I always think it sucks when people don't get any effects from kratom because I promise you EVERYONE can achieve a high from Mitrigynine.
I'm lucky enough to live in one of the very few locations where you can buy pure Mitrigynine pills.
Some family man in my area who also happens to be a chemist found a way to isolate pure Mitrigynine from kratom.
The "kratom" in these pills which at that point is just an extracted substance is a white crystalline powder.
Not ONE person that I have given only ONE pill to has not gotten high off their ass.
Two of them actually threw up from getting so high but they were opiate naive.
Somehow you can even get these pills at double strength and I used those to get off Fentanyl.
Believe me, I used to think kratom was a dud too, it never "worked" for me but I realized that I just needed to take ungodly amounts of regular kratom for it to work...like 5 tablespoons or more which is so disgusting.
So in conclusion, kratom and its alkaloids work for everyone unless you are somehow invincible/your opioid receptors literally don't work.
And yes, you can nod off this stuff but unless you're like me and the people in my area getting this shit for a bargain I've only seen sites online selling isolate for hundreds to thousands of dollars a gram and that shits not even as pure as this completely white crystalline powder.