Before the Theatre List: A Calm UK Guide to CBD and Planned Surgery

Why the pre-assessment form asks about supplements

A planned operation rarely begins in the theatre. It begins with paperwork: a referral, a pre-assessment questionnaire, perhaps a telephone call with a nurse, then a consent conversation with a surgeon. Among the questions about allergies, previous anaesthetics and regular medicines, there is often a line about supplements. CBD belongs on that line.

In the UK, CBD is not licensed as a medicine. Most products are sold as food supplements, cosmetics or general wellness items, and the label may describe them in everyday language rather than clinical terms. That can make CBD feel separate from the medicine cabinet. For an anaesthetist, however, anything taken regularly is part of the picture. The aim of disclosure is not to invite judgement. It is to help the clinical team plan safely.

What anaesthetists are trying to understand

Anaesthesia is not a single drug but a carefully managed process. The team considers how medicines are metabolised, how blood pressure and heart rate may respond, how sedating a product might be, and whether other medicines could interact. They also need to know what a patient takes routinely, because stopping or continuing a product around surgery can matter.

CBD is a case in point. Laboratory studies suggest that cannabidiol can affect some liver enzymes involved in drug metabolism, although the clinical significance in humans is often uncertain. Some anaesthetic drugs are processed by the liver. There are also theoretical questions about additive sedation, changes in blood pressure, and interactions with medicines used for pain, anxiety or sleep. These are not reasons for alarm. They are reasons for a clear record and a sensible conversation.

The evidence base is still limited. There is no large body of UK clinical guidance saying that every patient must stop CBD at a fixed number of days before surgery. Practice may vary according to the product, the dose, the procedure and the patient's other medicines. That is why the most useful thing a patient can do is disclose honestly and ask what the team would prefer.

CBD is not the same as prescribed cannabis

It is worth separating over-the-counter CBD from cannabis-based medicinal products prescribed by a specialist. Prescribed products are medicines and should always be declared to the surgical team. They may contain THC or other cannabinoids, and stopping them abruptly without advice can be inappropriate. The same principle applies to any CBD product used regularly: do not make a sudden change simply because surgery is approaching. Ask first.

What to bring to the appointment

A short written record is more useful than a vague memory. The pre-assessment nurse or anaesthetist does not need a essay; they need facts they can act on.

• The product name, manufacturer and batch number if available.
• The stated strength, such as milligrams per millilitre or milligrams per capsule.
• How much you take, how often, and the time of your last dose.
• Whether the label mentions other cannabinoids, terpenes or added ingredients.
• The carrier oil or base, especially if you have allergies.
• Any other supplements, herbal products or over-the-counter medicines.
• Your repeat prescriptions, including pain relief, blood pressure medicines, antidepressants or sleeping aids.
• Whether the product appears on the Food Standards Agency novel food list, if you have checked.

A photograph of the label can be helpful, but a clear list is easier to pass between teams. If you use more than one product, record each one separately. If you have kept a dosage diary, bring the relevant pages rather than the whole notebook.

Questions worth putting to the team

The conversation should be practical, not apologetic. A simple opening works: I use a CBD product regularly. Here is the label and my record. I would like to know whether it affects the anaesthetic plan.

From there, consider asking:

• Should I pause the product before surgery, and if so, for how long?
• Should I take it on the morning of the operation?
• Could it interact with the anaesthetic, pain relief or other medicines I will be given?
• Do I need any blood tests, such as liver function tests, before the procedure?
• Will the recovery team need to know about it after surgery?
• If I use CBD for sleep or anxiety, what alternatives are sensible around the operation?
• When can I restart it afterwards, and does that change if I am prescribed painkillers?

Write the answers down. Pre-assessment appointments can be busy, and it is easy to forget a detail afterwards.

Raising it without turning it into a drama

Some people worry that mentioning CBD will delay surgery or prompt unwanted questions. In practice, the clinical team is used to discussing supplements, alcohol, smoking and recreational substances. The goal is a safe plan. If a clinician asks why you use CBD, a brief factual answer is enough. You do not need to justify your choice or present it as a treatment. You are supplying information, not seeking permission.

If you forget to mention it at pre-assessment, contact the hospital or surgical team before the operation. Do not wait until you are on the ward. A short call or message now is simpler than a surprise on the day.

A calm checklist before the consent form

Before the appointment, gather your product labels, dosage record and medicine list. Check whether the product is a food supplement or a prescribed medicine. Note your last dose and any other supplements. Decide on two or three questions you want answered. On the day, say clearly that you use CBD and hand over the record. Ask whether to continue, pause or stop, and follow the advice you are given. After surgery, ask before restarting, especially if your pain relief or other medicines have changed.

This is not medical advice, and individual circumstances vary. The central point is straightforward: planned surgery is a conversation, and CBD use belongs in it. Clear disclosure helps the anaesthetist and surgeon do their job, and it gives you a calmer basis for the decisions ahead.