Kratom contains two primary active ingredients, mitragynine and 7-hydroxymitragynine, which act on the brain’s opioid receptors. These compounds are indole alkaloids native to the Southeast Asian plant, Mitragyna speciosa (kratom), traditionally used for its stimulant and analgesic properties. Mitragynine, the more abundant and well-known of the two, initially drew scientific interest for its role in kratom’s effects. However, kratom testing and research have unveiled that 7-hydroxymitragynine, although present in smaller quantities, is crucial to kratom’s mood-boosting potential.

7-hydroxymitragynine’s potent opioid receptor action is a focal point for understanding kratom’s safety and therapeutic value.
What is 7-OH Mitragynine?

7-Hydroxymitragynine, also called 7-OH mitragynine or 7-OH, is an active metabolite of mitragynine, the kratom plant’s principal psychoactive alkaloid. This substance is critical in enhancing mitragynine’s effects by strongly activating mu-opioid receptors. Interestingly, preliminary studies indicate that 7-OH binds to these receptors with even greater power. Along with opioid receptors, 7-hydroxymitragynine affects dopamine, serotonin, and adrenergic receptors.

When the body metabolizes mitragynine, 7-OH mitragynine forms as an active metabolite. Specifically, mitragynine converts to 7-OH within the liver, facilitated by cytochrome P450 3A isoforms. This transformation significantly enhances 7-OH’s effectiveness as a stress reliever, making it substantially more potent than mitragynine despite being present in kratom leaves at lower concentrations. According to a Columbia University study, 7-hydroxymitragynine is responsible for most of kratom’s opioid-receptor-mediated effects.

Columbia University’s animal study further elucidated that while mitragynine makes up two-thirds of kratom’s total active content, it does not directly activate opioid receptors in a significant manner. In fact, 7-hydroxymitragynine was around fivefold more potent than oral mitragynine. Kratom’s pharmacological profile, therefore, is not solely dependent on the direct action of its alkaloids but also on their metabolism, which influences the overall effects.