Why this matters
If you are prescribed medical cannabis, your clinician needs a full picture of everything you take, including products bought without a prescription. This includes CBD products, herbal remedies, sleep aids and other supplements.
The reason is safety. CBD and THC can affect how other medicines work, and supplements are worth disclosing so the clinical team can assess the full picture. Your prescriber and pharmacist are best placed to assess these interactions, but they can only do so if they know what you are taking.
This guide explains why disclosure matters and what to tell your clinic. It does not give interaction advice, that is a conversation for your clinical team.
What counts as a supplement for disclosure purposes
When we say “supplements,” we mean any product you take by mouth that is not a prescribed medicine. This includes:
- CBD oils or pastes bought from health shops, online retailers or pharmacies without a prescription. These are not the same as prescribed medical cannabis, and their strength and purity are not regulated in the same way.
- Sleep aids and herbal remedies. Include any product you use regularly or occasionally.
- Other supplements. Include vitamins, minerals and herbal products, even if you are unsure whether they matter.
If you are unsure whether something counts, it is safer to mention it. Your clinic will not judge you for taking over-the-counter products, they need the information to keep your treatment safe.
Why the full list matters
The clinical team needs the name of each product, how often you use it and the dose shown on the label. This helps them assess possible interactions and decide whether any follow-up is needed. Do not stop or start a supplement on the basis of this page.
CBD products bought outside the prescription route are not the same as prescribed medicines. Bring the label or a photo of it to the appointment if you can.
What to ask your clinic or pharmacy
- “Should I stop any of my current supplements before starting medical cannabis?”
- “Are there any supplements I should avoid while using this medicine?”
- “How do I add a new supplement to my medication list for your records?”
- “Can you check whether my herbal sleep product interacts with my prescription?”
- “What should I do if I notice increased drowsiness after starting a new supplement?”
These questions help you get clear, personalised advice without changing anything on your own.
What this guide cannot decide for you
This guide explains why disclosure matters, but it cannot tell you whether a specific supplement is safe to take with your prescribed medical cannabis. That depends on your full medical history, your current medicines, and the specific product you are using.
Only your prescriber or pharmacist can give you interaction advice. Do not stop or start any supplement without discussing it with your clinical team first.
Read next
- CBD and medical cannabis: what patients should know
- Medical cannabis and other medicines: preparing a safe medication list
- Questions to ask before choosing a medical cannabis clinic
Sources
- https://www.nhs.uk/medicines/medical-cannabis/
- https://www.nice.org.uk/guidance/ng144
- https://www.england.nhs.uk/long-read/cannabis-based-products-for-medicinal-use-cbpms/
- https://www.gmc-uk.org/professional-standards/learning-materials/information-for-doctors-on-cannabis-based-products-for-medicinal-use
- https://www.cqc.org.uk/guidance-providers/healthcare/cannabis-based-medicinal-products-what-cqc-expects-providers
