I've used it to lessen my use of Adderall for narcolepsy and it's been a lifesaver.

I mixed about 2 tsp into water in the afternoon when I'm dragging, rather than taking more prescription stimulant. I use it between 1-3 times a week for at least 5 years, with several month long breaks in this time.

I think the weird derivative chemicals from it are probably dangerous, but I personally haven't experienced any problems with routine kratom use. I only use the powdered plant form I order from a reputable source, not the gas station drinks with synthetic versions.