Medical Cannabis and Driving in the UK

Where Relief Meets Possibility

Driving is part of everyday life in the UK, whether it’s the school run, commuting to work, or simply visiting family. For patients prescribed medical cannabis, one of the most common concerns is: “Can I still drive legally and safely?”

The short answer is yes—you can drive if you’re prescribed cannabis-based medicines, but only if you’re not impaired and you can show evidence of your prescription. This page explains everything you need to know about medical cannabis and driving, from UK laws and patient responsibilities, to what happens if you’re stopped by police.

The Law: Medical Cannabis and Driving

In the UK, cannabis is still classed as a Class B drug under the Misuse of Drugs Act 1971. But since November 2018, cannabis-based medicines have been legal for patients with a prescription from a specialist doctor registered with the GMC (General Medical Council).

THC Limits and Driving

The law sets strict limits for certain controlled drugs in the blood. For THC (the main psychoactive component in cannabis), the limit is 2μg/L of blood—a level so low that almost any patient taking THC-based medicine will exceed it.

This is where the “statutory medical defence” applies. If you are prescribed a cannabis medicine, you can legally drive as long as you are not impaired and can provide evidence of your prescription.

📖 Source: UK Government – Medical Cannabis and Road Safety

What This Means for Patients

If you’re a medical cannabis patient:

✅ You are legally allowed to drive if prescribed by a specialist.
✅ You must not drive while impaired.
✅ You should always carry proof of your prescription.
✅ You can raise a statutory medical defence if stopped.

However, if you drive while impaired—even with a prescription—you can still face prosecution.

Patient Responsibilities

To protect yourself and others, you have a few key responsibilities when driving with a prescription.

1. Never Drive While Impaired

It is illegal to drive if your ability is affected by medicines. You may be impaired if you experience:

  • Sleepiness or drowsiness
  • Slowed reaction times
  • Poor coordination
  • Dizziness or blurred vision
  • Changes in thinking or judgment

⚠️ Impairment is most likely when:

  • You first start treatment
  • Your dose is increased or decreased
  • You’re taking other medications that interact with cannabis
  • You’re drinking alcohol alongside your medicine

If in doubt—do not drive.

2. Follow Your Doctor’s Guidance

Always stick to the instructions given by your prescribing specialist. This includes dose, timing, and how your medication interacts with other treatments.

3. Carry Evidence with You

If stopped by police, being able to show your prescription is vital. Keep the following with you:

  • A copy (paper or digital) of your prescription
  • Photo ID (driving licence, passport, or ID card)
  • If possible, a letter from your prescribing consultant
  • Your medicine in its original packaging with your name clearly labelled

What to Do If You’re Stopped by Police

Many patients worry about being pulled over. Here’s what to do if it happens:

  1. Stay calm and polite.
  2. If asked, explain that you have a legal prescription for medical cannabis.
  3. Show your prescription and ID.
  4. If they request a roadside swab, you can remind them that your medicine is legally prescribed. However, refusing a test may count as a separate offence, so it’s usually best to comply.
  5. If arrested, request legal representation immediately and explain your statutory medical defence.

📖 Helpful patient guide: Cannabis Industry Council – Cannabis Driving Guidance

Do You Need to Tell the DVLA?

One of the most common questions patients ask is whether they need to tell the DVLA about their prescription.

  • Mandatory reporting: Only patients prescribed cannabis for epilepsy must legally inform the DVLA.
  • Strongly advised: For all other conditions, the DVLA recommends informing them if your medicine may affect your ability to drive. This is seen as a precaution and shows you are acting responsibly.

📖 Source: NHS – Medical Cannabis

Cancard and Police Recognition

Some patients choose to carry a Cancard, a medical cannabis ID card recognised by many UK police forces.

  • Cancard provides validation that you’re consuming cannabis for medical reasons.
  • It is not mandatory but may help avoid misunderstandings.
  • Remember: Cancard is not a prescription. You must still carry your official documents.

📖 Learn more: Cancard – Official Site

FAQ

Can I drive after smoking medical cannabis in the UK?

Yes, if you are prescribed it and not impaired. However, THC can remain detectable in the bloodstream for weeks. The law focuses on impairment and whether you can show a prescription.

Do I need to report medical cannabis to DVLA?

Mandatory only for epilepsy. Strongly recommended for other conditions if there’s any chance of impairment.

Do police recognise Cancard?

Yes, many do, but it is not an official substitute for your prescription or ID.

Is it worth getting a Cancard?

It can be helpful but is optional. Having your prescription and ID is what legally matters.

Do I have to identify myself to police?

You don’t need to give personal details unless police have reasonable grounds to suspect an offence. If stopped for drug driving checks, you’ll need to show your prescription and ID.

Safety First: Tips for Patients

  • Avoid driving when starting or changing your dose.
  • Never mix alcohol with cannabis medicines.
  • Check your other medications for possible interactions.
  • Be honest with your doctor if you feel drowsy or unsafe behind the wheel.

Ongoing Research and Evidence

The UK continues to research medical cannabis and road safety. Government-funded trials and real-world data (such as the UK Medical Cannabis Registry) are shaping guidance for patients and clinicians.

So far, evidence shows that patients using prescribed cannabis responsibly pose no greater risk on the road than those taking other impairing medicines (like opioids or sedatives).

Medcann Pharmacy: Compassionate Care, Clear Guidance

At Medcann Pharmacy, we understand that driving is part of independence. Our role is to help you access safe, legal treatment without fear or confusion. We provide:

  • Trusted prescriptions through qualified doctors
  • Guidance on safe use and patient responsibilities
  • Up-to-date information on UK driving laws and cannabis

✨ Because your health deserves more options.

Summary

  • Driving on prescribed medical cannabis is legal in the UK if you are not impaired.
  • The statutory medical defence protects patients who can show proof of prescription.
  • Always carry your prescription, ID, and medicine packaging.
  • Inform the DVLA if necessary and follow your doctor’s advice.
  • Cancard may help but is optional.

Ready to Take the Next Step?

Break free from barriers—get safe, legal access to medical cannabis today.

📞 Call us: 020 8123 8883
📧 Email us: info@medcannpharmacy.co.uk

Medcann Pharmacy – Your Health, Your Choice.