As medical cannabis prescriptions become more common in the UK, police officers are increasingly likely to encounter individuals lawfully in possession of cannabis-based products for medicinal use. However, verifying whether that possession is legal — and ensuring that prescriptions are valid — can still present operational challenges.
This article provides clear, practical guidance for UK police forces on how to verify the legitimacy of a medical cannabis prescription during a stop, search, or enquiry.
1. Ask for Evidence
If someone claims to be legally prescribed medical cannabis, you may ask them to present:
- A valid private prescription – typically issued by a GMC-registered specialist doctor.
- The original packaging with a dispensing label from a licensed pharmacy.
- A clinic letter or patient summary confirming ongoing treatment.
The patient is not legally required to carry all this documentation, but producing it can help officers make an informed decision at the point of contact.
2. Understand the Prescription Components
A valid medical cannabis prescription in the UK should include:
- The name and GMC number of the prescribing doctor.
- The date issued and dosage instructions.
- The name of the product, which may include THC and/or CBD content.
- The patient’s name.
- Details of the licensed dispensing pharmacy, including their GPhC number.
3. Check the Doctor’s Credentials
The prescribing doctor must be:
- Listed on the General Medical Council (GMC) Specialist Register
- Practising within a relevant specialty (e.g. neurology, pain medicine, psychiatry)
- Based in the UK and qualified to issue Schedule 2 controlled drugs.
You can verify the prescriber at: www.gmc-uk.org
4. Verify the Dispensing Pharmacy
The product must be dispensed by a licensed UK pharmacy — not imported or supplied informally. The pharmacy label usually includes a GPhC number.
Verify pharmacists here: www.pharmacyregulation.org
Note: GPhC numbers are not used to verify doctors.
5. Be Aware of Red Flags
Officers should be cautious if:
- The prescription appears handwritten or lacks detail.
- The prescriber is not on the GMC register.
- The product is in plain packaging with no pharmacy label.
- The patient refuses to share information or shows signs of driving impairment.
6. Contact the Clinic or Pharmacy (If Needed)
If time permits, contact the clinic or pharmacy listed on the documentation to confirm:
- The legitimacy of the prescription.
- The patient is under their care.
- The product was legally dispensed.
Clinics are typically cooperative with law enforcement verification requests.
7. Medical Cannabis ID Cards (e.g. Cancard)
While not a legal document, some patients carry a Cancard. It is not proof of a prescription but may indicate that the individual is a registered patient and should not be treated as a recreational user.
Police forces are encouraged to use discretion and refer to their internal guidance.
8. Driving and Impairment
Even with a legal prescription, it remains an offence to drive if impaired. Officers may still:
- Conduct a field impairment test.
- Use a toxicology screen if necessary.
The legal THC limit for driving is 2µg/L of blood, but this is subject to change depending on legal developments and case law.
Key Takeaways
- Always verify the GMC number of the prescribing doctor (not GPhC).
- Cross-reference the pharmacist’s GPhC number if needed.
- Evaluate the product packaging, labels, and consistency of documentation.
- Use internal force guidance and consult drugs liaison officers or legal advisors when in doubt.
