A line manager deciding whether an employee is fit to operate machinery is not being asked to interpret a drug test, and should not be put in that position. That judgement is routed to occupational health instead, consistent with the individual risk assessment set out in Chapter Five.

Training managers for real scenarios

‘Training should use realistic scenarios and explain what to ask, what not to ask and when to involve HR or occupational health. Our stakeholder sessions show that managers generally need practical decision-making tools, not lengthy legal theory.

‘The better employers incorporate medical cannabis into existing medicines and disability procedures while providing specific guidance on testing and stigma. Some are also consulting patients and clinicians rather than designing policies around assumptions.’ – Rupa Shah

Designing guidelines which are informed by information from both patients and clinicians is a simple and essential first step for employers, ensuring that the policies directly impacting medical cannabis patients are built in collaboration with them. 

Where policy goes next

‘Medical cannabis will become a routine part of medicines policies, particularly in transport, healthcare and other safety-sensitive sectors. I also expect greater scrutiny of tests that identify historic THC exposure without establishing current impairment.’ – Rupa Shah

The Care Quality Commission recorded a 118% increase in unlicensed cannabis prescriptions between 2021 and 2023, a growth rate industry figures including Medical Cannabis Clinicians Society founder Professor Mike Barnes have flagged as reaching a ‘tipping point’ for scrutiny. 

A patient population growing that quickly is, on current form, arriving in workplaces faster than employer policy is catching up.

While the UK government’s current guidance on medical cannabis for employers is currently lacking, by implementing informed, common sense and pre-existing policies to the individual employee, these all-too-common workplace disputes can be mitigated or effectively avoided. 

Employer Policy Checklist

A workplace medical cannabis policy should:

• Explicitly distinguish lawfully prescribed medical cannabis from recreational use in medicines, drug-testing and disciplinary policies.
• Provide a confidential, named disclosure route that does not run through a line manager by default.
• Require individual risk assessment – the employee’s actual tasks and role, not the substance in the abstract – before any restriction is applied.
• Treat a positive THC test as the start of an assessment, not proof of impairment or grounds for automatic sanction.
• Apply the least restrictive effective control first (adjusted dosing times, temporary duties, additional review), with exclusion from a role as a last resort.
• Route fitness-for-work and safety judgements to occupational health, not to untrained line managers.
• Limit information-sharing to what a manager needs to implement an adjustment, not the full clinical picture.
• Request only necessary and proportionate evidence of a prescription, not full medical records, as a default.
• Apply the same rigour used for other medicines that can affect performance (opioids, benzodiazepines, sedatives), rather than a harsher standard for cannabis specifically.
• Be paired with manager training built on realistic scenarios – what to ask, what not to ask, and when to escalate to HR or occupational health.
• Be developed with input from patients and clinicians, not drafted around assumptions about either.