7-Hydroxymitragynine (Kratom)
7-Hydroxymitragynine is a minor kratom alkaloid and active metabolite of mitragynine that acts as a substantially more potent mu-opioid receptor agonist. Isolated, concentrated 7-OH products are an emerging and growing safety concern.
Evidence last reviewed: 02 Aug 2026
Not a routine supplement — not recommended for self-directed use.
Information here is educational only, not a recommendation to use. See our Safety page.
- •Anyone with a current or past opioid use disorder or other substance dependence history
- •Pregnant or breastfeeding individuals — opioid-like neonatal withdrawal has been reported following maternal kratom use
- •Anyone taking opioids, benzodiazepines, alcohol, or other CNS depressants — additive respiratory depression risk
- •Anyone with liver disease or a history of drug-induced liver injury
- •Anyone with cardiac arrhythmia, QT prolongation, or taking QT-prolonging medications
- •Anyone taking MAOIs, SSRIs, or SNRIs — kratom alkaloids affect monoaminergic pathways in addition to opioid receptors
- •Anyone under 18
- •Anyone in a jurisdiction where kratom or its alkaloids are restricted or banned — check local regulations before use
- •Anyone considering concentrated or isolated "7-OH" tablets, gummies, or extracts marketed as legal opioid alternatives — these carry substantially higher overdose and dependence risk than raw kratom leaf
Active metabolite of mitragynine and a substantially more potent mu-opioid receptor agonist. Isolating and concentrating 7-hydroxymitragynine (rather than consuming it at the low, naturally-occurring ratio found in raw kratom leaf) produces markedly higher opioid-receptor exposure per dose.
Evidence is from research or clinical settings — does not imply safety outside supervised contexts.
Evidence specific to 7-hydroxymitragynine is newer and smaller than for mitragynine/whole-leaf kratom, concentrated in pharmacology, postmortem toxicology, and 2024–2025 reviews tracking the emergence of isolated 7-OH products. Consistently identifies it as markedly higher-risk than raw kratom leaf.
Markedly greater mu-opioid receptor potency than mitragynineAnimal models · PharmacologyModerate
Identifies 7-hydroxymitragynine as considerably more potent at the mu-opioid receptor than its parent alkaloid mitragynine, and the key driver of analgesic (and overdose) risk.
Emergence of concentrated 7-OH-mitragynine products as a public-health concernNarrative review · Narrative reviewLow
Describes the shift from traditional whole-leaf kratom use to concentrated, isolated 7-hydroxymitragynine products (tablets, gummies, "7-OH" shots) and the associated rise in toxicity, dependence, and regulatory concern.
Human pharmacokinetics after oral kratom dosingHealthy adults, controlled dosing · Clinical pharmacokinetic studyModerate
Characterizes human plasma pharmacokinetics of both mitragynine and 7-hydroxymitragynine after single and multiple oral doses of encapsulated dried kratom leaf powder — the basis for exposure and dosing-risk assessment.
Postmortem detection in fatality casesPostmortem toxicology, 51 cases · Postmortem toxicology reviewLow
Both alkaloids were detected across a series of postmortem cases, most involving co-ingested substances — supports treating concentrated 7-OH-mitragynine with the same caution as other opioids in a poly-substance context.
Cardiotoxicity from concentrated Mitragyna speciosa extractCase report · Case reportLow
Case report of acute cardiotoxicity following use of a concentrated Mitragyna speciosa (kratom) extract product.
Forms & usage▾
Safety & trade-offs5▾
Substantially more potent opioid-receptor agonist than mitragynine
Concentrated/isolated products carry markedly higher overdose risk than raw kratom leaf
Dependence & withdrawal potential
Reported cardiotoxicity with concentrated extract use
Additive CNS/respiratory depression with opioids, benzodiazepines, alcohol
●High ●Moderate ● Low / note