p>\n Using electromagnetic radiation is commonplace in medicine. Doctors routinely deploy X-rays to peer at bones and ultraviolet light to ease certain skin conditions. Yet unlike these, red light falls within the visible spectrum, the narrow band of wavelengths detectable by the human eye. Its wavelengths are longer than other visible lights, like blue or green light, spanning between around 650 and 750 nanometres. This allows it to pass through the dead outer layer of our skin, penetrating a few millimetres beneath. The longer the wavelength, the deeper it travels.<\/p>\n <\/p>\n Once consigned to dermatologist offices and spas, red-light therapy is now readily available via consumer devices such as face masks and full-body panels. Influencers peddle it on social media, and the US Food and Drug Administration has cleared devices for acne and hair loss, though they\u00a0aren\u2019t\u00a0yet approved as clinically effective.<\/p>\n Yet research on red-light therapy goes back to 1960, with the invention of the laser. Biomedical researchers quickly wondered whether these narrow beams of light had medical applications. They soon got their answer.<\/p>\n In 1967, the\u00a0physicist\u00a0Endre Mester at Semmelweis University in Budapest, Hungary,\u00a0shone\u00a0red\u00a0lasers\u00a0with a wavelength of\u00a0694 nanometres\u00a0onto shaved mice\u00a0to see\u00a0if it\u00a0triggered\u00a0skin cancer. It\u00a0didn\u2019t\u00a0\u2013 instead,\u00a0it\u00a0caused\u00a0their fur to grow back\u00a0more\u00a0vigorously.<\/p>\n Mester later discovered the lasers enhanced wound healing and started using them to treat ulcers and other intractable wounds in people. A new branch of medicine, which Mester called low-level laser therapy (LLLT), was born. Other scientists discovered the light doesn\u2019t have to be visible: near-infrared with wavelengths between 700 and 850 nanometres, just beyond the visible spectrum, also had healing effects. LEDs could also be used instead of lasers.<\/p>\n The science behind\u00a0LLLT \u2013\u00a0now rebranded as\u00a0photobiomodulation\u00a0\u2013\u00a0isn\u2019t\u00a0fully understood,\u00a0but we have the basics, says\u00a0Glen\u00a0Jeffery\u00a0at University College London. When red or near-infrared light strikes the skin, it\u00a0acts on\u00a0specialised structures\u00a0in underlying cells\u00a0called mitochondria. It is here \u2013 the power packs of cells \u2013 that the light does its scintillating work.<\/p>\n Mitochondria\u00a0contain\u00a0light-absorbing molecules called chromophores. One,\u00a0cytochrome\u00a0c\u00a0oxidase, is especially important.\u00a0It is a key\u00a0component\u00a0in\u00a0the pathway\u00a0that\u00a0cells use to produce\u00a0the\u00a0energy-carrying molecule\u00a0ATP. Absorbing red or\u00a0near-infrared\u00a0light stimulates cytochrome\u00a0c\u00a0oxidase,\u00a0speeding up the process\u00a0and producing more ATP.<\/p>\n This is beneficial for\u00a0several\u00a0reasons. As we get older,\u00a0mitochondria\u2019s efficiency\u00a0dwindles, and with it,\u00a0their\u00a0ability to produce sufficient energy. \u201cBy the time you reach middle age, you\u2019ve generally got an ATP deficit,\u201d\u00a0says Jeffery.<\/p>\n This has another downside: the overproduction of reactive oxygen species \u2013 volatile chemicals that wreak havoc on nearby cells, spurring inflammation. \u201cBy the time you\u2019re 30, you\u2019ve got systemic inflammation, and systemic inflammation is one of those things that\u2019s going to kill you in the end,\u201d says Jeffery. It contributes to all manner of chronic illnesses, including diabetes, heart disease and cancer.<\/p>\n Red light speeds up the process by which cells produce energy<\/p>\n Bakhrom Tursunov\/Alamy<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n Stimulating mitochondria with red light makes up the ATP deficit and dials down\u00a0reactive oxygen species\u00a0\u2013 in other words,\u00a0it\u00a0rejuvenates.\u00a0It\u00a0also stimulates natural anti-inflammatory molecules,\u00a0such as prostaglandins.\u00a0\u201cUnquestionably ATP goes up,\u201d says Jeffery. \u201cUnquestionably inflammation goes down.\u201d\u00a0It\u2019s\u00a0win, win.<\/p>\n The process\u00a0also\u00a0appears to boost\u00a0a mechanism by which cells heal one another,\u00a0called the biophoton effect.\u00a0Cells produce light, particularly in their mitochondria, and use it to communicate with\u00a0each\u00a0other.\u00a0\u201cCells in distress issue\u00a0ultraviolet\u00a0or blue light. But if\u00a0it\u2019s\u00a0happy and healthy,\u00a0it\u2019ll\u00a0be red and\u00a0near-infrared,\u201d says\u00a0Mitrofanis. \u201cThey use this light to repair each other. If a cell is dying,\u00a0it communicates this,\u00a0and then nearby cells give it red and near-infrared light.\u201d<\/p>\n Exogenous light\u00a0can\u00a0profoundly affect\u00a0energy metabolism. In 2024,\u00a0Jeffery and his colleague\u00a0Michael Powner at City St George\u2019s, University of London, shone red light onto a small area of the upper backs of 15 people without underlying health conditions. The participants then drank sugary water and underwent periodic blood-sugar testing over the next 2 hours. On average, blood sugar was nearly\u00a028 per cent lower\u00a0in this group\u00a0than\u00a0in\u00a0a separate group of 15 people\u00a0who\u00a0hadn\u2019t\u00a0received\u00a0red light,\u00a0indicating\u00a0the light had stimulated their mitochondria, helping them\u00a0to\u00a0more efficiently\u00a0convert sugar\u00a0into ATP.<\/p>\n The research also suggests that the effects spread beyond the light-soaked mitochondria, as the small patch of skin cannot account for the large impact, says Jeffery. This may be related to the mysterious abscopal effect, a rare phenomenon in cancer radiotherapy where irradiation of a primary tumour can shrink secondary tumours located elsewhere, he says.<\/p>\n Consumer companies touting red-light therapy for wellness have seized on this scientific explanation. In the early 2000s, plastic surgeons began using it to aid post-operative wound healing, and word spread of its healing powers. Clinics started offering it to people who hadn\u2019t undergone surgery, and the first at-home devices soon followed.<\/p>\n Red-light therapy is now a booming business. According to fashion magazine\u00a0Vogue<\/em>, the global market was worth around $520 million in 2021 and is forecast to reach $800 million by 2031. Salons, spas and gyms increasingly offer it alongside massages and facials. Consumers can buy at-home devices, ranging from hand-held wands and face masks to helmets and blankets, the cheapest of which cost around \u00a3100 ($135), but some go for thousands.<\/p>\n Companies market the products as an easy route to wellness and cosmetic improvement. The list of concerns they are purported to help with includes, but is not limited to, wrinkles, hair loss, acne, stretch marks, inflammation, pain, insomnia, obesity, athletic performance, erectile dysfunction, menstrual cramps, depression, brain fog, infertility and age-related deterioration.<\/p>\n Given the general rejuvenating and energy-burning effects of red light, these claims seem plausible. But in fact, most of them are \u201chighly dubious\u201d, says Jeffery. However, there are some bright spots.<\/p>\n In 2025,\u00a0a team led by dermatologist\u00a0Michelle Pavlis\u00a0at Duke University in North Carolina reviewed\u00a059 studies\u00a0\u2013\u00a0encompassing\u00a0more than 1880 people\u00a0\u2013\u00a0on\u00a0using\u00a0red-light therapy\u00a0to treat\u00a0skin conditions, from actinic cheilitis to acne. When it came to cosmetic use, \u201cthe strongest evidence is for acne, including with some home-use LED devices\u201d, says Pavlis.<\/p>\n Pavlis found the therapy\u00a0can be\u00a0as good as, or sometimes better than,\u00a0standard\u00a0acne\u00a0drug treatments. For instance,\u00a0one study\u00a0showed\u00a012 weeks of red-light therapy\u00a0reduced pimples by 79 per cent, on average. In comparison, an oral antibiotic paired with topical adapalene \u2013 a standard acne treatment \u2013 led to just a 69 per cent reduction. Acne-specific devices often emit blue and red light, as both wavelengths can kill off pimple-causing bacteria.<\/p>\n The review also found the treatment evened out skin tone in people with psoriasis \u2013 an autoimmune condition \u2013 or rosacea, where skin becomes ruddy and bumpy. Both use cases, however, have been tested in only a single clinical trial.<\/p>\n What of wrinkles and general skin rejuvenation? Here the evidence is mixed. In\u00a0the most successful study,\u00a060 per cent of participants\u00a0saw\u00a0fewer\u00a0wrinkles\u00a0and an improvement in overall skin tone, as evaluated by a dermatologist. But\u00a0two other\u00a0studies\u00a0found no\u00a0significant\u00a0improvement at all.<\/p>\n Some studies suggest that red-light therapy may prevent and even reverse hair loss<\/p>\n Martin Parr\/Magnum Photos<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n Hair growth is another area with promise. At any one moment, around 15 per cent of hair follicles are dormant, which precedes hair falling out. The vigorous fur regrowth Mester observed in his shaved mice was probably from hair follicles getting a red-light energy boost, jolting those that would have been resting into action.<\/p>\n The same appears\u00a0true in\u00a0humans.\u00a0In a\u00a02020 trial, researchers in South Korea used a helmet to beam red light onto the scalps of 30 adults with androgenetic alopecia, the most common form of hair loss. Participants used the device every other day for 25 minutes, while a separate group of 29 people did so with a mock version. After 16 weeks, hair density in those who got the real deal increased more than 57 per cent, on average, compared with the control group. Their hair strands also thickened, whereas those in the control group thinned. But it isn\u2019t known how long this effect lasts.<\/p>\n Mester\u2019s other application, wound healing, also\u00a0has some backing.\u00a0Many studies have found red and near-infrared light can help heal burns, scars and diabetic foot ulcers. However, most of them included just a handful of participants, meaning the evidence isn\u2019t definitive. Which wavelength works best also isn\u2019t known, though some research points towards the 630-to-660-nanometre range.<\/p>\n Studies have\u00a0even\u00a0shown\u00a0that\u00a0the therapy may\u00a0assist\u00a0with weight loss, especially when combined with diet and exercise. Yet almost all of them had fewer than 100 participants. And claims that red-light therapy can remove fat from specific areas \u2013 known as \u201cspot fat\u201d reduction \u2013 are questionable. In 2016, researchers at Nicolaus Copernicus University in Poland illuminated one side of 24 people\u2019s bellies with a consumer red-light device, leaving the other side untouched. After six sessions, there was no difference\u00a0in fat tissue\u00a0between the two sides.<\/p>\n As for the rest of the purported benefits, forget it. The evidence simply doesn\u2019t exist.<\/p>\n So, does that mean that at-home red light therapies have got the, er, green light? Not necessarily. Even in cases where evidence backs red light, devices vary in how they deliver it, using different wavelengths for different durations, and research hasn\u2019t settled on which combo is best.<\/p>\n More importantly, consumer devices are, on the whole, too powerful, says Jeffery, emitting an order of magnitude more power than the few milliwatts needed to nudge mitochondria. Consumer devices typically deliver 60 milliwatts per square centimetre. But the optimal power is around a tenth of that \u2013 and Jeffery has seen effects at less than 1 milliwatt per square centimetre.<\/p>\n Face masks have become a popular way of delivering red-light therapy<\/p>\n Juli Konia\/Alamy<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n \u201cThe [wellness] industry just loves the concept of more and more power,\u201d says Jeffery. And, in the case of red light, more isn\u2019t better. Turbocharging cellular energy production can gum up the whole system, with potentially serious consequences, including a build-up of those havoc-wreaking reactive oxygen species, he says.<\/p>\n Such an influx might explain why red-light therapy seems to lessen wrinkles. Because these molecules cause inflammation, they may temporarily plump up skin. Jeffery worries that people who use powerful red-light devices regularly are storing up trouble. \u201cWe don\u2019t know what\u2019s going to happen in 10 years\u2019 time,\u201d he says. \u201cMaybe your face is going to drop off.\u201d<\/p>\n When it comes to buying your own red-light device, Jeffery\u2019s advice is: don\u2019t bother. \u201cYou\u2019re doing more harm than good, and you\u2019re wasting money.\u201d<\/p>\n The hype around these potential cosmetic uses has outshone the ways red-light therapy is advancing into mainstream medicine.<\/p>\n More than 200 clinical trials\u00a0have tested the tech for\u00a0treating\u00a015 illnesses. A\u00a02025 review found it showed promise for 12 of them, with the strongest evidence for fibromyalgia, osteoarthritis and cognitive impairment.<\/p>\n Fibromyalgia\u00a0is a poorly\u00a0understood\u00a0condition characterised by\u00a0widespread muscular and skeletal pain, leading to insomnia, fatigue and depression. It has few treatments. Yet the review found red-light therapy can help alleviate its symptoms, including the primary one, pain. It also reduces pain and disability in knee osteoarthritis and, to a lesser degree, improves burning mouth syndrome, neck pain, diabetic foot ulcers and some kinds of tendinopathy. But for six conditions \u2013 rheumatoid arthritis, plantar fasciitis, Achilles tendinopathy, fractures, carpal tunnel syndrome and tinnitus \u2013 there is no effect.<\/p>\n Perhaps most surprisingly, it may slow age-related cognitive impairment. A 2023 review of 11 clinical trials, mostly involving people with Alzheimer\u2019s and Parkinson\u2019s, but also some with traumatic brain injuries, found transcranial near-infrared light most promising. With this in-clinic treatment, light passes through the skull, into outer brain regions. \u201cWe\u2019re talking 20 to 30 millimetres, and that\u2019s certainly enough to get to our best piece of brain,\u201d says Mitrofanis, referring to the cerebral cortex, which carries out functions such as planning and short-term memory. Red-light therapy can\u2019t cure or even halt cognitive decline, but it could\u00a0potentially\u00a0decelerate its progression, probably through boosting energy production in struggling brain cells.<\/p>\n While positive, the evidence remains uneven, with studies ranging from single sessions up to 72, each lasting between 30 seconds and 30 minutes. This underscores the need for larger, more standardised trials, some of which are already under way.<\/p>\n Mitrofanis and his colleagues are trialling an optical fibre that delivers near-infrared light deep into brain regions affected by Parkinson\u2019s disease. He is also investigating its treatment potential for traumatic brain injury, stroke, Lewy body dementia and depression, and preliminary results are encouraging. \u201cThe patients felt better, their get-up-and-go was better, they had less fatigue, their mood was better,\u201d he says. \u201cBut there is a long way to go.\u201d The technology must still undergo multiple clinical trials, and researchers must pinpoint the best delivery method for each condition.<\/p>\n If that pans out, in the long term, the sky may be the limit. \u201cThis thing will potentially help any cell that\u2019s in distress as long as it\u2019s not too far in distress,\u201d says Mitrofanis. \u201cIf mitochondria are too damaged, nothing will save [them]. But if you\u2019ve got early signs of distress \u2013 the mitochondria are starting to get a bit wobbly \u2013 then you can save it.\u201d<\/p>\n In other words, red-light therapy might help any condition in which cells are struggling \u2013 which is many of them. It may not be too long before we are all basking in a red glow, not because of social media hype, but because it is doctor\u2019s orders.<\/p>\n Topics:<\/p>\n<\/section><\/div>\n\n","protected":false},"excerpt":{"rendered":" George Dagerotip\/Unsplash Better sleep, boosted mood, fewer wrinkles \u2013 these are just a handful of the supposed benefits of red light, delivered onto your skin via...<\/p>\n","protected":false},"author":1,"featured_media":2652,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/22182215\/SEI_2940320381.jpg","fifu_image_alt":"","footnotes":""},"categories":[1],"tags":[2303,695,2302,2301],"class_list":["post-2651","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-rj","tag-ageing","tag-health","tag-medical-technology","tag-skin"],"_links":{"self":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts\/2651","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2651"}],"version-history":[{"count":0,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts\/2651\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/media\/2652"}],"wp:attachment":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2651"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2651"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2651"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Lighten up<\/h2>\n
![\"\"](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/22175255\/SEI_294032615.jpg\")
<\/div>Healing at home?<\/h2>\n
![\"A](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/22175150\/SEI_294032811.jpg\")
<\/div>![\"A](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/22175304\/SEI_294032591.jpg\")
<\/div>Beyond aesthetics<\/h2>\n