Kratom is derived from a tree which grows in SE Asia and is effective for pain control. The active ingredients produce an effect similar to an opioid, but is not an opioid. It is not a drug, though attempts have been made to restrict and control it.
I have used kratom for pain control from my thoracic scoliosis, and it works. It is not a mind altering anything, but rather a safe and effective alternative to dangerous and addictive pharmaceuticals.