Mitragynine & 7-Hydroxymitragynine - The Alkaloids Behind Kratom

Every conversation about kratom eventually comes back to alkaloids. Vein color reflects alkaloid development, harvest timing targets alkaloid composition and drying method shapes alkaloid preservation. With Lab testing verifing alkaloid content and contaminants. The entire framework through which kratom is understood from strain selection to quality evaluation is built on the alkaloid profile of the Mitragyna speciosa leaf.
Yet most kratom users have only a surface level understanding of what those alkaloids actually are, how they differ from one another, and what their concentrations in the powder actually mean. This guide addresses that gap breaking down the science of kratom's primary alkaloids in plain language so you can make more informed decisions about what you're putting in your routine and what the numbers on a lab report actually tell you. There is still a lot to learn about the alkaloids in the Mitragyna Speciosa plant and I personally believe that in the future scientists will be able to prove more of kratom's unknown benefits that users notice are scientifically true and they may be able to use these alkaloids to synthesize new products. 

What Are Alkaloids?
Alkaloids are a class of naturally occurring organic compounds found throughout the plant kingdom. They are nitrogen containing molecules produced by plants as part of their natural chemistry often as a defense mechanism against insects and herbivores, though their biological roles vary widely across species.
Alkaloids are responsible for the characteristic botanical effects of many of the world's most widely used plants. Caffeine in coffee and tea is an alkaloid. Nicotine in tobacco is an alkaloid. Morphine and codeine in the opium poppy are alkaloids. Quinine the anti-malarial compound from cinchona bark is an alkaloid class that varies enormously. What alkaloids share is their chemical structure and the fact that they are biologically active in ways that are measurable and documentable.
The Mitragyna speciosa tree contains over 40 identified alkaloids. The two most present in the highest concentrations also have been the subject of the most scientific research: mitragynine and 7-hydroxymitragynine.

Mitragynine The Primary Alkaloid
Mitragynine is the most abundant alkaloid in Mitragyna speciosa leaf by a significant margin. In most kratom powders mitragynine represents the dominant alkaloid by weight accounting for the majority of total alkaloid content and the largest proportion of what a third-party lab measures and reports on a Certificate of Analysis.
Chemically mitragynine is classified as an indole alkaloid with a structural category it shares with a number of other plant-derived alkaloids including those found in various fungi and botanical species. Its molecular structure was first fully characterized by scientists in the 1960s and it has been the subject of ongoing pharmacological research since then.
Mitragynine is unique among alkaloids in several ways that make it scientifically interesting. Its molecular structure is complex enough that synthesizing it in a laboratory setting is considerably more difficult than extracting it from the plant which means virtually all mitragynine in circulation comes from actual Mitragyna speciosa leaf rather than synthetic production. This is one of the reasons why the plant itself remains the irreplaceable source of the compound and why supply chain integrity matters so much in the kratom market.
In third party lab testing mitragynine concentration is reported as a percentage of total powder weight typically ranging from around 1% to 1.7% or higher in quality leaf powder depending on the strain, vein color, harvest conditions, and processing method. A COA reporting 1.2% mitragynine on a 100 gram bag means approximately 1.2 grams of mitragynine is present in that 100 grams of powder. Understanding this relationship helps users interpret lab results in practical terms.
The Secondary Alkaloid 7-hydroxymitragynine is present in significantly lower concentrations than mitragynine in typical kratom powder usually accounting for less than 0.1% of total powder weight in most samples but it has attracted substantial scientific interest due to its potency relative to its concentration.
Chemically 7-hydroxymitragynine is a metabolite of mitragynine meaning it is produced through the natural oxidation and transformation of mitragynine molecules, both within the plant itself during leaf maturation and within the body after consumption. The prefix "7-hydroxy" indicates a specific molecular modification at the 7-position of the mitragynine structure is a small chemical change that produces meaningful differences in how the molecule interacts with biological systems.
Research into 7-hydroxymitragynine has found it to be considerably more potent by weight than mitragynine in laboratory studies meaning smaller quantities produce more pronounced biological activity than equivalent amounts of the primary alkaloid. This potency differential has made 7-hydroxymitragynine one of the most studied compounds in kratom research and a key focus of ongoing scientific investigation into the plant's pharmacology.
It is important to note that the scientific research on both mitragynine and 7-hydroxymitragynine is still developing. Much of the existing research has been conducted in laboratory or animal models rather than comprehensive human clinical trials. The FDA has not evaluated or approved any kratom product for any medical use and no therapeutic claims can be made about either alkaloid or the plants that contain them.

How Alkaloid Concentrations Vary Between Vein Colors
One of the most practically useful pieces of information for kratom users is understanding how alkaloid concentrations particularly the mitragynine to 7-hydroxymitragynine ratio vary across vein colors and how those variations connect to the botanical character the community documents for each category.

White vein kratom is harvested at the earliest stage of leaf maturity and it tends to carry the highest mitragynine concentrations relative to 7-hydroxymitragynine of the three primary vein colors. The early harvest timing captures the leaf's alkaloid profile before the natural oxidation processes that convert mitragynine to 7-hydroxymitragynine have had time to proceed significantly. This ratio is consistent with the community's documentation of white vein as the most characteristically distinct daytime botanical profile.

Green vein kratom is harvested at peak leaf maturity shows a balanced alkaloid ratio reflecting the midpoint of the leaf's natural alkaloid development. Mitragynine remains the dominant alkaloid but the profile shows more development than white vein material. This more balanced alkaloid composition is consistent with the community's extensive documentation of green vein as the most versatile and broadly applicable botanical category.

Red vein kratom is harvested at full leaf maturity shows the most developed alkaloid profile of the three primary categories. Full leaf maturity allows the natural processes that produce 7-hydroxymitragynine from mitragynine to proceed most completely producing a higher 7-hydroxymitragynine to mitragynine ratio than white or green vein material. This alkaloid development pattern is consistent with the community's documentation of red vein as producing the most grounding and settling botanical character of the primary three categories.

Gold and yellow vein are produced through extended fermentation or sun-drying of green or white vein leaves show alkaloid profiles that reflect the transformation that occurs during extended processing. The curing process allows continued alkaloid development and conversion beyond what the standard drying process. Which contributes to the smoother, more nuanced botanical character documented for both specialty categories.

The Over 40 Other Alkaloids
While mitragynine and 7-hydroxymitragynine receive the most scientific attention they don't tell the complete story of kratom's alkaloid profile. Mitragyna speciosa contains over 40 identified alkaloids including speciociliatine, speciogynine, paynantheine, mitraphylline, and corynantheidine among others.
These secondary alkaloids are present in lower concentrations than mitragynine but are not without biological significance. The kratom community has long discussed what some users describe as the "entourage effect" the idea that the full alkaloid profile of the plant produces a more complete botanical experience than any single isolated alkaloid could replicate. While this concept has not been formally validated in clinical research it reflects the community's collective observation that whole plant kratom powder behaves differently than isolated mitragynine and that the secondary alkaloid constellation may play a meaningful role in that difference.
This is one of the reasons why kratom extracts which concentrate specific alkaloids at the expense of others are frequently documented by experienced users as producing a qualitatively different botanical experience than whole leaf powder, even when mitragynine concentrations are comparable.

What Lab Testing Actually Measures
Third-party Certificates of Analysis for kratom products typically report alkaloid content in one of two formats as a percentage of total powder weight or as milligrams per gram of powder. Both convey the same information in different units and can be converted directly.
A COA reporting 1.4% mitragynine means 1.4 grams of mitragynine per 100 grams of powder or 14 milligrams per gram. A COA reporting 0.04% 7-hydroxymitragynine means 0.4 milligrams per gram.

What to look for on a COA:
Mitragynine percentage - Quality leaf powder from reputable sources typically reports mitragynine concentrations in the range of 1.0% to 1.7% or higher. Concentrations significantly below 1.0% may indicate older material, improper storage, or substandard source leaf. Concentrations reported at unusually high levels warrant scrutiny as extremely high mitragynine percentages can in some cases indicate concentrate blending rather than pure leaf powder.

7-Hydroxymitragynine percentage will mist likely be present but in small amounts. Concentrations significantly higher than 0.1% in a product labeled as plain leaf powder warrant attention as very high 7-hydroxymitragynine levels can indicate that extract material has been added to the powder, which would affect serving size calibration and is not typical of pure leaf powder products.
Heavy metals panel include Lead, arsenic, cadmium, and mercury which should all be tested and reported below established safety thresholds. Mitragyna speciosa is a bioaccumulator meaning it draws minerals from the soil into its tissues which makes heavy metals testing particularly important for kratom products sourced from regions with variable soil contamination.

Microbial panel - Salmonella, E. coli, total yeast and mold, and total aerobic plate count should all be tested and reported within acceptable ranges. Kratom powder is a botanical food adjacent product that can harbor microbial contamination if processing and storage conditions are inadequate.
All Tropical Hill Botanicals products are tested for all of the above before they ship. COAs are publicly posted on every product page openly accessible to anyone who wants to verify what they're ordering before it arrives.
For a full guide on how to read a Certificate of Analysis see our How to Read a Kratom COA Guide.
Why Alkaloid Content Varies Between Batches
Even from the same strain, same vendor, and same growing region the alkaloid concentrations vary between harvest batches. This is normal and expected in any botanical product harvested from living plants in variable environmental conditions.

Factors that influence alkaloid levels from batch to batch

Seasonal growing conditions - Wet season vs dry season harvests produce leaf with different mineral uptake profiles and alkaloid concentrations as discussed in our Kratom Aroma Guide.

Leaf maturity precision - Small variations in harvest timing produce small but measurable differences in alkaloid ratios. A red vein batch harvested at peak maturity versus one picked slightly early will show different 7-hydroxymitragynine to mitragynine ratios even from the same trees.

Drying conditions - Temperature, UV exposure, and drying duration all influence alkaloid preservation during processing. Rushed drying at excessive heat can degrade alkaloid content measurably.

Storage conditions - Time and environmental exposure between processing and consumption affect alkaloid stability. Properly stored fresh material consistently delivers higher alkaloid concentrations than older or improperly stored powder.
This is why third-party testing on a per-batch basis rather than a one time historical test applied to all future inventory is the meaningful quality standard. A COA from two years ago tells you very little about what's in the bag you're ordering today.

Frequently Asked Questions
What is mitragynine?
Mitragynine is the most abundant alkaloid in Mitragyna speciosa leaf and the primary active compound in kratom powder. It is an indole alkaloid unique to the Mitragyna speciosa plant not found in meaningful concentrations in any other botanical species. Mitragynine is present in quality kratom powder at concentrations typically ranging from 1.0% to 1.7% or higher of total powder weight and is the compound measured and reported on third-party Certificates of Analysis as the primary quality indicator.

What is 7-hydroxymitragynine?
7-hydroxymitragynine is a secondary alkaloid in Mitragyna speciosa present in significantly lower concentrations than mitragynine typically less than 0.1% of total powder weight in standard leaf powder. It is a naturally occurring metabolite of mitragynine produced through oxidation during leaf maturation and has attracted substantial scientific research interest due to its potency relative to its concentration. It is reported alongside mitragynine on third-party COAs as a secondary alkaloid measure.
How many alkaloids does kratom contain?
Mitragyna speciosa leaf contains over 40 identified alkaloids. Mitragynine and 7-hydroxymitragynine are the most abundant and most studied but a constellation of secondary alkaloids including speciociliatine, speciogynine, paynantheine, and mitraphylline are also present and may contribute to the overall botanical character of the plant in ways that isolated alkaloid research does not fully capture.
What mitragynine percentage is good kratom?
Quality leaf powder from reputable sources typically reports mitragynine concentrations in the range of 1.0% to 1.7% or higher on third-party COAs. Concentrations significantly below 1.0% may indicate aged material, improper storage, or substandard source leaf. Concentrations reported at unusually high levels warrant scrutiny as they can in some cases indicate concentrate blending rather than pure leaf powder. Always verify alkaloid content through a current third-party COA rather than relying on vendor claims alone.
Does vein color affect alkaloid concentration?
Yes and meaningfully so. White vein kratom harvested at early leaf maturity shows the highest mitragynine to 7-hydroxymitragynine ratios of the primary three vein colors. Red vein harvested at full maturity shows more developed 7-hydroxymitragynine concentrations as the natural alkaloid conversion process has had more time to proceed. Green vein sits between the two reflecting peak maturity alkaloid development. Gold and yellow vein show profiles further transformed by extended post-harvest processing.
Is 7-hydroxymitragynine dangerous?
7-hydroxymitragynine is usually present in trace amounts in standard kratom leaf powder with less than 0.1% of total powder weight being its makeup. The scientific research on its pharmacology is still developing and the FDA has not evaluated or approved any kratom product for medical use. If you have specific health concerns about kratom alkaloids or their interaction with medications or conditions consult a licensed healthcare professional before use.

How many alkaloids does kratom contain?
Mitragyna speciosa leaf contains over 40 identified alkaloids. Mitragynine and 7-hydroxymitragynine are the most abundant and most studied but a constellation of secondary alkaloids including speciociliatine, speciogynine, paynantheine, and mitraphylline are also present and may contribute to the overall botanical character of the plant in ways that isolated alkaloid research does not fully capture.

What mitragynine percentage is good kratom?
Quality leaf powder from reputable sources typically reports mitragynine concentrations in the range of 1.0% to 1.7% or higher on third-party COAs. Concentrations significantly below 1.0% may indicate aged material, improper storage, or substandard source leaf. Concentrations reported at unusually high levels warrant scrutiny as they can in some cases indicate concentrate blending rather than pure leaf powder. Always verify alkaloid content through a current third-party COA rather than relying on vendor claims alone.

Does vein color affect alkaloid concentration?
Yes meaningfully so, get this:  White vein kratom harvested at early leaf maturity shows the highest mitragynine to 7-hydroxymitragynine ratios of the primary three vein colors. Red vein harvested at full maturity shows more developed 7-hydroxymitragynine concentrations as the natural alkaloid conversion process has had more time to proceed. Green vein sits between the two reflecting peak maturity alkaloid development. Gold and yellow vein show profiles further transformed by extended post-harvest processing.

Is 7-hydroxymitragynine dangerous?
7-hydroxymitragynine is present in very small concentrations in standard kratom leaf powder which is typically less than 0.1% of total powder weight. The scientific research on its pharmacology is still developing and the FDA has not evaluated or approved any kratom product for medical use. If you have specific health concerns about kratom alkaloids or their interaction with medications or conditions consult a licensed healthcare professional before use.

Why do kratom alkaloid levels vary between batches?
Batch to batch alkaloid variation is normal in any botanical product harvested from living plants in changing environmental conditions. Seasonal growing variation, slight differences in harvest timing, drying conditions, and storage all influence the final alkaloid concentration in any given batch. This is why per-batch third-party testing rather than a one-time historical test is the meaningful quality standard. A COA from two years ago tells you very little about what's in the bag you're ordering today.
What is the difference between kratom powder and kratom extract in terms of alkaloids?
Kratom extracts concentrate specific alkaloids typically mitragynine and sometimes 7-hydroxymitragynine at the expense of the secondary alkaloid constellation present in whole leaf powder. This produces a product with higher concentrations of the primary alkaloids per gram but without the full range of secondary alkaloids the plant naturally contains. Many experienced users document qualitatively different botanical experiences between extract and whole leaf powder even when mitragynine concentrations are comparable. It's consistent with the community's observation that the full alkaloid profile may produce a more complete botanical experience than concentrated isolates.

Can I verify alkaloid content before buying kratom?   Yes and you should because reputable vendors publish current third-party Certificates of Analysis for every product that report mitragynine and 7-hydroxymitragynine concentrations along with heavy metals and microbial safety results. All Tropical Hill Botanicals products have publicly posted COAs on every product page accessible to anyone before purchase without requiring a request or account. If a vendor cannot provide a current per-batch COA that is itself meaningful quality information.

Does kratom lose alkaloid potency over time?  Yes the alkaloids degrade over time through oxidation and exposure to light, heat, and humidity. The rate of degradation depends significantly on storage conditions. Properly stored kratom in airtight containers away from light and heat maintains alkaloid integrity considerably longer than powder stored in ambient conditions. The aromatic diminishment discussed in our Kratom Aroma Guide frequently parallels alkaloid degradation. Flat or chalky aroma is often an indicator that alkaloid potency has declined alongside the volatile aromatic compounds that share similar environmental sensitivities