‘It sounds like witchcraft’: can light therapy really give you better skin, cleaner teeth, stronger joints?

Light therapy is certainly having a moment. You can now buy illuminated devices designed to address skin conditions and wrinkles as well as aching tissues and oral inflammation, the newest innovation is a toothbrush outfitted with tiny red LEDs, marketed by the company as “a significant discovery in at-home oral care.” Internationally, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. Options include full-body infrared sauna sessions, that employ light waves rather than traditional heat sources, the infrared radiation heats your body itself. According to its devotees, the experience resembles using an LED facial mask, stimulating skin elasticity, relaxing muscles, reducing swelling and long-term ailments as well as supporting brain health.

Understanding the Evidence

“It sounds a bit like witchcraft,” says a Durham University professor, who has researched light therapy for two decades. Naturally, we know light influences biological functions. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Light exposure controls our sleep-wake cycles, additionally, activating brain chemicals and hormonal responses in daylight, and signaling the body to slow down for nighttime. Daylight-simulating devices are standard treatment for winter mood disorders to combat seasonal emotional slumps. Clearly, light energy is essential for optimal functioning.

Types of Light Therapy

Although mood lamps generally utilize blue-spectrum frequencies, most other light therapy devices deploy red or infrared light. In serious clinical research, such as Chazot’s investigations into the effects of infrared on brain cells, finding the right frequency is key. Light constitutes electromagnetic energy, extending from long-wavelength radiation to short-wavelength gamma rays. Phototherapy, or light therapy uses wavelengths around the middle of this spectrum, with ultraviolet representing the higher energy invisible light, then visible light (all the colours we see in a rainbow) and then infrared (which we can see with night-vision goggles).

Ultraviolet treatment has been employed by skin specialists for decades for addressing long-term dermatological issues like vitiligo. It affects cellular immune responses, “and suppresses swelling,” notes Dr Bernard Ho. “Substantial research supports light therapy.” UVA reaches deeper skin layers compared to UVB, while the LEDs in consumer devices (typically emitting red, infrared or blue wavelengths) “typically have shallower penetration.”

Safety Protocols and Medical Guidance

UVB radiation effects, such as burning or tanning, are recognized but medical equipment uses controlled narrow-band delivery – signifying focused frequency bands – that reduces potential hazards. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” explains the dermatologist. Essentially, the devices are tuned by qualified personnel, “to ensure that the wavelength that’s being delivered is fit for purpose – unlike in tanning salons, where it’s a bit unregulated, and wavelength accuracy isn’t verified.”

Home Devices and Scientific Uncertainty

Red and blue LEDs, he says, “don’t have strong medical applications, but could assist with specific concerns.” Red light devices, some suggest, enhance blood flow, oxygen absorption and dermal rejuvenation, and activate collagen formation – a key aspiration in anti-ageing effects. “Research exists,” states the dermatologist. “But it’s not conclusive.” In any case, amid the sea of devices now available, “we’re uncertain whether commercial devices replicate research conditions. Optimal treatment times are unknown, ideal distance from skin surface, whether or not that will increase the risk versus the benefit. Many uncertainties remain.”

Treatment Areas and Specialist Views

Early blue-light applications focused on skin microbes, bacteria linked to pimples. Research support isn’t sufficient for standard medical recommendation – although, says Ho, “it’s frequently employed in beauty centers.” Individuals include it in their skincare practices, he mentions, but if they’re buying a device for home use, “we advise cautious experimentation and safety verification. Unless it’s a medical device, the regulation is a bit grey.”

Cutting-Edge Studies and Biological Processes

At the same time, in innovative scientific domains, researchers have been testing neural cells, discovering multiple mechanisms for infrared’s cellular benefits. “Pretty much everything I did with the light at that particular wavelength was positive and protective,” he reports. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that it’s too good to be true. However, scientific investigation has altered his perspective.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, though twenty years earlier, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He developed equipment for cellular and insect experiments,” he recalls. “I was quite suspicious. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

Its beneficial characteristic, nevertheless, was its efficient water penetration, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Growing data suggested infrared influenced energy-producing organelles. Mitochondria produce ATP for cell function, creating power for cellular operations. “Every cell in your body has mitochondria, even within brain tissue,” explains the neuroscientist, who prioritized neurological investigations. “It has been shown that in humans this light therapy increases blood flow into the brain, which is generally advantageous.”

With specific frequency application, energy organelles generate minimal reactive oxygen compounds. In limited quantities these molecules, says Chazot, “stimulates so-called chaperone proteins which look after your mitochondria, look after your cells and also deal with the unwanted proteins.”

All of these mechanisms appear promising for treating a brain disease: oxidative protection, swelling control, and waste removal – self-digestion mechanisms eliminating harmful elements.

Ongoing Study Progress and Specialist Evaluations

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he reports, approximately 400 participants enrolled in multiple trials, comprising his early research projects