Explainer | What is LED therapy? How red, blue and infrared light benefit both skin and body

Not too long ago, Victoria Beckham posted a photo of herself on Instagram lying on a bed with a shield over her face that emitted a blue glow. “More is more with my skincare routine!” read the caption. The therapy – known as LED (light-emitting diode) therapy – is a relatively recent arrival on the wellness and beauty scene, one that is used to treat a variety of skin conditions: from acne and scarring to stretch marks and psoriasis. The therapy – which many people may have heard called “red light therapy” as the term is becoming increasingly popular – is also used to reduce the telltale signs of ageing by plumping skin and reducing the appearance of fine lines. As well as Beckham, it is popular with A-list celebrities such as Kim and Kourtney Kardashian, Jennifer Aniston, Gwyneth Paltrow, and Madonna. But how does light therapy work? LED therapy can include LED diodes of many colours, including yellow and green light, but red and blue are the most common. The non-surgical treatment uses different wavelengths of light to penetrate the skin – a process called photobiomodulation. Cells absorb the light, which activates photoreceptors, in turn increasing the production of adenosine triphosphate (ATP) – the main energy-carrying molecule in living cells. This increase in ATP helps the body’s cells repair themselves. LED therapy benefits the complexion in many ways. It stimulates collagen and the production of elastin – hence its anti-ageing effect – reduces inflammation, eases rosacea and eradicates bacteria that cause spots and acne. Blue light penetrates the outer layer of the skin and helps kill bacteria and staunch oil production. Red light goes deeper and stimulates fibroblasts – the cells in connective tissues that provide structural support. Near-infrared light penetrates deeper still to enhance circulation. Nasa began using LEDs in plant-growth experiments – with red leaf lettuce and wheat – on space missions in the early 1990s. This research led to the discovery that LED light could stimulate cell and tissue repair in astronauts who suffered bone density loss and muscle atrophy in space. Astronauts are three times more likely to injure themselves in orbit than on Earth, and red light therapy was found to speed up healing. As a result, red light therapy is increasingly being harnessed as a treatment for many conditions, such as burns, which affect about 6 million people globally each year. Red light therapy has also shown promise in treating people with diabetes who have a specific vulnerability to chronic wounds and slow healing. Because of its anti-inflammatory and pain-relieving effects, red light therapy is also being used as a treatment for conditions involving chronic pain, such as rheumatoid arthritis, carpal tunnel syndrome and tendinitis. Red light therapy works to improve blood flow and balance the production of cytokines. An imbalance between pro-inflammatory cytokines and anti-inflammatory cytokines leads to inflammation and joint damage. Dr Corinne Koo, founder of Hong Kong wellness centre Harmony Central, understands red light therapy well. Her own story shows the potential of the therapy. Fifteen years ago, Koo, who was a dentist at the time, was diagnosed with Parkinson’s disease. Unable to continue working as a dentist, she did a degree in behavioural health and began to explore complementary treatments. It was then that she came across LED red light therapy. She describes an innovative study that began in Tasmania, Australia. Researchers put red LED lights in buckets as makeshift helmets for Parkinson’s patients to wear, “like a lampshade”, she laughs. After some time, patients began to record improvements in their sense of smell, mood, sleep and fine motor skills. This work spurred further research in Australia and the US. Koo began to suffer a great deal of joint pain after getting Covid-19 vaccinations, probably caused by localised inflammation. The discomfort made her unable to sleep through the night. She started using a red light mat – a flat, red-light-emitting device – for 20 minutes three times a week and immediately noticed a difference. “It didn’t cure me, but it gave me enough relief that I could sleep through the night, and because it released muscles, it meant I could walk with less pain and move more freely,” she says. Her son – who plays tennis at a high level – uses an LED red light mat for sports injuries, as do his tennis-playing friends. Koo is passionate about helping people understand how red light therapy works and equipping them with the knowledge to manage treatments at home. She knows it will not cure her Parkinson’s, but it can make living with the condition easier. However, she worries about the therapy being touted as a cure-all, especially for cancer. “I had a client with stage-four cancer who was recommended by a vendor to buy a full-body red light therapy mat and to sleep on it every night for many hours. This is what people have to be careful about,” she says. She adds that, while LEDs’ effect on cell stimulation and growth is beneficial for healing and regeneration, some studies suggest that red light therapy could potentially promote tumour cell proliferation. She says that international guidelines do not recommend applying it directly over known locations of tumours, though it is clinically endorsed for relieving side effects of cancer treatment. Oral mucositis – a painful inflammation and ulceration of the mucous membranes in the mouth often caused by chemotherapy and radiation to the head and neck – has been eased by red light therapy; it can reduce pain and swelling and prompt healing of lesions in the mouth. Lymphoedema – a condition involving painful swelling of the arms – often develops after breast cancer treatment that damages or removes lymph nodes. Red light therapy can help manage the condition by encouraging lymph movement, softening tissues and helping alleviate pain to make movement easier. Koo says that at low, carefully controlled doses, red light can stimulate repair, reduce inflammation and enhance cell function. However, the fact that the therapy’s main action is photochemical rather than thermal – meaning users do not usually sense the lights’ heat – can pose problems. At a cellular level, light absorption can generate a subtle heat increase, especially under higher intensity or prolonged exposure. In my experience, this can reduce treatment effectiveness,” Koo says. “If exposure is too intense or too long, the benefits can plateau or even reverse, stressing the cells instead of helping them.” Koo uses a great analogy, comparing LED therapy to the sun: a little is good for you; too much can be harmful. “That’s why I caution that prolonged, unsupervised, high-dose use may not only blunt the benefits but could also pose risks. The key is balance – finding that sweet spot where the light provides repair without overheating the delicate cellular machinery,” she says. Koo finds from her own experience that using red light therapy about three times a week for 10 minutes brings noticeable benefits for her condition. She stresses, however, that this is a personal routine, not a medical prescription – the ideal dose, frequency and intensity vary widely depending on the individual, their condition and their sensitivity to light. “There is no one-size-fits-all approach, and proper guidance is key.” Koo says that although the American Academy of Dermatology Association deems red-light devices safe, “we don’t know the long-term effects on the skin or hair. More research is needed to find out”. Beauty and skincare are where the money is, she adds, but the potential scope and benefit of properly prescribed LED therapy goes much more than skin deep. Like what you read? Follow SCMP Lifestyle on Facebook, X and Instagram. You can also sign up for our eNewsletter here.

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Victoria Beckham and Kim Kardashian use LED light therapy for skincare, but it also has anti-inflammatory and pain-relieving health effects

Victoria Beckham and Kim Kardashian use LED light therapy for skincare, but it also has anti-inflammatory and pain-relieving health effects