‘It seems like sorcery’: is light therapy truly capable of improving your skin, whitening your teeth, and strengthening your joints?
Phototherapy is definitely experiencing a moment. You can now buy glowing gadgets for everything from dermatological concerns and fine lines along with sore muscles and oral inflammation, the latest being an oral care tool enhanced with small red light diodes, marketed by the company as “a breakthrough in at-home oral care.” Worldwide, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. Options include full-body infrared sauna sessions, where instead of hot coals (real or electric) heating the air, the thermal energy targets your tissues immediately. Based on supporter testimonials, it’s like bathing in one of those LED-lit beauty masks, stimulating skin elasticity, easing muscle tension, reducing swelling and persistent medical issues and potentially guarding against cognitive decline.
The Science and Skepticism
“It sounds a bit like witchcraft,” says a Durham University professor, who has researched light therapy for two decades. Of course, we know light influences biological functions. Sunlight helps us make vitamin D, needed for bone health, immunity, muscles and more. Light exposure controls our sleep-wake cycles, additionally, triggering the release of neurochemicals and hormones while we are awake, and preparing the body for rest as darkness falls. Daylight-simulating devices are standard treatment for winter mood disorders to boost low mood in winter. Undoubtedly, light plays a vital role in human health.
Types of Light Therapy
Whereas seasonal affective disorder devices typically employ blue-range light, most other light therapy devices deploy red or infrared light. During advanced medical investigations, such as Chazot’s investigations into the effects of infrared on brain cells, identifying the optimal wavelength is crucial. Light is a form of electromagnetic radiation, spanning from low-energy radio waves to short-wavelength gamma rays. Light-based treatment uses wavelengths around the middle of this spectrum, the highest energy of those being invisible ultraviolet, then visible light (all the colours we see in a rainbow) and then infrared (which we can see with night-vision goggles).
Dermatologists have utilized UV therapy for extensive periods to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It affects cellular immune responses, “and reduces inflammatory processes,” notes a skin specialist. “Considerable data validates phototherapy.” UVA penetrates skin more deeply than UVB, whereas the LEDs we see on consumer light-therapy devices (usually producing colored light emissions) “tend to be a bit more superficial.”
Safety Considerations and Medical Oversight
UVB radiation effects, like erythema or pigmentation, are recognized but medical equipment uses controlled narrow-band delivery – meaning smaller wavelengths – that reduces potential hazards. “Treatment is monitored by medical staff, meaning intensity is regulated,” notes the specialist. And crucially, the light sources are adjusted by technical experts, “to guarantee appropriate wavelength emission – unlike in tanning salons, where regulations may be lax, and we don’t really know what wavelengths are being used.”
Home Devices and Scientific Uncertainty
Red and blue LEDs, he says, “aren’t typically employed clinically, but could assist with specific concerns.” Red light devices, some suggest, help boost blood circulation, oxygen uptake and skin cell regeneration, and activate collagen formation – a key aspiration in anti-ageing effects. “Studies are available,” states the dermatologist. “Although it’s not strong.” In any case, amid the sea of devices now available, “it’s unclear if device outputs match study parameters. Optimal treatment times are unknown, proper positioning requirements, the risk-benefit ratio. Many uncertainties remain.”
Treatment Areas and Specialist Views
Initial blue-light devices addressed acne bacteria, a microbe associated with acne. Scientific backing remains inadequate for regular prescription – even though, explains the specialist, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he mentions, however for consumer products, “we advise cautious experimentation and safety verification. Unless it’s a medical device, the regulation is a bit grey.”
Innovative Investigations and Molecular Effects
Simultaneously, in advanced research areas, 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. The numerous reported benefits have generated doubt regarding phototherapy – that claims seem exaggerated. However, scientific investigation has altered his perspective.
Chazot mostly works on developing drug treatments for neurodegenerative diseases, but over 20 years ago, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He designed tools for biological testing,” he says. “I was pretty sceptical. This particular frequency was around 1070 nanometers, which most thought had no biological effect.”
Its beneficial characteristic, though, was that it travelled through water easily, allowing substantial bodily penetration.
Mitochondrial Effects and Brain Health
More evidence was emerging at the time that infrared light targeted the mitochondria in cells. Mitochondria are the powerhouses of cells, generating energy for them to function. “All human cells contain mitochondria, even within brain tissue,” says Chazot, who, as a neuroscientist, decided to focus the research on brain cells. “Studies demonstrate enhanced cerebral circulation with light treatment, which is always very good.”
With specific frequency application, cellular power plants create limited oxidative molecules. At controlled levels these compounds, explains the expert, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”
Such mechanisms indicate hope for cognitive disorders: oxidative protection, inflammation reduction, and pro-autophagy – autophagy representing cellular waste disposal.
Current Research Status and Professional Opinions
Upon examining current studies on light therapy for dementia, he reports, approximately 400 participants enrolled in multiple trials, including his own initial clinical trials in the US
