On 1 July 2024, European Pharmacopoeia monograph 3028 replaced the national cannabis flower texts of Germany, Denmark, the Netherlands and Switzerland with a single binding standard. Two years later, it's the document every EU importer's lab tests your batch against. And a revision is already working its way through consultation.
The Ph. Eur. cannabis flower monograph sets the identity, cannabinoid content, purity and contaminant tests that dried flower must pass to be used as a medicinal herbal drug in Europe. For flower prescribed to patients, it adds tighter rules: total THC and total CBD within 10 per cent of the label claim, no seeds, no leaves longer than 1.0 cm, and arsenic, cadmium and lead limits far below the general herbal drug values. A Canadian release specification written only for the domestic market can miss at least one of those lines.
What the cannabis flower monograph requires
Monograph 3028 defines the herbal drug as the dried, whole or fragmented, fully developed female inflorescence of Cannabis sativa L. It is read together with the general monograph Herbal drugs (1433), which supplies the tests 3028 doesn't repeat. The practical consequence is that one batch can carry two sets of limits, depending on whether the flower goes into extraction or is prescribed to patients as is.
Flower supplied to German pharmacies for dispensing falls into the second group.
| Test | General limit | If prescribed to patients |
|---|---|---|
| Total THC and CBD vs label | Label must state both | Within 10 per cent of label |
| Total CBN | Max 1.0 per cent | Max 1.0 per cent |
| Foreign matter | Max 2 per cent | Max 2 per cent, no seeds, no leaves over 1.0 cm |
| Loss on drying | Max 12.0 per cent | Max 12.0 per cent |
| Arsenic | Not set in 3028 | Max 0.2 ppm |
| Cadmium | Max 1.0 ppm | Max 0.3 ppm |
| Lead | Max 5.0 ppm | Max 0.5 ppm |
| Mercury | Max 0.1 ppm | Max 0.1 ppm |
Chemotype criteria
The monograph sorts flower into three types by dried-weight content:
- THC-dominant: total THC at least 5.0 per cent, total CBD no more than 1.0 per cent
- THC/CBD-intermediate: at least 1.0 per cent of each, with a THC to CBD ratio between 0.2 and 5.0
- CBD-dominant: total CBD at least 5.0 per cent, total THC no more than 1.0 per cent
Production, storage and labelling
For patient-grade flower, the inflorescence is cut at the base with minimal rachis remaining. Storage must be in an airtight container. The label states total THC and total CBD percentages and whether the drug is intended for prescription to patients. Aflatoxin B1, pesticide residues and microbial quality are not set in 3028 itself. They come through the general monograph.
The heavy metal column is where lab reports split, and our guide to cannabis contaminant testing limits covers the wider panel. The patient-use limits were set with inhalation exposure in mind, using the ICH Q3D approach to elemental impurities, and a cadmium result that passes at 1.0 ppm fails at 0.3 ppm. Specify the stricter column from the start.
What the Pharmeuropa 37.4 revision changes
The EDQM published a revised text of monograph 3028 in Pharmeuropa 37.4 on 2 October 2025, with comments closing on 31 December 2025. The draft changes three things that Canadian exporters care about.
- Seeds: the absolute "no seeds" rule for patient-use flower becomes "no mature seeds." Immature seeds turned out to be common in flower already prescribed in some member states.
- Leaves: the ban on leaves longer than 1.0 cm drops out. Leaves would be controlled only by the general 2 per cent foreign matter limit.
- Identification test C: the HPTLC acceptance wording for the THC zone in THC-dominant flower widens to "very faint to equivalent (may be absent)."
The third change has a clear origin. Broughton showed that freshly dried THC-dominant flower can carry THC below the HPTLC detection threshold, because THC mostly forms later from THCA. The expert group reviewed that submission in June 2025. Four months later, the fix was in a public draft. That's fast for a pharmacopoeia, and it tells you the Ph. Eur. Commission responds to real test failures when producers bring data.
A Pharmeuropa draft is not an official standard. The EDQM says so plainly: a draft becomes binding only once the Commission adopts it and it's published in the Ph. Eur. Until then, the current text governs every batch you release. Don't loosen your trim or seed controls on the strength of the draft.
Where Canadian release specifications fall short
Health Canada doesn't hand you a cannabis flower table to copy. The Cannabis Regulations require testing against reference standards from a pharmacopoeia listed in Schedule B to the Food and Drugs Act, and the European Pharmacopoeia is on that list. So the monograph is already a recognised Canadian reference. The gap is that most LP specifications were written for the domestic channel and then stretched for export.
A five-line comparison closes most of that gap before an EU-bound batch is released. Call it the 3028 Release Gap Check:
- Heavy metals. Is the release limit for arsenic, cadmium and lead set at the patient-use values, or at the looser general values?
- Total CBN. Does the specification carry a CBN limit at all? Many domestic specs report CBN without a pass criterion.
- Foreign matter method. Is it tested per Ph. Eur. 2.8.2 on a 25 to 50 g portion, with seeds and leaf length recorded, or judged visually on the trim line? Our note on sampling plans for batch testing covers how that portion should be drawn.
- Moisture basis. Loss on drying under the monograph method is not the same number as water activity. Our note on cannabis water activity and moisture limits explains why both belong on the certificate.
- Label tolerance. Will your label claim survive the importer's retest within 10 per cent? The reasons results drift are covered in why EU retest numbers differ from your COA.
Watch line three. A trim crew working to a domestic visual standard can pass flower that an EU lab rejects for leaf length or a stray seed, and nobody finds out until the retest.
Building a monograph-ready batch
Monograph compliance is decided long before the sample reaches a lab. It starts with cultivation under GACP controls, runs through drying and trimming, and ends with a certificate that maps line by line to 3028.
Write the specification in two columns
Keep your Health Canada release limits and your 3028 patient-use limits side by side on one specification. Where they differ, the EU-bound lot is released to the stricter figure. Your importer's qualified person will compare your certificate to that column anyway, as our guide to EU QP batch release sets out.
Use a lab that runs the monograph methods
An ISO/IEC 17025 accredited lab is the baseline, and our checklist for ISO/IEC 17025 cannabis testing lists what importers verify. Ask whether its cannabinoid assay follows the 3028 liquid chromatography method, including the CBN calculation, and whether its foreign matter procedure follows 2.8.2. A lab that reports compliance with "Ph. Eur. limits" while running an in-house potency method is only half-aligned.
Trim to the current text, not the draft
Hand-trimming removes leaf and rachis in a way that holds up under a 25 to 50 g foreign matter examination. Our comparison of hand-trimmed and machine-trimmed flower covers the export trade-offs in more detail.
AlphaLeaf is a Montreal-based Health Canada Licensed Producer growing premium indoor flower from refined genetics, hand-trimmed and batch-tested by an ISO/IEC 17025 accredited laboratory. We hold export authorisation under the Cannabis Act and keep EU-GMP-aligned documentation and full batch traceability for importers supplying the German and wider EU medical channel. You can review our certifications before you request a specification.
The monograph text is public, and its limits don't change from one batch to the next. Whether a lot clears an EU lab depends on which column your specification was written against. Check that first. To compare your current specification with 3028, talk to our team.
Frequently Asked Questions
What does the Ph. Eur. cannabis flower monograph test for?
Monograph 3028 covers identification, chemotype classification, total THC and total CBD content, total CBN, foreign matter, loss on drying and the heavy metals arsenic, cadmium, lead and mercury. Aflatoxin B1, pesticide residues and microbial quality are covered through the general monograph Herbal drugs (1433).
When did the European Pharmacopoeia cannabis flower monograph take effect?
It was adopted by the Ph. Eur. Commission in June 2023, published in Supplement 11.5 in January 2024 and became the binding standard on 1 July 2024, replacing national monographs such as the German, Danish, Dutch and Swiss texts.
What heavy metal limits apply to cannabis flower prescribed to patients?
For flower prescribed to patients, the monograph sets arsenic at 0.2 ppm, cadmium at 0.3 ppm, lead at 0.5 ppm and mercury at 0.1 ppm. The general limits for cadmium and lead are 1.0 ppm and 5.0 ppm.
Can medical cannabis flower contain seeds or leaves under Ph. Eur. 3028?
Under the current text, flower prescribed to patients must contain no seeds and no leaves longer than 1.0 cm, within an overall foreign matter limit of 2 per cent. The Pharmeuropa 37.4 draft proposes allowing immature seeds and controlling leaves through the 2 per cent limit alone.
Is the revised cannabis flower monograph in force?
Not until the Ph. Eur. Commission adopts it and it is published in the Ph. Eur. The draft appeared in Pharmeuropa 37.4 in October 2025 with comments closing on 31 December 2025. Until adoption, the current text applies.
Do Canadian LPs have to meet the Ph. Eur. monograph?
For EU medical supply, in practice yes, because importers test against it. In Canada, the Cannabis Regulations require reference standards from a pharmacopoeia listed in Schedule B to the Food and Drugs Act, and the European Pharmacopoeia is one of them.
