Kratom-Sirup im Vergleich zu Codein-Sirup

Kratom syrup and codeine syrup: why the comparison fails

Anyone looking for a comparison between a syrup made from Mitragyna speciosa and a codeine syrup is usually looking for one thing: are these two versions of the same idea? The honest answer is no — and the reasoning behind that answer is far more interesting than the comparison itself.

This article therefore does not drop the comparison; it takes it apart. Where do the two substances come from botanically, which chemical classes do they belong to, how are they metabolised in the body, what does German and EU law say about each of them, and what does the available research actually support? At the end there is a correction that also concerns the earlier version of this article.

Why codeine is used as a benchmark at all

The comparison does not originate in the laboratory but in language. Both substances are alkaloids, both come from plants, and both are filed in popular accounts under the umbrella term "opioid-like". For many readers, that is reason enough to line them up side by side.

In reality, "opioid-like" is a statement about receptor binding in a model system — not a statement about law, tolerability, comparability or interchangeability. Anyone who moves from one level to the other turns a laboratory observation into an everyday claim.

There is also a historical factor. Codeine has been established as a pharmaceutical substance for over a hundred years and is correspondingly familiar, whereas Mitragyna speciosa has only been a topic in Europe for a few decades. The familiar then serves as the yardstick for the unfamiliar — including where it does not fit.

Correction: codeine is not a synthetic opioid

An earlier version of this article stated that codeine was a synthetic opioid while Mitragyna speciosa came from a natural source. That is factually wrong, and the correction is the real heart of the subject.

Codeine is a morphinan alkaloid and occurs naturally in the opium poppy (Papaver somniferum) — biosynthetically it is formed in the plant via the benzylisoquinoline alkaloid pathway. Chemically, codeine is the 3-methyl ether of morphine. It is therefore an opiate, a naturally occurring constituent of the poppy, and precisely not a molecule designed at a drawing board.

Industrially, codeine is nevertheless rarely isolated from the poppy. It is usually produced semi-synthetically by methylation of morphine, because the natural content in the raw material is too low for that purpose. The starting material remains botanical; only the final step is chemical. The contrast "synthetic versus plant-based" therefore cannot describe the difference between the two substances — both are plant alkaloids.

Opiate, opioid, semi-synthesis: three terms that are regularly confused

Opiate: an alkaloid that occurs naturally in the opium poppy — morphine, codeine or thebaine, for example.
Opioid: an umbrella term for all substances that bind to opioid receptors, whether plant-derived, semi-synthetic or fully synthetic.
Semi-synthesis: chemical conversion of a plant-derived starting material — here the methylation of morphine to codeine.
Total synthesis: assembling a molecule from simple bulk chemicals without a plant precursor; that is exactly what does not apply to codeine.

Codeine is a prodrug — and the CYP2D6 polymorphism explains why that matters

Codeine itself binds only weakly to the µ-opioid receptor. The pharmacologically decisive step happens in the liver: the enzyme CYP2D6 removes the methyl group (O-demethylation) and turns codeine into morphine. In technical terms this makes codeine a prodrug — a substance that only becomes the actually active form through the body's own metabolism. Only a small fraction of an administered amount is converted along this route; the larger part follows other pathways such as glucuronidation.

The gene for CYP2D6 is strongly polymorphic in humans, meaning it exists in many variants. This produces roughly four groups: poor metabolisers with no functional enzyme, intermediate metabolisers, normal metabolisers and ultra-rapid metabolisers with multiplied enzyme activity. The frequency of these variants differs markedly between populations.

Why this polymorphism has medical consequences

In poor metabolisers, hardly any morphine is formed — the medicine largely fails to produce the expected effect. In ultra-rapid metabolisers, the same amount yields an above-average quantity of morphine, with a risk of respiratory depression. This is precisely why the European Medicines Agency has repeatedly restricted the use of codeine-containing medicines, among others in children and during breastfeeding.

This finding is instructive for two reasons. First, it shows that "plant origin" says nothing about risk: codeine is plant-derived and nevertheless strictly regulated. Second, it shows how much work is required to know such relationships at all — genotyping, clinical trials, pharmacovigilance systems. For mitragynine, no comparable body of data exists.

Mitragynine: a Corynanthe-type indole alkaloid from an entirely different plant family

Mitragyna speciosa is a tree in the madder family (Rubiaceae), which also includes the coffee plant, and is native to Southeast Asia. The opium poppy, by contrast, belongs to the poppy family (Papaveraceae). Two families, two biosynthetic pathways, two alkaloid families — there is no botanical or chemical kinship.

The main alkaloid mitragynine is a monoterpenoid indole alkaloid of the Corynanthe type. Its scaffold derives from the amino acid tryptophan plus a terpene unit — a completely different blueprint from codeine's morphinan skeleton. More than 40 alkaloids have been described in the plant; the mitragynine content of dried leaves lies, depending on origin, harvest time and processing, roughly between 0.5 and 2 percent, while the minor alkaloid 7-hydroxymitragynine is typically below 0.05 percent.

What has been observed in the laboratory — and what does not follow from it

In cell and animal models, mitragynine and 7-hydroxymitragynine bind to µ-opioid receptors; mitragynine is predominantly described there as a partial agonist, 7-hydroxymitragynine as considerably more potent in binding. Interactions with adrenergic and serotonergic systems have also been investigated. In metabolism, in vitro data indicate that mitragynine is processed among other routes via CYP3A4, with 7-hydroxymitragynine forming in the process.

All of these findings are preclinical. They come from isolated cells, membrane preparations or animal experiments. Receptor binding in cell culture says nothing about what happens in a human being: absorption, distribution, metabolism, excretion, interactions with other substances and the composition of a multi-component plant mixture change the picture fundamentally. Receptor binding is a measured value, not a statement about effects. How receptors work in the first place is explained in the article Receptors explained simply.

Two plants, two alkaloid families: the comparison at a glance

Feature	Codeine	Mitragynine
Chemical class	morphinan alkaloid (benzylisoquinoline biosynthesis)	monoterpenoid indole alkaloid, Corynanthe type
Botanical source	Papaver somniferum (Papaveraceae)	Mitragyna speciosa (Rubiaceae)
Production	usually semi-synthetic from morphine	extraction from leaf material
Metabolism	prodrug, converted to morphine via CYP2D6	per in vitro data among others via CYP3A4
Composition	pure substance with declared content	multi-component mixture, over 40 alkaloids
Narcotics law (Germany)	listed in Schedule III of the BtMG	not listed in any BtMG schedule
Medicinal status	authorised active substance, prescription only	not an authorised active substance
EU food status	not applicable (medicine)	not authorised as a food (novel food)
Evidence base	decades of clinical studies	largely preclinical, case reports, surveys

Why "natural" versus "synthetic" is not a safety argument

The earlier version of this article built its argument on the contrast "plant-based versus synthetic". That contrast does not exist here: both substances are plant alkaloids. With it, the conclusion usually drawn from it falls away as well.

The origin of a molecule says nothing about its potency, its risks or its tolerability. Nicotine, atropine, strychnine, coniine and morphine are all plant-derived. Conversely, ascorbic acid from a fermenter is the same molecule as ascorbic acid from fruit. What matters is structure, quantity, purity, accompanying substances and the context in which a substance appears — not whether a plant stood at the beginning.

A second point applies specifically to plant extracts: the content fluctuates. An authorised medicine contains a declared amount of pure substance per unit, tested against pharmacopoeial standards. A plant extract is a mixture whose composition depends on origin, harvest time, drying and processing. This too makes the two quantities incomparable. Why quality testing of plant material is necessary at all is covered in the article Heavy metals and pesticides in kratom.

And what about the syrup dosage form?

The word "syrup" describes only a preparation form: a viscous solution, usually based on sugar, glycerol or sorbitol. It says nothing about the contents. A cough syrup containing codeine is an authorised medicinal product with a declared active-substance content per millilitre, a package leaflet, batch testing and prescription-only status.

The fact that two products share the same outward form does not make their contents comparable — no more than two liquids in identical bottles necessarily contain the same thing. Kratoein's products are expressly not intended for consumption and are supplied as collector's and research items; they are neither medicines nor foods, and they stand in no alternative relationship to any medicinal product.

The legal situation, kept separate

Codeine

In Germany, codeine is prescription-only and listed in Schedule III of the Narcotics Act (BtMG), meaning it is both marketable and prescribable. Preparations below certain thresholds named in Schedule III are exempt from the narcotics-specific prescription requirement; they nevertheless remain prescription-only medicines. Supply, documentation and prescribing are therefore governed by a dense set of rules.

Mitragynine

Mitragynine is not listed in any schedule of the BtMG. The New Psychoactive Substances Act (NpSG) does not capture it either, because that law works with chemically defined substance groups to which indole alkaloids of this type do not belong. Why this system keeps producing gaps is discussed in the article The problem with the BtMG, NpSG and AMG.

Why "not in the BtMG" does not mean "freely sellable"

This is where most accounts stop — too early. The fact that a substance is not listed in the BtMG means only that narcotics law does not apply. Other areas of law apply independently of it:

Novel food: under Regulation (EU) 2015/2283, foods without significant consumption in the Union before May 1997 may only be placed on the market after authorisation. No such authorisation exists for Mitragyna speciosa. Details in the article Kratom and novel food.
Medicinal products law (AMG): if a medicinal purpose is attributed to a product, that alone can cause it to be classified as a medicine — with an authorisation requirement.
Food law (LFGB) and the Medicinal Advertising Act: both limit what may be said about a product; disease-related or health-related claims are not permitted. See the article Kratom and the Medicinal Advertising Act.
National divergence: the situation across the EU is not uniform; individual member states have enacted their own bans, others have not.

A substance can therefore sit outside narcotics law and outside marketability as a food at the same time. "Not listed in the BtMG" and "harmless" are two entirely different statements.

Documented risks — on both sides

Naming risks does not contradict public information; it is its core. For codeine as a pharmaceutical substance, the documented risks include respiratory depression, particularly in ultra-rapid CYP2D6 metabolisers and in children, pronounced constipation, sedation, nausea, as well as tolerance development and dependence with prolonged use. Interactions with other depressant substances are a risk factor in their own right.

For mitragynine, or rather for preparations from Mitragyna speciosa, the information does not come from authorisation studies but from case reports, poison information centres and observational studies. Reported findings include nausea and vomiting, constipation, dizziness, tachycardia, restlessness and seizures, as well as individual cases of cholestatic liver injury. Habituation and withdrawal symptoms with regular use have also been described. In the forensic literature, fatalities occur almost exclusively in mixed-substance constellations, which makes attribution difficult. Assessments on this are published by the European Union Drugs Agency (EUDA) and the German Federal Institute for Risk Assessment.

What surveys and self-reports can show — and what they cannot

A large share of what circulates publicly about Mitragyna speciosa comes from online surveys and forum posts. Such data are not worthless: they show how widespread something is, which patterns respondents describe themselves, and where research is needed. As evidence of a causal relationship, however, they do not suffice.

The methodological reasons are well known: self-selection of participants, no control group, no comparison against a sham treatment, unknown actual composition of the material used, recall bias and the tendency to confirm expectations. A self-report documents a perception, not a property of a substance. For codeine, by contrast, controlled clinical trials, authorisation dossiers and an official adverse-event reporting system exist. The primary literature can be searched via PubMed, among other sources.

Conclusion: why the comparison fails

Codeine and mitragynine share little more than the word alkaloid. They come from different plant families, belong to different chemical classes, are metabolised differently in the body, fall under different legal regimes and are backed by evidence bases of vastly different density. A comparison only holds when the quantities compared sit on the same level — here they do so in not a single respect.

Anyone who equates the two transfers certainty from a well-studied field into a poorly studied one. That is exactly the direction in which errors arise. This article describes botany, chemistry, metabolism, legal status and the state of research only, and makes no statement about effects, suitability or use.

Legal notice

This article is for informational purposes only and does not constitute legal advice. Its content is not intended to encourage consumption. Laws may change; the applicable regulations and information from official bodies are authoritative. Image source: https://www.kratoein.com/

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