Executive summary. GACP and GMP are complementary rather than competing standards. GACP controls the agricultural production and collection of plant material. GMP controls pharmaceutical manufacture, testing and release. The difficult part for cannabis companies is not understanding the definitions; it is defining the transition between them and ensuring that no quality risk falls into the gap.
Purpose of GACP
GACP aims to ensure consistent, traceable and hygienic production of herbal starting materials. It covers genetics, propagation, cultivation, crop protection, harvest, primary processing, storage and documentation. It addresses the biological variability and environmental exposure inherent to plant production.
In practice, most enforcement gaps trace back to GACP being treated as a lighter-touch activity than it is. A cultivation programme with weak genetic control, undocumented crop protection or inconsistent harvest timing cannot be corrected by downstream GMP testing — the variability is already baked into the material.
Purpose of GMP
GMP ensures that medicinal products and active substances are consistently manufactured and controlled according to approved requirements. It applies to facilities, equipment, personnel, documentation, validation, quality control, release and ongoing oversight.
GMP’s formal release authority is what distinguishes it from GACP: a Qualified Person is personally accountable for certifying that each batch meets its specification, and that accountability cannot be delegated to an upstream supplier however well-documented their process.
The transition point
The handover from GACP to GMP is process specific. Harvesting is normally agricultural. Extraction and formulation are clearly manufacturing. Drying, trimming, milling and packaging can sit at the interface depending on the regulatory classification and intended product. The transition should be agreed with the competent authority and reflected in licences and quality systems.
Where the transition point is left ambiguous, responsibility for deviations at the interface becomes contested during an inspection. The competent authority will expect to see the boundary defined in the site’s licence documentation, not inferred from practice.
Specifications and supplier qualification
The GMP manufacturer should define the quality requirements for the GACP material and qualify the cultivation supplier. Specifications may include identity, cannabinoid profile, moisture, microbiology, pesticides, mycotoxins, metals and foreign matter. Supplier audits should review agricultural records and post-harvest controls.
Specifications agreed with the GACP supplier should be tightened over time as batch history accumulates — a specification written before any commercial batches exist is necessarily provisional and should be reviewed once real variability data is available.
Validation and change control
GACP activities may require process qualification and evidence, even if they are not described using the full GMP validation vocabulary. Drying endpoints, cleaning, storage and transport need documented control. Cultivar, growing medium, pesticide programme and cultivation-site changes should be assessed for downstream impact.
Change control at the GACP-GMP interface is often the weakest link because cultivation changes (a new growing medium, a substituted pesticide) are made for agronomic reasons without triggering a formal quality impact assessment on the finished product.
Common failures at the interface
Recurring problems include incomplete batch genealogy, unclear responsibility for deviations, testing only after import, poorly justified drying conditions, and certificates of analysis accepted without verification. The quality agreement should define ownership of specifications, sampling, investigations, changes and records.
The quality agreement is the single most effective tool for closing these gaps — it should name, in writing, who owns sampling, who investigates deviations, and who has audit rights over the other party’s records.
Practical reference table
| Topic | GACP | GMP |
|---|---|---|
| Primary objective | Consistent herbal starting material | Consistent medicinal product or active substance |
| Typical scope | Cultivation, harvest, primary handling | Manufacture, testing, packaging and release |
| Main variability | Biological and environmental | Process and equipment |
| Release decision | Agricultural quality disposition | Independent pharmaceutical batch release |
| Validation depth | Evidence-based process control | Formal qualification and validation lifecycle |
| Inspection focus | Agricultural traceability and hygiene | Pharmaceutical quality system and data integrity |
Decision and implementation path
Common implementation mistakes
Common mistakes include choosing a country because cultivation appears attractive without confirming product access; assuming that GMP certification resolves controlled-drug permissions; using broad cannabis terminology where the active substance is not clearly defined; and relying on commercial claims that exceed the available evidence. A second recurring weakness is treating laboratories, logistics providers or cultivators as external to the pharmaceutical quality system. Outsourced work remains part of the regulated supply chain and requires qualification, agreements, performance review and change notification.
Frequently asked questions
Is GACP lower quality than GMP?
It has a different purpose. High-quality GACP is essential for pharmaceutical manufacture.
Can drying be under GACP?
Potentially, depending on product classification, process and authority expectations.
Does GMP testing compensate for poor cultivation?
No. Heterogeneous contamination may not be reliably detected by final testing alone.
Who defines the handover point?
The company should justify it with the competent authority and document it in licences and agreements.
Should GACP suppliers be audited?
Yes, when they provide critical starting material to a GMP process.
Primary references and guidance
- EMA Guideline on GACP for Starting Materials of Herbal Origin
- WHO Guidelines on GACP for Medicinal Plants
- EU GMP Guide Part I
- EU GMP Guide Part II where active substances apply
- European Pharmacopoeia, Herbal Drugs and Cannabis flower
- ICH Q9(R1)
- ICH Q10
- EU GMP Chapter 7 on Outsourced Activities
Confirm the current effective version and national applicability before operational, medical or regulatory use.