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

Light therapy is definitely experiencing a surge in popularity. You can now buy glowing gadgets targeting issues like skin conditions and wrinkles along with sore muscles and oral inflammation, the newest innovation is a dental hygiene device enhanced with small red light diodes, marketed by the company as “a breakthrough for domestic dental hygiene.” Globally, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. There are even infrared saunas available, that employ light waves rather than traditional heat sources, the thermal energy targets your tissues immediately. According to its devotees, it feels similar to a full-body light therapy session, stimulating skin elasticity, relaxing muscles, relieving inflammation and persistent medical issues and potentially guarding against cognitive decline.

Understanding the Evidence

“It sounds a bit like witchcraft,” notes Paul Chazot, professor in neuroscience at Durham University and a convert to the value of light therapy. Of course, some of light’s effects on our bodies are well established. Sunlight helps us make vitamin D, needed for bone health, immunity, muscles and more. Light exposure controls our sleep-wake cycles, additionally, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Daylight-simulating devices are standard treatment for winter mood disorders to elevate spirits during colder months. So there’s no doubt we need light energy to function well.

Different Light Modalities

Although mood lamps generally utilize blue-spectrum frequencies, most other light therapy devices deploy red or infrared light. In serious clinical research, like examinations of infrared influence on cerebral tissue, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application employs mid-spectrum wavelengths, the highest energy of those being invisible ultraviolet, then visible light (all the colours we see in a rainbow) and infrared light visible through night vision technology.

UV light has been used by medical dermatologists for many years to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It works on the immune system within cells, “and suppresses swelling,” notes a dermatology expert. “Considerable data validates phototherapy.” UVA goes deeper into the skin than UVB, in contrast to LEDs in commercial products (typically emitting red, infrared or blue wavelengths) “typically have shallower penetration.”

Safety Considerations and Medical Oversight

Potential UVB consequences, including sunburn or skin darkening, are understood but clinical devices employ restricted wavelength ranges – signifying focused frequency bands – that reduces potential hazards. “Treatment is monitored by medical staff, so the dosage is monitored,” says Ho. And crucially, the light sources are adjusted by technical experts, “to guarantee appropriate wavelength emission – as opposed to commercial tanning facilities, where oversight might be limited, and wavelength accuracy isn’t verified.”

Home Devices and Scientific Uncertainty

Red and blue light sources, he notes, “aren’t typically employed clinically, but could assist with specific concerns.” Red light devices, some suggest, improve circulatory function, oxygen utilization and dermal rejuvenation, and stimulate collagen production – a primary objective in youth preservation. “Studies are available,” says Ho. “Although it’s not strong.” In any case, given the plethora of available tools, “we don’t know whether or not the lights emitted are reflective of the research that has been done. Optimal treatment times are unknown, proper positioning requirements, if benefits outweigh potential risks. Many uncertainties remain.”

Specific Applications and Professional Perspectives

One of the earliest blue-light products targeted Cutibacterium acnes, bacteria linked to pimples. Research support isn’t sufficient for standard medical recommendation – although, notes the dermatologist, “it’s frequently employed in beauty centers.” Individuals include it in their skincare practices, he observes, but if they’re buying a device for home use, “we recommend careful testing and security confirmation. If it’s not medically certified, the regulation is a bit grey.”

Advanced Research and Cellular Mechanisms

At the same time, in innovative scientific domains, researchers have been testing neural cells, revealing various pathways for light-enhanced cell function. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he reports. Multiple claimed advantages have created skepticism toward light treatment – that claims seem exaggerated. But his research has thoroughly changed his mind in that respect.

The scientist mainly develops medications for neurological conditions, however two decades past, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He created some devices so that we could work with them with cells and with fruit flies,” he says. “I remained doubtful. The specific wavelength measured approximately 1070nm, that many assumed was biologically inert.”

The advantage it possessed, though, was its ability to transmit through aqueous environments, enabling deeper tissue penetration.

Cellular Energy and Neurological Benefits

Additional research indicated infrared affected cellular mitochondria. Mitochondria produce ATP for cell function, generating energy for them to function. “All human cells contain mitochondria, particularly in neural cells,” notes the researcher, who prioritized neurological investigations. “Research confirms improved brain blood flow with phototherapy, which is always very good.”

Using 1070nm wavelength, cellular power plants create limited oxidative molecules. In low doses this substance, says Chazot, “stimulates so-called chaperone proteins which look after your mitochondria, preserve cell function and eliminate damaged proteins.”

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

Present Investigation Status and Expert Assessments

Upon examining current studies on light therapy for dementia, he says, several hundred individuals participated in various investigations, comprising his early research projects