Dear Umesh,
My work has contacted my clinic with an occupational health request about my medical cannabis prescription, and I’m worried I’m going to lose my job. What do I need to know?
First, take a breath. An Occupational Health assessment doesn’t automatically mean bad news. However, I understand your concern, and you’re right to want to understand what’s happening.
To be transparent, I am not a Human Resources (HR) or Occupational Health (OH) professional, nor do I claim to be. While I have previously been a member of the Chartered Institute of Personnel and Development (CIPD) and have helped develop HR teams within organisations, I am not writing in a professional advisory capacity.
Nothing in this article should be taken as legal or employment advice. Anyone facing workplace issues should seek guidance from an HR professional, employment specialist or solicitor. What I can do is share what I’ve learned from a recent case and give you some practical questions to ask your employer.
An emerging trend
Around a month ago, a prescribing clinician shared an email with fellow professionals after being contacted by the Occupational Health department of one of their patients’ employers. The situation is very similar to yours.
While it’s entirely normal for Occupational Health practitioners to seek additional medical information to assess an employee’s fitness for work, the wording of this particular questionnaire stood out because it focused almost exclusively on medical cannabis rather than the individual’s overall fitness for employment.
All the questions were prefaced as “Please provide your opinion” Among the questions asked were:
- What is the likely duration of impairment following administration of the prescribed medication?
- Could residual or next-day impairment occur?
- What minimum period should elapse between taking the medication and driving?
- Is the prescribed dosage likely to result in blood THC concentrations above, below or close to the UK’s legal driving limit?
- What level of functional impairment is likely while the patient complies with the prescribed treatment?
- How confident is the clinician that the patient can safely operate a motor vehicle, with driving being used as a proxy for other safety-critical duties?
What is concerning about these questions
My immediate advice to the prescribing clinician was to proceed carefully.
The questionnaire repeatedly requested the doctor’s personal opinion rather than objective clinical facts. Depending on the circumstances, responses of this nature could potentially be relied upon in future employment disputes, including capability or constructive dismissal proceedings.
What was particularly notable was that every question centred on medical cannabis itself and not fitness to work.
Many commonly prescribed medicines – including antidepressants, opioid pain medication and anti-epileptic drugs – can impair concentration, reaction times and cognitive function, sometimes to an equal or even greater extent than prescribed cannabis, especially when they are a part of a cocktail of medications that together may have a multiple rather than a cumulative effect. Yet employers generally manage these medications through standard medicines and fitness-for-work policies rather than creating medication-specific assessments.
This raises an important question for you: why is your medical cannabis being treated differently from other prescribed medications?
What your employer should actually be assessing
Occupational Health has an important role in protecting both employees and employers by determining whether someone is medically fit to perform their duties safely.
However, that assessment should focus on your functional ability – for example, can you do your job safely? – not just what medication you are taking.
Your employer should assess it in the same way they would any other prescribed medication that may affect performance. This includes considering whether reasonable workplace adjustments are appropriate, such as altered duties, revised shift patterns, additional breaks or other practical accommodations.
The key issue should always be whether you can safely perform your role, not the name of the medication.
What your employer actually needs
In most cases, employers do not require detailed medical records.
Instead, Occupational Health assessments typically seek answers to practical questions such as:
- What medical condition is being treated?
- Is the employee fit to undertake their role?
- Are there side effects that could affect work performance?
- Are any reasonable adjustments recommended?
- Are there any safety concerns relevant to the employee’s duties?
If your assessment focuses almost entirely on the fact that you’re prescribed medical cannabis, rather than your overall fitness for work, it’s fair to ask why.
You’re also entitled to understand why medical information is being requested, and Occupational Health generally requires your consent before obtaining reports from your treating clinician.
Questions you should ask your employer
If your prescribing clinic receives a questionnaire from your employer or Occupational Health provider, here are the questions I’d recommend asking:
- What is the purpose of the assessment?
- Which aspects of my role are being evaluated?
- Is the assessment focused on my fitness for work?
- Are reasonable adjustments being considered?
- Why does the questionnaire appear to focus specifically on my prescribed medication rather than my overall medical condition?
These questions may help ensure that any assessment remains proportionate and relevant to your role.
You still need to be honest
None of this should be interpreted as suggesting that you should withhold information about prescribed medication.
If you take any medicine that may impair your ability to work safely, full disclosure is essential, not only for your own protection but also for the safety of colleagues and the public.
This is particularly important in safety-critical occupations such as professional driving, operating heavy machinery, aviation, emergency services and similar roles. In these situations, your employer may need to consider temporary or permanent adjustments to ensure work can be carried out safely.
The bottom line
You have a right to be assessed on your ability to do your job safely, not on assumptions about your medication. If your Occupational Health assessment seems disproportionately focused on the fact that you’re prescribed cannabis rather than your fitness for work, the questions above will help you understand what’s really happening.
And remember: while it’s natural to feel anxious, an OH assessment is a normal part of workplace health management. Most medical cannabis patients continue working successfully with appropriate adjustments or no changes at all.
If you’re still concerned, speak to an employment solicitor or your union representative before the assessment takes place. They can review any questionnaires being sent to your clinic and ensure your rights are protected.

