How does kratom work?

Kratom contains over 40 different alkaloids, of which the main active alkaloids include mitragynine and 7-hydroxymitragynine, and the latter is the more potent form. These alkaloids act as partial agonists of the mu-opioid and delta-opioid receptors and are thought to be responsible for kratom’s pain relieving and sedating effects. These effects have been shown to be reversed with an opioid antagonist in animal models and in some clinical case studies where respiratory depression was the main symptom.^[1] Mitragynine has also been shown to interact with adrenergic, serotonergic and dopamine receptors, but the exact impact in humans is not yet known.^{[2] [3]}