You are Glowing, Literally — Human Bioluminescence

You are Glowing, Literally — Human Bioluminescence

30/10/2018 5

Bioluminescence is light produced by a living organism that is a result of a chemical metabolic reaction within the body of the organism.

Mention bioluminescence, and images of fireflies, jellyfish, bacteria, cave-dwelling glow-worms, and a variety of deep-sea creatures may come to mind.

Bioluminescence is not unusual in marine life — there are an estimated 1500 species of fish alone that luminesce. But did you know that humans emit light too?

In 2009, Japanese scientists discovered that the human body, especially the facial region, glimmers with light at an intensity that is a thousand times lower than what the human eye can detect.

The findings were published in PLoS One, in a paper titled, “Imaging of Ultraweak Spontaneous Photon Emission from Human Body Displaying Diurnal Rhythm.”

In the study, researchers stated that “the human body directly and rhythmically emits light” and that there is a diurnal change in photo emission. 

The researchers hypothesize that free radicals in energy metabolic processes are generating the photon emissions. When human cells respire, highly reactive free radicals are generated.

Scientists believe that these free radicals react with free floating lipids or proteins to generate excited molecule that can further react with fluorophores via energy transfer that leads to the emission of light.

Using an ultra-sensitive imaging system with a cryogenic charge-coupled device (CCD) camera, the team discovered that the photon emission intensity from the face was higher than the rest of the human body.

Within the facial region, the highest photon emission intensity was around the mouth and cheeks. The researchers observed that the intensity of the emissions also tend to follow a daily pattern where it starts out weak in the morning, and increases in intensity until it peaks in the early afternoon.

So the next time you are paid the compliment that you appear “glowing,” now you know for a fact that you are glowing all of the time — just in a manner that is undetectable to the human eye.

Copyright © 2018 Cami Rosso All rights reserved.


Kobayashi M; Kikuchi D; Okamura H. “Imaging of Ultraweak Spontaneous Photon Emission from Human Body Displaying Diurnal Rhythm.”  PLoS ONE. July 2009. 4(7): e6256. doi:10.1371/journal.pone.0006256.

Ocean Portal Team. “Bioluminescence.” Smithsonian Ocean. April 2018. Retrieved on 10-29-2018 from

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  • David Barclay

    Quite surprising to know that our body can actually glow.

  • Heather Gulliford

    Loved the conclusion of your article, really made me smile :D

  • Josh Thiel

    Surprising fact to be honest. Now I know why flies and other mosquitoes can see us in the dark even if they are far away.

  • Alice Price

    I think that scientists are completely capable to design a complete set of chromosomes with expressing bioluminescence genes in human.

  • Mike Williams


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