‘It seems like sorcery’: is light therapy truly capable of improving your skin, whitening your teeth, and strengthening your joints?

Phototherapy is certainly having a wave of attention. You can now buy light-emitting tools targeting issues like skin conditions and wrinkles to sore muscles and oral inflammation, the latest being a dental hygiene device outfitted with tiny red LEDs, described by its makers as “a major advance in at-home oral care.” Globally, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. There are even infrared saunas available, which use infrared light to warm the body directly, the infrared radiation heats your body itself. Based on supporter testimonials, the experience resembles using an LED facial mask, boosting skin collagen, soothing sore muscles, reducing swelling and persistent medical issues while protecting against dementia.

Understanding the Evidence

“It sounds a bit like witchcraft,” notes a Durham University professor, a scientist who has studied phototherapy extensively. Naturally, some of light’s effects on our bodies are well established. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Natural light synchronizes our biological clocks, as well, activating brain chemicals and hormonal responses in daylight, and winding down bodily functions for sleep as it fades into night. Sunlight-imitating lamps are a common remedy for people with seasonal affective disorder (Sad) to combat seasonal emotional slumps. Undoubtedly, light plays a vital role in human health.

Types of Light Therapy

Whereas seasonal affective disorder devices typically employ blue-range light, the majority of phototherapy tools use red or near-infrared wavelengths. In rigorous scientific studies, including research on infrared’s impact on neural cells, determining the precise frequency is essential. Light is a form of electromagnetic radiation, extending from long-wavelength radiation to high-energy gamma radiation. Light-based treatment employs mid-spectrum wavelengths, 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).

UV light has been used by medical dermatologists for many years for addressing long-term dermatological issues like vitiligo. It affects cellular immune responses, “and reduces inflammatory processes,” notes a dermatology expert. “Considerable data validates phototherapy.” UVA goes deeper into the skin than UVB, whereas the LEDs we see on consumer light-therapy devices (usually producing colored light emissions) “typically have shallower penetration.”

Safety Protocols and Medical Guidance

Potential UVB consequences, such as burning or tanning, are well known but in medical devices the light is delivered in a “narrow-band” form – indicating limited wavelength spectrum – which minimises the risks. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” explains the dermatologist. Most importantly, the devices are tuned by qualified personnel, “to confirm suitable light frequency output – as opposed to commercial tanning facilities, where oversight might be limited, and wavelength accuracy isn’t verified.”

Commercial Products and Research Limitations

Red and blue light sources, he says, “aren’t typically employed clinically, though they might benefit some issues.” Red light devices, some suggest, enhance blood flow, oxygen uptake and skin cell regeneration, and promote collagen synthesis – an important goal for anti-aging. “Research exists,” says Ho. “But it’s not conclusive.” Regardless, with numerous products on the market, “we’re uncertain whether commercial devices replicate research conditions. Optimal treatment times are unknown, proper positioning requirements, the risk-benefit ratio. Many uncertainties remain.”

Targeted Uses and Expert Opinions

One of the earliest blue-light products targeted Cutibacterium acnes, a microbe associated with acne. Scientific backing remains inadequate for regular prescription – although, notes the dermatologist, “it’s frequently employed in beauty centers.” Some of his patients use it as part of their routine, he says, but if they’re buying a device for home use, “we advise cautious experimentation and safety verification. If it’s not medically certified, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

Simultaneously, in innovative scientific domains, Chazot has been experimenting with brain cells, discovering multiple mechanisms for infrared’s cellular benefits. “Virtually all experiments with specific wavelengths showed beneficial and safeguarding effects,” he says. The numerous reported benefits have generated doubt regarding phototherapy – that claims seem exaggerated. Yet, experimental evidence has transformed his viewpoint.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, however two decades past, 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 explains. “I remained doubtful. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

The advantage it possessed, however, was its efficient water penetration, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. These organelles generate cellular energy, generating energy for them to function. “Mitochondria exist throughout the body, particularly in neural cells,” says Chazot, who, as a neuroscientist, decided to focus the research on brain cells. “It has been shown that in humans this light therapy increases blood flow into the brain, which is generally advantageous.”

With 1070 treatment, cellular power plants create limited oxidative molecules. In limited quantities these molecules, says Chazot, “triggers guardian proteins that maintain organelle health, look after your cells and also deal with the unwanted proteins.”

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

Ongoing Study Progress and Specialist Evaluations

Upon examining current studies on light therapy for dementia, he states, approximately 400 participants enrolled in multiple trials, comprising his early research projects