Photobiomodulation under the microscope.

Nature Video examines the science, commercial claims and open questions behind photobiomodulation.

What caught our attention

A 2025 umbrella review synthesised 15 meta-analyses covering 204 randomised clinical trials, more than 9,000 participants, 35 health endpoints and 15 disease conditions.

Where evidence looked stronger

The review reported moderate-certainty evidence for several outcomes, including pain reduction in burning mouth syndrome, disability in knee osteoarthritis, fatigue in fibromyalgia, hair density in androgenetic alopecia and cognitive function. Other outcomes were supported by lower or very-low-certainty evidence.

Why product claims need care

Photobiomodulation studies use different wavelengths, doses, devices, treatment schedules and target tissues. A positive result in one protocol cannot automatically validate every red-light panel, mask or wearable — or every claim made for them.

What could change the picture

More high-quality trials and better protocol standardisation would make it easier to identify which applications are robust, which doses matter and which apparent benefits are sensitive to study design or publication bias.

Why we are watching it

This is exactly where evidence mapping beats hype: identify the outcomes with meaningful support, separate them from speculative extrapolation, and then evaluate actual products against the parameters used in successful studies.