The scientific studies have been scrutinized, and they've also been made by industry asides. A major problem with the medical research field are companies promoting studies with small sample sizes, where they pay for the study and have influence on the publication, and thus we can't trust them.
You know how many dubious medical studies you can find online?
In the case of LLLT, there is also a complete lack of long-term studies, and a lack of an actual scientific mechanism.
Finally, from personal experience, I find the process tedious and inefficient. It's ~45 minutes a week lost. That is actually a very serious side effect.