Posted by King K
on October 27, 2026
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What is in kratom? Dozens of alkaloids, and the count depends on who is counting. DEA's Diversion Control Division says "At least 54 alkaloids have been isolated in kratom." FDA says "kratom contains over 50 alkaloids", and the European Union Drugs Agency (EUDA) counts "over 40 structurally related alkaloids". Mitragynine is usually the most abundant. The rest are minor alkaloids, each usually present in much smaller amounts. And some products sold beside kratom contain compounds made in a lab from mitragynine rather than found in the leaf. We sell kratom extracts, so this page also says what a certificate of analysis, ours included, leaves out.
Read this part first if you feel unwell right now. Stop, and do not take more. If someone is difficult to wake, is not breathing normally, is having a seizure, or is unresponsive, call 911.
National: Poison Control is 1-800-222-1222, around the clock, for a reaction that worries you; call with the product in your hand. The crisis lifeline is 988, by call or text. The federal treatment locator is findtreatment.gov.
Two things stated plainly. Kratom is not a treatment for opioid use disorder, and it is not a treatment for opioid or kratom withdrawal. The medicines with an evidence base behind them are buprenorphine, methadone and naltrexone. And we are a seller, not a clinic, so every clinical question raised on this page belongs with a clinician or one of the numbers above rather than with us.
Checked October 26, 2026.
What this page covers. Kratom's alkaloids, three lab-made compounds, vein color, and what a certificate of analysis lists. No effects, dosing, buying or legal advice. Who wrote it. King K, which sells liquid kratom extracts and energy shots; KING K PRIME extract tablets carry our name and have a product page on grhkratom.com. Our own certificates of analysis measure only a handful of alkaloids, four or five in the main alkaloid panel, so a certificate, ours included, is not a full inventory of what is in a product. Federal status, as of October 26, 2026. On October 14, 2026, DEA published a notice of intent (FR Doc 2026-20943) to temporarily place the concentrated minor alkaloid and mitragynine pseudoindoxyl (MGPI) in Schedule I above a specified threshold. It says the order "will be published in the Federal Register on or after November 13, 2026", and no such order had been published as of October 26, 2026. A separate DEA temporary order placed MGPI, MGM-15 and MGM-16 in Schedule I from August 26, 2026.
Next review January 26, 2027.
The short answer: what is in kratom
Kratom is Mitragyna speciosa, and what is in it comes in three layers.
The leaf's alkaloids. DEA: "Kratom's chemistry centers on a unique class of indole alkaloids." Mitragynine usually leads them, and paynantheine, speciogynine and speciociliatine follow at a distance.
Other plant compounds. The EUDA also lists "several flavonoids, terpenoid saponins, polyphenols, and various glycosides" among the compounds isolated from the tree.
Things beyond the leaf's natural alkaloid profile. One minor alkaloid sold at levels far above the leaf's, three compounds made in a lab, and contaminants such as microbes or heavy metals, which an alkaloid test does not look for.
How many alkaloids are in kratom? Why the counts differ
Agencies. DEA's Diversion Control Division, October 2025: "At least 54 alkaloids have been isolated in kratom." FDA's kratom page, current as of December 2, 2025: "kratom contains over 50 alkaloids". The EUDA: "over 40 structurally related alkaloids", from "various parts of the tree", not the leaves alone.
Papers. A 2016 paper in the Journal of the American Chemical Society reported "more than 20 unique indole alkaloids"; a 2020 paper by FDA scientists, "over forty"; a 2023 Thai study, "More than 25"; and two papers from 2020 and 2021, at least 54.
They count different things: one 2020 paper's 54 are alkaloids isolated from the plant over the last century, not what a single leaf holds. The honest answer is a range with names attached. Distrust any bare number, ours included.
A count says nothing about amounts. The FDA scientists wrote that "The mitragynine congeners account for roughly 85% of the total alkaloid concentration of kratom", and that the others each account for less than one percent.
Mitragynine: how much of the alkaloids, how much of the leaf
DEA calls mitragynine "the most abundant alkaloid- about 66% of total alkaloid content". A 2025 FDA report gives the same share and a second number: "less than 2% of dried leaf content by weight, although there are reports of regional and seasonal variability in the tree's alkaloid composition."
Watch the denominator. About 66 percent is a share of the alkaloids, less than 2 percent a share of the dried leaf, and a percentage on a certificate a share of that product.
Even the two-thirds moves. The 2023 Thai study, citing a 2004 review, puts mitragynine at about 66 percent of the crude alkaloid extract from Thai kratom but about 12 percent of that from Malaysian kratom.
In the leaf itself, a 2021 study of Malaysian leaves in the Journal of Natural Products measured 9.38 to 18.85 mg of mitragynine per gram of dried leaf, and found two samples where mitragynine fell below quantification and speciociliatine stood out; the authors read that as at least two chemotypes. A 2022 Thai study in Frontiers in Plant Science found 7.5 to 26.6 mg per gram across trees in four regions. The 2023 Thai study found 0.31 to 3.46 percent by weight across 611 samples from 13 provinces, and wrote that "the alkaloid content in kratom diverges based on seasonal and geographical origin".
Products vary too. A 2020 study of 53 US commercial products in Scientific Reports found mitragynine content "varied by fourfold", and "the variability in alkaloid content is in no way reflected in the product labeling."
The minor alkaloids, by name
After mitragynine, the names that recur in the papers we read are paynantheine, speciogynine and speciociliatine. A 2020 paper in the Journal of Natural Products lists speciociliatine, speciogynine and mitraciliatine as diastereoisomers of mitragynine, which is to say close chemical relatives.
Our page on what can cause a false positive for kratom shows why these sister compounds matter in testing.
Other names in the papers include corynantheidine, mitraciliatine, corynoxine, corynoxine B, mitraphylline, isorhynchophylline and speciofoline, whose levels split the 53 commercial products in the 2020 study into "high-speciofoline" and "low-speciofoline" chemotypes. Several table rows draw on a 2021 ACS Chemical Neuroscience study of one powder; one of its authors co-founded Sparian Inc. and is an inventor on mitragynine-analog patent applications, as the paper discloses.
What the lab work shows. Every receptor finding here comes from cells or animals, and they do not always agree: the 2016 paper found mitragynine a partial agonist at the human mu receptor in cells but an antagonist at the mouse one. The 2021 neuroscience team wrote that "these minor alkaloids are unlikely to play the majority role in the biological actions of kratom". None of this is a human effect, and we describe no effects here.
| Compound | How much (source, sample) | What studies report (design) |
|---|---|---|
| Mitragynine. | "about 66% of total alkaloid content" (DEA). About 12 percent of crude alkaloid extract from Malaysian kratom, per a 2004 review (Plants 2023). 9.38 to 18.85 mg/g of dried leaf, Malaysia (J Nat Prod 2021). 7.5 to 26.6 mg/g, Thailand (Front Plant Sci 2022). | Partial agonist at human mu, antagonist at mouse mu, in cells (JACS 2016). |
| Paynantheine and speciogynine. | Together "approximately 16% of the total alkaloid fraction" (J Nat Prod 2021, citing earlier work). | No measurable agonist activity at human opioid receptors, in cells (JACS 2016). |
| Speciociliatine. | "2-4% of the total alkaloid content" (J Nat Prod 2021, citing earlier work). | No measurable agonist activity, in cells (JACS 2016). Two datasets report human mu binding constants of 54.5 nM and 560 nM. |
| Mitraciliatine. | Under 0.02 percent of one powder's alkaloid extract (ACS Chem Neurosci 2021). | Mu partial agonist in cells and in mice by brain injection (ACS Chem Neurosci 2021). |
| Corynantheidine. | "About 1% of alkaloid extract" in some extracts, per literature cited by ACS Chem Neurosci 2021. | Mu partial agonist in cells and mice (ACS Chem Neurosci 2021). |
| Corynoxine and corynoxine B. | 0 to 0.42 and 0 to 0.17 mg/g of dried leaf, Malaysia (J Nat Prod 2021). | Corynoxine: tested in rats by injection (J Nat Prod 2021); full mu agonist in mice by brain injection (ACS Chem Neurosci 2021). |
| Mitraphylline. | Below quantification in every Malaysian sample (J Nat Prod 2021). | None located in the sources we read. |
| The concentrated minor alkaloid. | Under 2 percent of alkaloids, and typically no more than about 0.01 to 0.04 percent of dry weight (FDA). 0.03 to 0.15 mg/g of dried leaf, Malaysia (J Nat Prod 2021). | Least stable alkaloid studied in heated lab solutions (J Anal Toxicol 2020; solutions, not products). |
| MGPI. | Not established as a leaf alkaloid; trace questions still open (Justice Department). | Forms from the concentrated minor alkaloid in human plasma in a test tube (ACS Pharmacol Transl Sci 2020). |
| MGM-15 and MGM-16. | Made in a lab (DEA). Not reported in the leaf by any source we read. | DEA cites preclinical data from animal models. |
The concentrated minor alkaloid
One minor alkaloid draws more attention than the rest, because some products carry it far above leaf levels, and on this site we call it the concentrated minor alkaloid. In the leaf it is a trace. FDA says it "comprises less than 2% of the total alkaloid content in natural kratom leaves", and the 2025 FDA report says it typically "occurs in botanical kratom in amounts no more than ~.01-.04 percent by dry weight".
Where it comes from. The leading explanation is that it forms from mitragynine after harvest: the FDA report says it "may be a postharvest oxidative derivative of mitragynine", and the UN Office on Drugs and Crime says it is "formed during the drying process". The 2021 Malaysian study, which measured it in most of its leaf samples, reads that as support for reports that it "could be a postharvest artifact of mitragynine". Still, it is not a closed case. DEA adds that it "can be synthesized from mitragynine through a one-step chemical reaction", and that "the chemical structures of synthetic and naturally occurring 7-hydroxymitragynine are identical."
Concentrated is not natural. FDA: "While 7-OH occurs naturally in trace amounts in the plant kratom, the FDA's warning is for products containing 7-OH as an added ingredient or at enhanced levels, which can be dangerous." Its report adds that extracting it straight from plant material "would simply be unfeasible economically". DEA's October notice names extracts, which concerns sellers like us: "Evidence suggests that commercially available products, including extracts and synthetic formulations, contain a significantly higher concentration of 7-hydroxymitragynine than what is found in botanical M. speciosa."
Trace is not a safety finding. In the same notice DEA wrote that "neither HHS nor DEA has made a finding that these substances are safe to use at below-threshold levels."
It is also fragile in solution. In a 2020 stability study funded by the National Institute of Justice, it "was the most unstable alkaloid studied", with significant losses at 40 C and above over 8 hours. That is forensic solution chemistry, not product shelf life.
Made in a lab: MGPI, MGM-15 and MGM-16
DEA's temporary order of August 26, 2026, is plain: "Unlike the indole alkaloids mitragynine and 7-hydroxymitragynine, which are naturally occurring in the plant, mitragynine pseudoindoxyl, MGM-15, and MGM-16 are produced through synthetic modifications of purified mitragynine isolates or 7-hydroxymitragynine." That order placed all three in Schedule I from August 26, 2026.
MGPI is the one with open questions. The Justice Department's announcement of August 25, 2026 says: "The published scientific literature has not established MGPI as a naturally occurring kratom alkaloid. However, scientific and analytical questions remain about whether MGPI may be reported at incidental trace levels in some botanical products as a result of processing, storage or analytical conditions." In a 2020 test-tube study, the concentrated minor alkaloid turned into MGPI far more readily in human plasma than in mouse, rat, dog or monkey plasma, though the authors say the absolute conversion rate is unknown. Our explainer on pseudoindoxyl goes further.
MGM-15 and MGM-16 are plainly lab-made. DEA calls MGM-15 "a derivative of 7-hydroxymitragynine" and says "MGM-16 is synthetically manufactured for research purposes and is not approved for any clinical indication in the United States." No source we read reports either one in the leaf. Our MGM-15 explainer covers both.
A certificate finds them only if the lab looks: DEA notes that "such closely related compounds require specific method and instrumentation for accurate identification."
Does vein color change what is in it?
Kratom is sold under red, green and white names. The best evidence we found comes from living trees, not shelves. The 2023 Thai study, in the journal Plants, took 134 samples in one subdistrict, 56 percent from green-veined trees and 44 percent from red-veined ones, then 611 samples from 13 provinces, and measured mitragynine, paynantheine and speciogynine.
In the first collection, the comparisons "suggested that the production of the three alkaloids in each group was consistent in red- and green-veined kratom plants in each period." In the second: "Analysis of leaf vein color and alkaloid production indicated no difference between each collection group." One exception: in June to August 2021, mitragynine and paynantheine "were distributed in the green-veined population rather than the red-veined population". Season and geography did shift levels.
Mind the limits: Thai trees, three alkaloids, and the vein color of a living leaf, not a name on a retail bag. We found no peer-reviewed study comparing retail products labeled red, green or white. The fair reading is narrow, and it does not prove color names mean nothing.
What a certificate of analysis lists and leaves out
A certificate of analysis (COA) reports what one lab found in one sample when it looked for specific compounds. A lab can only quantify a compound it has a reference standard for, and the 2020 Journal of Natural Products paper noted that while "there are over 50 kratom alkaloids reported, only 13 are commercially available". So a typical certificate lists a handful of alkaloids. Some add lab-made derivatives, and some add metals and microbes.
Contaminants need their own tests. FDA "has warned the public when certain kratom products were contaminated with Salmonella and/or concerning levels of heavy metals." A 2020 study of eight products from shops in suburban Chicago found microbes in all but two, and concluded they were "contaminated with metals, such as Pb and Ni, as well as microbes". That is a small sample, as its authors say. A certificate with no metals, microbial, solvent or pesticide results is silent on all of them.
Reading the results. "ND" means not detected at that method's limit, which is not zero. Where a certificate also uses "ND", "<LOQ" means detected, but below the level the method can quantify. A printed total is the total of what was measured: on our certificates, "Total Mitragyna Alkaloids" adds up four or five alkaloids.
State limits measure different things, so name the state with every number.
| State | The alkaloid line, in the text's words | Status |
|---|---|---|
| Texas. | SB 497, Sec. 444.003 as enacted: a processor may not sell a product with "7-hydroxymitragynine in the alkaloid fraction that is greater than two percent of the overall alkaloid composition of the product", or with "any synthetic alkaloids". | Enacted in 2023; now Health and Safety Code chapter 445. |
| Arizona. | A.R.S. 36-795.02: the same two percent line, no "synthetic alkaloid", and a label stating "the amount of mitragynine and 7-hydroxymitragynine contained in the product". | In statute. |
| Utah. | Utah Code 4-45-102: "Pure leaf kratom" may contain no kratom extract, and the concentrated minor alkaloid at no level "greater than 0.4% of the total kratom alkaloid composition of the product". | Effective May 6, 2026. |
| Rhode Island. | R.I. Gen. Laws 21-28.12-3 bars "Greater than 0.5 mg 7-hydroxymitragynine per gram", more than one percent of total alkaloids, and metals or solvents over set limits. | Effective April 1, 2026. |
| Florida. | Emergency rule 2ER26-2, per its notice, adds the concentrated minor alkaloid to Schedule I above "1 milligram per gram (mg/g) for solid or powdered products" or "1 milligram per milliliter (mg/mL) for liquid products", or under 100 parts mitragynine to one. | Effective August 18, 2026. |
Our own certificates report a handful of alkaloids too, so bring the same questions to them.
The certificate linked from our King K Platinum page as of October 26, 2026, covers lot 09012026 (Cora Science, LLC, report date September 17, 2026). Its alkaloid panel measures four alkaloids. Its derivative panel, run on September 16, 2026, reports mitragynine pseudoindoxyl as "<LOQ (2.18) ug/g": detected, but below the level the method can quantify. The DEA order placing MGPI in Schedule I took effect on August 26, 2026. The certificate reports "467 mg/package" of mitragynine for that sample, where our product page says "500mg MIT". None of our certificates carries a heavy-metal, microbial, residual-solvent or pesticide panel, while our homepage says "We publish what is in every bottle". Our certificates do not support that sentence.
One older certificate belongs here too. KING K PRIME tablets, lot 02122026, issued February 20, 2026, measured the concentrated minor alkaloid at 0.102 percent by weight as received, about 1.02 mg per gram, a shade above the 1 milligram per gram line in the federal threshold proposal and in Florida's rule. The certificate's limit line reads "NMT 400 PPM", its dry-weight result "1086 ppm", and its verdict "FAIL"; the 0.102 percent and the 1086 ppm are one result on two bases. We have not confirmed whether any of that lot remains in circulation. What the numbers mean in law is for counsel, not this page.
What this means if you are reading a label
Our advice: read a label and its certificate as two partial answers, and ask both the same questions.
Which compounds? A mitragynine figure covers one alkaloid out of dozens, and a certificate covers only what it names.
Which sample? The lab that tests our products prints this on its certificates: "All test articles are analyzed as received and the results relate only to the specific sample of material or product analyzed." Match the lot number.
Which units? Share of alkaloids, share of weight, milligrams per gram, per milliliter or per package. Compare like with like.
Does it test for contaminants? Metals, microbes, solvents and pesticides need their own panels.
Does it test for MGPI, MGM-15 or MGM-16? DEA describes those as lab-made, not leaf alkaloids, and its temporary order placed them in Schedule I.
If you hold one of ours, ask us whether a certificate covers your lot. Health questions go to a clinician, or to Poison Control at 1-800-222-1222, not to us.
Kratom alkaloid questions
What is in kratom?
Dozens of alkaloids, plus other plant compounds. DEA says at least 54 alkaloids have been isolated in kratom, FDA says over 50 and the EU drugs agency says over 40. Mitragynine is usually the most abundant, and the rest are minor alkaloids, each typically present in much smaller amounts.
How many alkaloids are in kratom?
It depends on who is counting and what they count. Agencies say over 40 to at least 54, and papers from 2016 to 2023 say more than 20 to at least 54. Most are present in very small amounts.
What are kratom alkaloids?
They are the leaf's indole and oxindole alkaloids, led by mitragynine, then paynantheine, speciogynine and speciociliatine, with corynantheidine, corynoxine and the concentrated minor alkaloid among the minor ones. Their receptor findings come from cell and animal studies, not from people.
Are MGPI, MGM-15 and MGM-16 kratom alkaloids?
Not according to DEA, which describes all three as produced through synthetic modifications of purified mitragynine isolates or of the concentrated minor alkaloid; for MGPI, the Justice Department says trace questions remain. A DEA temporary order placed all three in Schedule I from August 26, 2026.
Does a certificate of analysis show everything in a kratom product?
No. It reports what one lab found in one sample when it looked for specific compounds. A typical certificate lists a handful of alkaloids, ours included, and one without contaminant panels says nothing about contaminants.
Disclaimer: this page summarizes publicly available material as of October 26, 2026, and links to primary sources. Receptor findings here come from cell, test-tube and animal studies, not people, and amounts describe only the samples tested. It is general information, not legal or medical advice. Statements about botanical products have not been evaluated by the Food and Drug Administration, and no product is intended to diagnose, treat, cure or prevent any disease.
