Should You Tell Your Employer You’re Prescribed Medical Cannabis?

Written By

Dr. Hannah Clarke

MBChB, MRCGP Specialist in Pain Management

Medical Reviewed By

Dr. James Wilson

MBBS, BSc, MRCGP General Practitioner

A medical cannabis prescription can feel deeply personal, especially if you work in a role involving driving, machinery or other safety responsibilities. There is no single answer that applies to every job or workplace. Whether to tell your employer you’re prescribed medical cannabis depends on your specific role, your employer’s policy, and whether your medication could affect your ability to work safely.

Key Takeaways

Whether to disclose depends on your job duties, workplace policy and whether the medicine could affect safe work.
A legal prescription does not make it acceptable to work, drive or operate machinery while impaired.
Safety-sensitive roles need early, confidential discussion rather than assumptions.
Keep your prescription and clinical documentation available if you choose or need to disclose.

Is There a Legal Duty to Tell Your Employer?

Not always. There is no single UK law requiring every employee to disclose a medical cannabis prescription to their employer. However, disclosure duties can arise from several different sources: your employment contract, your employer’s medicines or drug and alcohol policy, sector-specific regulatory requirements, and your general health and safety responsibilities at work.¹

These are separate from any universal cannabis rule. In safety-sensitive industries including transport, healthcare, construction and security, specific obligations may apply regardless of whether a medicine is prescribed. If you are unsure what your contract or policy requires, the appropriate first step is to read the relevant documents and, if needed, seek confidential advice from a union representative or HR.

Cannabis-based products for medicinal use (CBPMs) are lawfully prescribed medicines.² A prescription does not automatically affect your employment status, but it does not override employer policies or safety responsibilities.

When Disclosure Is Usually More Important

The relevant question is not whether your prescription is legal, but whether your medication could affect your capacity to work safely.

May warrant a conversation	Questions to consider
Driving or operating vehicles	Does your medication currently affect alertness or reaction time?
Operating machinery or working at height	Have you noticed any drowsiness, dizziness or coordination changes?
Clinical, care or emergency services	Does your role require continuous alertness or clinical decision-making?
Security or aviation work	Are you subject to drug and alcohol testing as part of your role?
Roles with strict fatigue or alertness requirements	Does the timing of your dose affect your fitness at the times you work?

The effects of CBPMs vary by medicine, formulation, dose and individual response. You must not drive, operate machinery or carry out safety-critical tasks if you feel drowsy, dizzy or otherwise impaired, regardless of whether you hold a valid prescription.

What About Workplace Drug Testing?

Some CBPMs, particularly those containing tetrahydrocannabinol (THC), may produce a positive result on a workplace cannabinoid test. A prescription can be relevant evidence if a test is positive, but it does not automatically resolve every workplace issue. Impairment, policy breach or a safety concern remains a separate matter.

For medical cannabis work in the UK settings, the clearest approach is to check your employer’s drug and alcohol policy before testing occurs where possible. If your role involves regular or random testing, seeking confidential occupational health or HR advice before starting treatment is sensible. Do not attempt to second-guess how a test will be conducted or interpreted.³

How to Have a Practical Conversation

If you decide to disclose, or if your employer raises the issue first, a structured approach is more useful than an unplanned disclosure.

Check the policy first: Know what your employer’s medicines disclosure and drug and alcohol rules actually say before the conversation.
Decide who needs to know: A line manager, occupational health provider and HR each serve different functions. A health disclosure to occupational health is confidential; a conversation with a manager may not be.
Share relevant information, not medical detail: You do not generally need to describe your diagnosis, dosage or formulation. Functional implications, timing and any adjustment that might be needed are usually more relevant.
Agree a review process: If your role involves monitoring, agree how any safety concern or change to your condition would be reviewed and by whom.

Where disability law may apply, reasonable adjustments can be a legal question. Individual employment or union advice is more appropriate than this article for those circumstances.

What to Keep on File

Retain a copy of your prescription label or dispensing documentation, your clinician’s contact details or clinical correspondence where appropriate, and a copy of the relevant employer policy or any written agreement reached. An employer handling your health information has confidentiality obligations, but detailed data protection advice should come from an independent source.

If You Are Considering Treatment

A specialist assessment considers your full medical history, current medicines, daily life and potential safety factors before any prescribing decision. It may also help to understand how a medical cannabis consultation works before deciding whether to explore treatment.

If you have ongoing symptoms and want to know whether a specialist assessment may be appropriate for your situation, you can check whether you may be eligible with a specialist consultation.

Frequently Asked Questions

Can my employer dismiss me for having a medical cannabis prescription?

Not automatically. Employment decisions involving health conditions and medication must comply with employment law, including where a disability is involved. However, a prescription does not protect an employee from disciplinary action related to genuine impairment at work, a policy breach or a safety incident. Individual employment or union advice is recommended for specific circumstances.

Do I need to tell my employer before a workplace drug test?

There is no universal rule. If your employer conducts drug testing, reviewing their policy and seeking occupational health or HR advice before testing is sensible, particularly if your CBPM contains THC. A prescription can be disclosed as context if a positive result occurs, but outcomes depend on the specific policy and circumstances.

Can I drive for work with a medical cannabis prescription?

You must not drive if you feel impaired, regardless of your prescription status. The UK legal THC blood limit applies to prescribed patients as it does to everyone. If your CBPM affects your alertness or reaction time, you should not drive. Your prescribing clinician can advise on timing and impairment risks.

Should I tell occupational health about prescribed medical cannabis?

Occupational health advice is typically confidential and focused on your fitness for your specific role. Telling an occupational health provider about a current prescription allows them to give more accurate fitness-to-work guidance and to support you through any workplace adjustment discussion.

Does an employer have to make adjustments for prescribed medicine?

Where a medical condition amounts to a disability under the Equality Act 2010, an employer may have a duty to consider reasonable adjustments. Whether a specific adjustment is required is a case-specific question that depends on the role, the condition and the employer’s circumstances. Individual employment or union advice is appropriate.