When I say the sun is the best source, I’m not just saying that because it’s zero cost. That’s also true, but it has the greatest power to positively impact your mitochondria. There’s also evidence that it can improve testosterone and estrogen levels in both men and women.
Every time I talk about this, people say, “There’s no sun here.” Unless you live in a cave, there’s sun. But it is true that on overcast days, long-wavelength light is filtered out.
It’s still important to get sunlight in your eyes on those days for circadian rhythm regulation. On overcast days, as well as when you need more mitochondrial stimulation, red light devices can be useful. Most of them emit both red light and infrared or near-infrared light.
Full disclosure: Joovv is a sponsor of tge Huberman Lab podcast because, to my knowledge, those are the only medical-grade red and infrared light devices that are commercially available.
One of the really cool things about long-wavelength light, regardless of the source, is that it can penetrate deep into the skin and scatter as much as 8 cm.
In this post, I talk about how to avoid excess UV exposure while still getting plenty of long-wavelength light from the sun.
I did an entire episode about light—Episode 4 of the Huberman Lab podcast. The episode out now with Roger Seheult, M.D., also covers this in detail, including how red light can improve blood glucose regulation.
The last point is that photobiomodulation is now considered a core component of dermatology and other fields of medicine.