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

Phototherapy is clearly enjoying a surge in popularity. You can now buy illuminated devices designed to address complexion problems and aging signs to sore muscles and periodontal issues, recently introduced is a toothbrush equipped with small red light diodes, described by its makers 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. There are even infrared saunas available, where instead of hot coals (real or electric) heating the air, the thermal energy targets your tissues immediately. According to its devotees, it’s like bathing in one of those LED-lit beauty masks, enhancing collagen production, relaxing muscles, relieving inflammation and chronic health conditions as well as supporting brain health.

Understanding the Evidence

“It sounds a bit like witchcraft,” says a Durham University professor, a scientist who has studied phototherapy extensively. Certainly, we know light influences biological functions. Our bodies produce vitamin D through sun exposure, needed for bone health, immunity, muscles and more. Sunlight regulates our circadian rhythms, too, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Sunlight-imitating lamps are standard treatment for winter mood disorders to boost low mood in winter. Clearly, light energy is essential for optimal functioning.

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, like examinations of infrared influence on cerebral tissue, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, which runs the spectrum from the lowest-energy, longest wavelengths (radio waves) to high-energy gamma radiation. Light-based treatment employs mid-spectrum wavelengths, including invisible ultraviolet radiation, then visible light (all the colours we see in a rainbow) and finally infrared detectable with special equipment.

Ultraviolet treatment has been employed by skin specialists for decades to manage persistent skin disorders including eczema and psoriasis. It works on the immune system within cells, “and suppresses swelling,” says a skin specialist. “Substantial research supports light therapy.” UVA goes deeper into the skin than UVB, while the LEDs in consumer devices (usually producing colored light emissions) “typically have shallower penetration.”

Risk Assessment and Professional Supervision

Potential UVB consequences, including sunburn or skin darkening, are recognized but medical equipment uses controlled narrow-band delivery – meaning smaller wavelengths – which decreases danger. “Therapy is overseen by qualified practitioners, meaning intensity is regulated,” explains the dermatologist. And crucially, the devices are tuned by qualified personnel, “to guarantee appropriate wavelength emission – as opposed to commercial tanning facilities, where oversight might be limited, and emission spectra aren’t confirmed.”

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, improve circulatory function, oxygen absorption and skin cell regeneration, and activate collagen formation – a key aspiration in anti-ageing effects. “The evidence is there,” comments the expert. “However, it’s limited.” Regardless, given the plethora of available tools, “we’re uncertain whether commercial devices replicate research conditions. We don’t know the duration, how close the lights should be to the skin, if benefits outweigh potential risks. There are lots of questions.”

Specific Applications and Professional Perspectives

Early blue-light applications focused on skin microbes, microorganisms connected to breakouts. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – despite the fact that, explains the specialist, “it’s commonly used in cosmetic clinics.” Individuals include it in their skincare practices, he mentions, though when purchasing home devices, “we advise cautious experimentation and safety verification. Unless it’s a medical device, oversight remains ambiguous.”

Innovative Investigations and Molecular Effects

Meanwhile, in advanced research areas, researchers have been testing neural cells, identifying a number of ways in which infrared can boost cellular health. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he states. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that claims seem exaggerated. Yet, experimental evidence has transformed his viewpoint.

The scientist mainly develops medications for neurological conditions, though twenty years earlier, a physician creating light-based cold sore therapy requested his biological knowledge. “He developed equipment for cellular and insect experiments,” he recalls. “I remained doubtful. It was an unusual wavelength of about 1070 nanometres, which most thought had no biological effect.”

What it did have going for it, though, was its efficient water penetration, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. Mitochondria produce ATP for cell function, producing fuel for biological processes. “Mitochondria exist throughout the body, including the brain,” notes the researcher, who concentrated on cerebral applications. “Research confirms improved brain blood flow with phototherapy, which is consistently beneficial.”

With 1070 treatment, 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.”

All of these mechanisms appear promising for treating a brain disease: antioxidant, 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 states, about 400 people were taking part in four studies, including his own initial clinical trials in the US