(EDIT because I'm not allowed to make a new comment for some reason, this is a reply to the comment below)
Every person is different and you must take care of what you put in your body. I take kratom because it's a double whammy that reduces two problems - depression and migraine - to manageable levels, while having low potential for addiction. I have so far encountered no negative effects from taking it, only positives.
However, I would prefer _not_ to take it. I would prefer _not_ to have depression and migraines and not to need any drugs to maintain a normal lifestyle.
I work on this by maintaining a healthy diet, exercising regularly, sleeping well, meditation, and maybe I'll get there someday. In the meantime, kratom has increased my quality of life a lot over the past few years. This is not intended as a suggestion that anyone else should take it, just an anecdote about my experience.
Regarding constipation - I have heard this before, but never personally experienced it. I mix each dose (<1tps) with a full cup of water, which probably helps.
Also at minimum constipation is a massive symptom