7-Hydroxymitragynine (7-OH)

A minor kratom alkaloid that is roughly thirteen times more potent than mitragynine at the mu-opioid receptor — present in trace amounts in raw leaf, generated in larger amounts when the body metabolises mitragynine.

Why it matters

In a typical kratom leaf, 7-hydroxymitragynine sits at well under 1% of total alkaloid content. Its pharmacological footprint is outsized: it binds the mu-opioid receptor as a full agonist with higher affinity than mitragynine itself, and animal studies position its analgesic potency in a range closer to morphine on a per-milligram basis than to its parent alkaloid. Several states have responded by capping the permitted 7-OH concentration in finished kratom products under their Kratom Consumer Protection Act frameworks.

In practice

Where 7-OH matters in practice is in concentrated extracts, tablets, and shots marketed as “potency-organised” kratom products. These can contain hundreds of times more 7-OH per serving than the same dose of leaf powder. From a harm-reduction view that is the meaningful product distinction: leaf and 7-OH products are not interchangeable, even when sold under the same brand.

Common confusion

Some marketing material implies 7-OH is the “active ingredient” of kratom. That overstates the case. In leaf at customary doses, mitragynine drives most of the experience because there is far more of it; 7-OH contributes incrementally and after metabolic conversion. The “active ingredient” framing applies more accurately to concentrated 7-OH products than to the dried leaf.

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