Did you know that your body gives off light? The light is very weak, about 1,000 times too weak for our eyes to see.

In 2009, Japanese scientists used a special cold camera in a dark room. They took pictures of five healthy men. The light from their faces was strongest around 4 p.m. This light comes from chemical reactions in the body. It is not an aura.

Your body is glowing right now, but you cannot see it. Living things, including humans, give off extremely weak light called ultraweak photon emission. It is about 1,000 times too faint for the human eye, so only very sensitive cameras can record it.

In 2009, a Japanese team photographed five healthy men in complete darkness every three hours over three days. The glow followed a daily rhythm. It was weak in the morning and peaked around 4 p.m. It was also strongest on the cheeks.

The brightest areas did not match the warmest areas, so the light is not simply heat. Scientists believe it comes from chemical reactions involving reactive oxygen, which is produced during metabolism. It has nothing to do with so-called auras.

A glowing human body sounds mystical, but ultraweak photon emission is a measurable physical phenomenon. Its intensity is roughly a thousandth of what the eye can detect, so it must be captured with cooled, highly sensitive cameras. In 2009, Kobayashi and colleagues photographed five healthy men in their twenties in total darkness every three hours from 10 a.m. to 10 p.m. over three days.

Emission followed a diurnal rhythm, peaking around 4 p.m., when the cheeks released about 3,000 photons per square centimeter per second, roughly twice the morning level. Because the brightest regions did not coincide with the warmest ones, the light is not merely thermal radiation. The leading explanation is that reactive oxygen species generated by metabolism oxidize lipids and proteins, producing excited molecules that release faint light as they return to a stable state.

In 2025, researchers using even more sensitive cameras reported a marked difference between living and dead mice and increased emission from stressed plants, suggesting a possible non-invasive measure of biological condition. Camera noise, cosmetics and stray light easily distort the signals, and studies have used few subjects. Claims that the glow reveals personality or an "aura" have no scientific basis.