Where does GMP start for medical cannabis?
Four EU texts pass the question to each other: how GACP, Annex 7, Part II and ICH Q9 build a defensible GMP boundary for cannabis.
No single European text answers this question, and that is the honest starting point. Four documents pass it to each other: the EMA GACP guideline says that “in some circumstances” drying and cutting should follow GMP and points to Annex 7; the Annex 7 table is the only place where one activity, cutting and drying, sits under GACP, GMP Part II and Part I at the same time; the explanatory note assigns the classification to the use of the material and the responsibility to the manufacturer of the medicinal product; Part II then requires that manufacturer to “designate and document the rationale” for where active substance production begins, case by case. I built my August 2026 webinar with Christopher Tasker of Global Cannabinoid Solutions around exactly this route, because the answer is a route, not a slogan: GMP starts where you can designate it, document it and defend it with science and risk.
What is the difference between GACP and GMP?
The difference is regulatory architecture, and reducing it to quality against no quality gets the whole boundary wrong. As I put it during the webinar, it would be completely misleading to describe GACP as no quality and GMP as quality: the real distinction lies in the nature of the responsibilities and in the depth and formality of the evidence required to demonstrate control. GACP, in the EMA guideline now at Revision 1, covers cultivation, collection, harvesting and primary processing of herbal substances, and it states its own aim in pharmaceutical terms: the quality of these starting materials requires “an adequate quality assurance system”. GMP, in EudraLex Volume 4, governs the manufacture of the active substance (Part II) and of the medicinal product (Part I). A grower under GACP is not outside quality. The question is where one architecture hands the material to the other.
Which rules apply to drying and cutting?
Drying and cutting are exactly where the handoff happens, and the GACP guideline says so itself. Section 12 on primary processing requires drying to start “as soon as possible after harvesting”, then adds the sentence that carries the weight: “In some circumstances drying and cutting should be performed according to EudraLex Volume 4 GMP part I or II (refer the GMP Table in Annex 7)”. During the webinar I called this a genuine regulatory handoff: the document follows the material from cultivation to primary processing and, precisely at drying and cutting, stops giving a self-contained answer and names the text where the decision continues. The first question that follows is the one I asked the audience: what circumstances? For that, you go where the GACP sends you, the table of Annex 7.
What does the Annex 7 table decide?
The table decides less than the market thinks, and that is its value. In the Annex 7 grid, “cutting, and drying of plants” is the only row marked under all three regimes: GACP, Part II and Part I. The asterisked note resolves part of it, “GMP is applicable to further cutting and drying steps”, and the explanatory note gives the rule that carries everything else. The GMP classification of the herbal material “is dependent upon the use made of it by the manufacturing authorisation holder”, and:
It is the responsibility of the manufacturer of the medicinal product to ensure that the appropriate GMP classification is applied.
Classification follows use. The same dried flower can be an active substance, an intermediate or, once packaged for supply, part of a finished product, and the answer depends on what the authorisation holder does with it, not on the name of the operation.
Who sets the GMP starting point, and how?
The manufacturer sets it, and the texts demand a defensible file, not a habit. EU GMP Part II (section 1.2) requires the manufacturer to “designate and document the rationale for the point at which production of the active substance begins”, established case by case for processes like extraction. Three words carry the load: designate a concrete point, document it in evidence a third party can read, and support it with a rationale. An oral statement or an industry habit is not sustainable in front of a legislator, which is how I framed it on 25 August. The same section adds that GMP stringency “should increase as the process proceeds”, a gradient that works inside active substance manufacturing and does not move the boundary itself. ICH Q9(R1) supplies the method for the rationale: risk evaluation “based on scientific knowledge” and ultimately linked “to the protection of the patient”. Drying science shows the step is critical; the classification still has to be built from use, material status and documented risk, not from criticality alone.
What does this mean for a cannabis supply chain?
It means the boundary is a governance decision that someone must own, document and defend, and in cannabis that weight lands early. In much of the medical cannabis market the product moves without an ordinary marketing authorisation, so the external document the three texts point to has to be read as the applicable national authorisation or lawful supply route, and the classification decision falls back on the manufacturer who uses the material. Authorities are already probing this exact seam: in 2026 the pharmaceutical supervisory authority of the German Land of Hesse, one Land authority rather than the federal BfArM, circulated a note reading the controlled drying of cannabis flowers as a critical manufacturing step. Whatever weight you give that interpretation, buyers now ask suppliers for the boundary file: where GMP starts, designated, documented, reasoned. My working rule, stated at the webinar, applies to both sides of that conversation: we should not invent any commercial wording to explain GACP or GMP. We should always go back to the guidelines.
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