I realize this is going to apply to a small fraction of people, but there is an additional caution I would like to add about kratom. There are two compounds in kratom that work as mu-opioid receptor partial agonists. I think of it like a natural analog of buprenorphine. As such, try to avoid taking kratom with full opioid agonists.

Anecdotally, this became relevant one time in my experience. I saw someone undergo elective orthopedic surgery, and he was using large doses of kratom up to the day of surgery. 24 hours after the surgery, when the nerve block had worn off, his usage of oxycodone and hydromorphone skyrocketed due to uncontrolled pain. And even then, he looked like he was going through opioid withdrawal.

At that time, it was hypothesized that some of the kratom had been eliminated from his system to have him go into withdrawal, but enough remained to block the action of the regular opioid medication. The pain crisis period eventually passed, but man did he have a really bad time.