Are you talking about photobiomodulation (PBM)? I’ve done some research into different devices. Two main types that promote healing: 650 nm and infrared 850 nm. There are others along similar wavelengths but these are the most common.
You also have to look at intensity. My friend bought a $50 cheap device from China, hoping to treat his PD, but the box specifically said for cosmetic treatment (wrinkles, age spots, skin surface treatment, etc), but nothing deep.
Problem is PD is due to inflammation in the brain, so you need intensity strong enough to penetrate deep into the brain. The only way is through the nostrils, so a nasal insert with the highest intensity.
Thirdly, you can’t do combos: treat with 660 nm red light and then switch to 850 nm infrared afterwards, but don’t do them both together. Apparently, mitochondria responsible for cellular healing gets confused when you do both at the same time.
Also, beware of over- or under-doing. 25-30 minutes of each light twice a day separated by at least eight hours and should be during or immediately after meals.
One other thing to keep in mind: red light needs to shine directly on the skin. With infrared, it will penetrate through clothing, but not red light.
I bought myself a PBM set device to treat my fibromyalgia. First day, didn’t feel any different, but 3rd day, wow, huge difference. Pain dropped from 7-9 down to 2-4. What’s more, due to lack of melatonin sleep hormone, I used to average 3-4 hours of sleep but the PBM increased my sleep quality so I could sleep through most of the night and average between 5-7 hours of sleep.
And yes, I do combine both PEMF and PBM together or separately depending on my needs, no problem at all. Studies suggest you can get better results this way, though I can’t say there is a noticeable difference for me, but nevertheless there’s no detriment either. Metaphorically, instead of single bullets, I attack my condition with all guns blazing!
One thing to keep in mind: this is not a quick fix. Everyone responds differently: for some it may take a few days to see a difference, other maybe several weeks. For me, I was fortunate to notice in just a few days, but on the other hand I still have good and bad days, just fewer bad days than before, plus less intense pain and faster recoveries.
Another detriment, two hours of PBM takes up a lot of time especially since therapy must center around meal times.
And lastly, shop for quality. When I was researching PBM, I found the range of quality can vary vastly. Look for something with 2-3 year warranty and see which part of the body it can target. Even in one company, depending on the device if they sell more than one, they can vary in quality.
I’m no expert, but because these devices can get pretty pricey so I’ve done some reading and shopped around thoroughly to ensure I was getting the right thing.
Hope this helps.