Here is an article from biohackersummit . Red light topic is about halfway through article.
Red light, near infra-red light (NIR) or low-lever laser therapy has been used to treat various conditions from pain and muscle aches to wound healing, skin conditions, osteoarthritis and even depression. These effects are usually local, but near-infrared light has also systemic effects via circulation of blood. You might want to read this super comprehensive article on red light and NIR by a Finnish medical student Vladimir Heiskanen He has been a key source of information for me regarding the healing effects of red light.
The basis for stimulating testosterone production by shooting red light and near-infra red light especially on your testicles lies on the mechanism how red (or infrared) wavelengths work inside the cell. The key is that they stimulate ATP production in Leydig cells thus increasing the energy available for the cells. This means more testosterone production.
There might be also other mechanisms, which are speculated in ”Red Light Man” site:
”Another potential mechanism involves a separate class of photoreceptive proteins, known as ‘opsin proteins’. The human testes are especially abundant with various of these highly specific photoreceptors including OPN3, which are ‘activated’, much like cytochrome, specifically by wavelengths of light. Stimulation of these testicular proteins by red light induces cellular responses that may ultimately lead to increased testosterone production, amongst other things, although research is still in the preliminary stages regarding these proteins and metabolic pathways. These type of photoreceptive proteins are also found in the eyes and also, interestingly, the brain.”(83)
I haven’t found any human studies on the subject, but according to a few studies done on rats the positive effects on testosterone production are enormous. For example a Korean study found out that low level laser therapy (LLLT) with wavelength of 670nm (which is in border of visible red light and infra-red light) 30 mins per day showed significant increase in serum testosterone by fourth day of the treatment without any harmful tissue penetration.(84) In that study, a wavelength of 808 nm didn’t have any effect on T production. Another study done with rams didn’t show any positive effects on T production with 808 nm wavelength.(85)
Still, that wavelength (800 nm+) might work on humans on the basis of other LLLT studies on different tissues (such as thyroid).
- Overall, red or infrared light from LED source is generally thought to be a safe therapeutic method
- Avoid heating the testicles, since the heat will destroy sperm cells and have a negative effect on the Leydig cells
- Avoid blue light and UV light exposure on testicles (blue light inhibits ATP production in mitochondria)