Science · 9 min read ·
Mitragynine vs 7-Hydroxymitragynine: A Plain-English Guide to Kratom's Two Key Alkaloids
Kratom's effects come from two main alkaloids — and confusing them is at the root of most misconceptions about how kratom works. Here's the chemistry, the receptor pharmacology, and what the ratio on a COA actually tells you about a product.
Frequently Asked Questions
- What is mitragynine?
- Mitragynine is the most abundant alkaloid in kratom (Mitragyna speciosa), making up roughly 60–70% of the total alkaloid content in dried leaf. It's a partial mu-opioid receptor agonist with additional activity at adrenergic, serotonin, and other receptors. Mitragynine is responsible for most of kratom's everyday effects — at low doses it produces stimulation, focus, and mood elevation; at higher doses it shifts toward sedation and analgesia.
- What is 7-hydroxymitragynine?
- 7-hydroxymitragynine (7-OH) is a minor kratom alkaloid present in natural leaf at less than 0.1% by dry weight, and typically less than 2% of the total alkaloid fraction. It is much more potent at the mu-opioid receptor than mitragynine — published estimates put it at 10–13 times more potent than morphine on a per-molecule basis. In natural-leaf products, its small concentration is buffered by the much larger mitragynine fraction.
- Which alkaloid is responsible for kratom's effects?
- Both — but in different ways. At low and moderate doses of natural-leaf kratom, mitragynine is the dominant driver of effects: stimulation, focus, mood support, and at higher doses, relaxation and analgesia. 7-OH contributes to the analgesic and sedating end of the spectrum, but in natural leaf it is present in such small amounts that its activity is shaped by the mitragynine and other-alkaloid context. In synthetically concentrated 7-OH products, that context is removed, and the resulting effect profile is fundamentally different — closer to a synthetic opioid than to traditional kratom.
- How are mitragynine and 7-OH different chemically?
- Both are indole alkaloids with similar core structures. The 7-OH molecule has an additional hydroxyl (-OH) group at the 7 position, which dramatically changes how it binds at opioid receptors. The body also converts a small fraction of mitragynine into 7-OH metabolically, which means part of natural kratom's analgesic activity comes from in-vivo 7-OH conversion rather than from leaf 7-OH directly.
- Why does the mitragynine-to-7-OH ratio matter on a COA?
- Because the ratio tells you whether you're looking at natural kratom or a synthetic concentrate. Natural leaf and full-spectrum extracts show mitragynine as the dominant alkaloid, with 7-OH a small fraction (well under 2% of total alkaloids). A product where 7-OH is comparable to or higher than mitragynine is a synthetically concentrated product, banned under most modern KCPA legislation, and is a fundamentally different category of product even when sold under the kratom label.
- Are there other important kratom alkaloids?
- Yes. Speciogynine, paynantheine, and speciociliatine are next in abundance after mitragynine, and each has its own receptor activity that contributes to the full-spectrum effect of natural kratom. Mitraphylline, isomitraphylline, and rhynchophylline are also present in trace amounts. The total alkaloid count exceeds 40, which is part of why pharmacological characterization of natural kratom is more complex than the simple mitragynine + 7-OH story would suggest.
- The Science of Mitragynine: A Layperson's Guide to Kratom's Active Compound — Mitragynine is the alkaloid responsible for most of kratom's everyday effects — and the molecule that drives most consumer questions about kratom. Here's an accessible look at its discovery, chemical structure, receptor pharmacology, metabolism, and why concentration matters far more than 'how much kratom' you take.
- How 4 Leaf Herbals Sources Its Kratom: The Full Supply Chain, Top to Bottom — Most kratom on the US market changes hands through anonymous brokers between Indonesian growers and US retailers — which is why so many products test poorly, drift in alkaloid content, or carry inconsistent contamination profiles. We do things differently. Here is the full supply chain behind every product we ship: grower relationships, sourcing protocols, transport, lab testing, and packaging.
- Kratom Dosage Guide — Beginner doses and dose-by-weight chart for safe use.
- Lab Results Library — Every batch's third-party Certificate of Analysis.