MGM-15 and MGM-16 are semi-synthetic compounds derived from kratom alkaloids, named alongside mitragynine pseudoindoxyl in FR Doc 2026-13581, one of the two DEA scheduling notices published in the Federal Register on 2026-07-06. As described in that notice, MGM-15 is dihydro-7-hydroxymitragynine and MGM-16 is 9-fluoro-dihydro-7-hydroxymitragynine. Unlike the parallel 7-OH notice, this one carries no threshold — any detectable amount is captured, along with isomers, esters, ethers and salts.
That no-threshold structure is the whole story, and it is more restrictive than most people realise on a first read. Here is what these compounds are and why the drafting choice matters.
Quick Reference
| Name | Chemical identity | Threshold |
| MGM-15 | Dihydro-7-hydroxymitragynine | None — any detectable amount |
| MGM-16 | 9-fluoro-dihydro-7-hydroxymitragynine | None — any detectable amount |
| Mitragynine pseudoindoxyl | Rearranged oxidation product of mitragynine | None — any detectable amount |
| 7-OH (separate notice, FR Doc 2026-13580) | 7-hydroxymitragynine | 0.050% w/w, or 1.00 mg per article |
Where the Names Come From
"MGM" is a laboratory shorthand rather than a trade name or a botanical term. The numbers are sequence identifiers from research on mitragynine analogues, not a measure of strength or a rank of any kind. MGM-16 is not "one better" than MGM-15; they are simply two entries in a series.
Structurally, both are built from the 7-hydroxymitragynine scaffold. MGM-15 is its dihydro form — the "dihydro" prefix indicates the addition of hydrogen across a double bond in the parent structure. MGM-16 takes that same dihydro framework and substitutes a fluorine atom at the 9-position.
The fluorine is the detail worth pausing on. Fluorine substitution at a specific ring position is not something a plant does. Mitragyna speciosa does not biosynthesise fluorinated alkaloids, and neither does any other botanical you will encounter in this category. A 9-fluoro compound is the product of deliberate synthetic chemistry in a laboratory, full stop. When a compound like that turns up in a consumer product, it did not get there by growing.
That distinction is why the regulatory treatment diverges so sharply from the 7-OH action. 7-hydroxymitragynine occurs naturally in kratom leaf at trace levels, which is exactly why DEA had to build a threshold around it — a flat prohibition would have swept in every leaf ever grown. There is no equivalent problem with MGM-16. Nothing occurs naturally, so nothing needs to be carved out.
Why "No Threshold" Is Stricter Than a Threshold
A threshold listing sets a line and asks whether a product sits above or below it. The 7-OH notice does this with two prongs: 0.050% by weight, or 1.00 milligram per article, whichever trips first. A product can be tested, measured against those numbers, and — at least in principle — shown to fall outside the scope. We worked through that arithmetic in our breakdown of the 0.050% and 1.00 mg thresholds.
A no-threshold listing removes that possibility. There is no number to sit below. The standard is any detectable amount, which means the effective legal line is not set by the notice at all — it is set by the sensitivity of whatever analytical method is applied.
Follow that through and the consequences stack up:
- The line moves as instruments improve. A method with a limit of detection at 1 part per million and a method with a limit of detection at 10 parts per billion will disagree about the same sample. Both are "correct." Only one finds the compound.
- There is no dilution strategy. Under a percentage threshold, blending a small amount of material into a larger mass can bring the concentration down. Under a no-threshold standard, dilution just makes a positive harder to find — it does not make the article compliant.
- Trace contamination counts. Residue on shared equipment, carryover in a production line, or cross-contact in a co-packing facility can put a detectable amount into a product that was never intended to contain any.
- "Below the limit of quantitation" is not the same as absent. A result reported as detected-but-not-quantifiable is still a detection.
The scope language extends further still. The listing reaches isomers, esters, ethers and salts of the named substances. That is standard controlled-substances drafting and it is there to prevent the obvious workaround of shipping a salt form or a close structural variant and arguing it is a different molecule.
Why a 7-OH-Only Panel Cannot Clear a Product
This is the part that matters most for anyone reading a certificate of analysis, and it is where a lot of marketing in this category quietly falls apart.
Analytical panels test for what they are configured to test for. An LC-MS/MS method targets specific compounds using specific mass transitions, and it needs a certified reference standard for each analyte to identify and quantify it. A panel built around 7-OH and the common kratom alkaloids will report on those compounds and be silent about everything else. Silence is not a negative result.
So a certificate showing non-detect for 7-hydroxymitragynine and mitragynine tells you something real about 7-OH and mitragynine. It tells you nothing at all about MGM-15, MGM-16 or mitragynine pseudoindoxyl, because those compounds were never in the method. Because their listing has no threshold, a product could contain an amount far too small to matter under the 7-OH standard and still be fully captured under FR Doc 2026-13581.
We will be direct about our own position here, because this is exactly the kind of gap the category papers over. Botanical Blends is a distributor and retailer — we carry other companies' brands and we do not manufacture, formulate or blend anything. What any given product contains is described by the brand on its own product listing, not by us. The supplier certificates we hold report non-detect for 7-hydroxymitragynine and mitragynine, which is the basis for the no kratom, no mitragynine, no 7-OH framing we use. We publish those documents on our COA page so you can check them yourself.
Those panels do not include MGM-15, MGM-16, mitragynine pseudoindoxyl or corynoxine B. So we do not tell you the products we carry are free of them, and we do not claim they are clear of "all scheduled compounds," because our paperwork does not support those sentences. Anyone in this market who does claim it should be asked, politely and specifically, which analyte list their lab ran. If the four compounds are not on it, the claim is not backed by the document.
How to Read a COA With This in Mind
Three questions get you most of the way:
- What is the analyte list? Not the headline, not the summary box — the actual itemised list of compounds tested. If a compound is not named there, it was not tested for.
- What are the limits of detection and quantitation? Under a no-threshold standard these numbers define the practical meaning of "non-detect." A method with a high LOD produces reassuring-looking reports and finds less.
- Who ran it, and is the batch identified? A certificate that does not tie to a specific lot number cannot be matched to the unit in your hand. Our longer treatment is at how to read a certificate of analysis.
What This Means If You Are Buying
The honest summary is that a no-threshold listing raises the evidentiary bar for everyone selling in this space, and most sellers have not raised their testing to match. The gap between "lab tested" as a marketing phrase and a published panel that names the specific compounds at issue is where the entire risk sits.
Cat's Claw (Uncaria tomentosa) is a different plant from kratom (Mitragyna speciosa), from a different genus, and is not named in either DEA notice. That is a fact about the scope of the filings. It is not, by itself, a statement about the contents of any specific finished product on any specific shelf — which is why the analyte list on the certificate remains the document that matters. Background on the botanical is at what Cat's Claw is, you can see what we carry in the Cat's Claw collection, and the companion compound explainer is mitragynine pseudoindoxyl.
Frequently Asked Questions
Are MGM-15 and MGM-16 found in kratom leaf?
No. They are semi-synthetic compounds produced by chemical modification. MGM-16 in particular carries a fluorine substitution, and fluorinated alkaloids are not produced by plants. Their presence in a product indicates synthetic origin.
What does "no threshold" mean in practice?
It means there is no permitted quantity. Any detectable amount falls within the listing, together with isomers, esters, ethers and salts. The practical line is set by the sensitivity of the test method rather than by a number in the notice.
If a product tests non-detect for 7-OH, is it clear of MGM-15 and MGM-16?
No. Those are separate analytes requiring separate reference standards and separate mass transitions. A 7-OH panel does not look for them, and a test that does not look cannot clear.
Does the DEA action apply to Cat's Claw?
Uncaria tomentosa is not named in FR Doc 2026-13580 or FR Doc 2026-13581. It is a different plant from Mitragyna speciosa. State law operates independently of federal scheduling, so check the rules where you live.
When does the listing take effect?
On or after 2026-08-05, on the date the order publishes in the Federal Register. There is no grace period and no sell-through. The mechanism is explained in how DEA temporary scheduling works.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. For adults 21+. Legality depends on the specific formulation and applicable state law — check the rules where you live. Nothing here is legal advice.