7-Hydroxymitragynine vs Kratom

The pharmacology, in one paragraph

A kratom leaf contains 40+ alkaloids, dominated by mitragynine (~66% of total alkaloid content) with only trace 7-OH. When you ingest leaf, mitragynine is converted to 7-OH in vivo by CYP3A4 — and that conversion is the rate-limiting step for kratom’s opioid effect (Kruegel 2019). A concentrated 7-OH tablet skips that step. You are receiving the active opioid alkaloid directly, at a dose your liver did not have to manufacture from a much larger pool of parent compound. The receptor profile is also narrower: 7-OH binds mu with roughly 13× the affinity of morphine and 46× that of mitragynine (Kruegel 2016), and rats generalise it to morphine in drug-discrimination assays while mitragynine is not generalised (Obeng 2021).

Translated to the user experience: low-dose leaf kratom can feel stimulating (it is a coffee-family botanical), and the sedative opioid character only emerges as dose climbs and 7-OH accumulates. A concentrated 7-OH product produces opioid-typical sedation, analgesia, and euphoria from the start of the dose-response curve.

Why “stronger” is the wrong question

Per milligram of active alkaloid at the receptor, 7-OH is roughly 13× morphine and 46× mitragynine. But kratom leaf is dosed in grams of plant material that contain only milligrams of alkaloids, and the pharmacologically active alkaloid — 7-OH itself — is produced in small amounts by the liver from that pool. The honest framing is not “which is stronger” but “how much 7-OH reaches the receptor, and how fast.” Concentrated 7-OH wins on both.

Dependence and abuse-liability differences

Chronic kratom users develop a dose-dependent withdrawal syndrome paralleling opioid withdrawal (Singh 2014), and rats self-administer isolated 7-OH at rates comparable to morphine while ignoring isolated mitragynine (Hemby 2019). The clean read of those two findings: leaf kratom carries opioid-like dependence risk that builds over months of regular use; concentrated 7-OH should be expected to compress that timeline, because the rate-limiting conversion step is gone. Full timeline on the withdrawal page.

Legal differences

A growing number of US states allow natural kratom leaf while restricting concentrated or isolated 7-OH. Variants of the Kratom Consumer Protection Act adopted across multiple states cap 7-OH content at 2% of total alkaloids — a threshold designed to permit natural-leaf products while excluding the concentrated extract market. Specific state language and enforcement vary; check the state-by-state legal tracker for current status.