I can speak to this. I got Long Covid almost 3 years ago now. The bottom line is, it's not a magic bullet. I have spent double my life's savings on anything and everything that was purported to help, to no avail. I am now out of work. So, that's how 'effective' it is. Do I doubt that it helps? No. On a small level, I have no doubt that it helps the mitochondria increase ATP. Is it enough for me to function even remotely close to normal? No. Not at all. And that is with all the other things I was doing to support my mitochondria (supplements, etc). I purchased my red light devices just over a year ago. I admit that early on, I had some trouble being consistent, which is important. But it was not able to help me keep my job.

That all said, I was trying to follow the instructions of 20 minutes a day, about 5 or 6 days a week. Starting today, I found a 2019 study that shows mice seem to perfom best between 3 and 6 hours. I am now going to try to do it several hours a day. I have a huge panel as well as the VieLight headset. Many days I am too exhausted and fatigued to stand in front of the panel. But I am going to start using the transcranial VieLight headset several times a day to see how that goes. But again, I want to let everyone know that there is, without a doubt, no magic bullet--not for the vast majority of people, anyhow. If you have the money, by all means, get it. But I cannot tell you it will be the magic solution.