Disclosure: BDI.ie is run by the team behind Dr. Hemp Me and CBD Éire. Where we mention those brands, we have a commercial interest. More about who we are.
Last reviewed: October 2026
If you take CBD and have an operation coming up, you may wonder whether it matters. It does. Your surgical and anaesthetic team need to know about every medicine and supplement you take, including CBD, so they can plan your care safely. This guide explains why, what the possible concerns are, and practical steps before and after surgery.
This is general information. Always follow the instructions from your own surgeon, anaesthetist and pre-assessment nurse.
The short answer
Tell your medical team you take CBD, how much and how often, and bring the product with you to your pre-operative assessment. Do not stop or start any supplement without their advice. Many teams ask patients to stop non-essential supplements for a period before surgery, often around one to two weeks, but the right timing depends on your operation, your health and your other medicines. Your team will tell you what applies to you.
Why CBD matters before surgery
Medicine interactions
CBD is broken down in the liver by enzymes (the cytochrome P450 family) that also process many medicines used around surgery, including some sedatives, painkillers and anti-sickness medicines. CBD may change how quickly these are cleared from the body. Your anaesthetist can take this into account if they know.
Drowsiness
CBD can cause drowsiness in some people. Combined with sedatives or strong painkillers, this could add to sleepiness after surgery.
Blood thinners
CBD can raise levels of some blood-thinning medicines, such as warfarin, which matters a lot before an operation where bleeding risk is managed carefully.
THC
Some products sold as CBD contain THC. Regular cannabis use is known to affect anaesthesia and pain control. If your product is not lab-tested, your team may need to treat it as cannabis use, so honesty helps them plan.
What to tell your pre-assessment team
- The product name and type (oil, capsules, gummies, cream).
- The strength and how much you take each day.
- How long you have been taking it.
- Why you take it.
- Any other supplements, herbal remedies or over-the-counter medicines.
- Any cannabis use, even occasional. Medical teams ask for safety, not to judge.
Bring the bottle or a photo of the label, and the lab report if you have it.
Common questions from patients
Will I be judged for taking CBD?
No. Medical teams routinely ask about supplements, alcohol and other substances so they can keep you safe.
Does CBD affect anaesthesia?
There is limited research on CBD supplements and anaesthesia specifically. Because of possible interactions and drowsiness, anaesthetists prefer to know and may ask you to stop beforehand.
Can I use a CBD cream before surgery?
Ask your team. You will usually be asked not to apply creams or lotions to the surgical area on the day of surgery.
After surgery
Do not restart CBD until your surgeon or GP says it is safe, especially if you have been prescribed painkillers, blood thinners or antibiotics. Follow your discharge plan for pain relief exactly. See our related guide to CBD and recovery after surgery.
Planned surgery checklist
- Write a full list of medicines and supplements, including CBD.
- Take it to your pre-assessment appointment.
- Ask: should I stop CBD, and when?
- Ask: when can I restart?
- Follow fasting and medication instructions exactly.
- Arrange someone to bring you home and stay with you if advised.
Dental procedures and minor surgery
Tell your dentist or doctor about CBD before procedures involving local anaesthetic or sedation too. The same interaction considerations apply, particularly if sedation or antibiotics are involved.
Emergency surgery
In an emergency, there is no time to stop supplements. Tell the team, or make sure someone with you can tell them, that you take CBD. Keeping a simple medicines list in your phone or wallet helps.
Choosing a CBD product you can describe accurately
If you use CBD, choose a product with a clear label and an independent lab report showing the CBD content and that THC is not detected. That makes it much easier to give your medical team accurate information. Our guide to choosing CBD oil in Ireland explains what to check.
Other supplements often paused before surgery
CBD is not the only supplement that matters. Medical teams commonly ask about, and may pause, supplements that can affect bleeding, blood pressure, blood sugar or sedation, such as:
- Fish oil and high-dose omega-3.
- Garlic, ginger and ginkgo supplements.
- Vitamin E at high doses.
- St John’s Wort, which interacts with many medicines.
- Valerian, kava and other “calming” herbs that may add to sedation.
- Ginseng and some weight-loss or energy products.
Bring everything to your pre-assessment so your team can review the full picture, not just one product.
What happens at a pre-assessment clinic
Most planned operations in Irish hospitals involve a pre-assessment appointment, in person or by phone, usually with a nurse and sometimes an anaesthetist. They check your health history, medicines, allergies, blood pressure and any tests you need, and give you instructions about fasting and which medicines to take or stop. This is the ideal time to mention CBD. If you are not offered a pre-assessment, phone the hospital or tell the anaesthetist on the day.
Preparing your body for surgery
The things that make the biggest difference to recovery are well established: stopping smoking and vaping as early as possible, cutting back on alcohol, staying as active as your condition allows, eating well with enough protein, and managing conditions such as diabetes or high blood pressure. Many hospitals call this “prehabilitation”. Ask your team what would help most before your operation.
Alcohol and recreational drugs
Be honest about alcohol and any recreational drug use, including cannabis. Regular heavy drinking and cannabis use can affect how much anaesthetic you need, pain control and withdrawal risk after surgery. The information is confidential and used only to keep you safe.
Keep a medicines list
A simple list on your phone or in your wallet, with every medicine and supplement, the dose and why you take it, is useful in any medical situation, not only surgery. Update it whenever something changes.
Day-surgery tips
For day procedures, you will usually go home the same day. Arrange for a responsible adult to collect you and, if advised, stay with you overnight. Do not drive, drink alcohol, sign legal documents or make major decisions for at least 24 hours after a general anaesthetic or sedation. Have your prescribed pain relief ready at home, and keep your CBD and any other supplements put away until you have been told it is safe to restart.
Questions to ask your anaesthetist
- Should I stop CBD before my operation, and how many days before?
- Are any of my other supplements a concern?
- Will CBD affect the anaesthetic or my pain relief?
- When is it safe to restart after surgery?
- Who should I contact if I have questions once I am home?
Writing your questions down before the appointment makes sure nothing is forgotten. Anaesthetists and pre-assessment nurses are used to these questions and would much rather you asked than guessed.
A note from us
BDI.ie is run by the team behind two Irish CBD brands. Even so, our advice is simple: your surgery is far more important than any supplement. Tell your team, follow their instructions, and only return to CBD once they agree it is safe.
Wishing you a smooth operation and recovery.
If anything is unclear, ring the hospital’s pre-assessment clinic.
Frequently asked questions
Should I stop taking CBD before surgery?
Ask your surgical or anaesthetic team. Many ask patients to stop non-essential supplements before surgery, often one to two weeks before, but follow your own team’s advice.
Does CBD interact with anaesthesia?
Research is limited, but CBD can affect liver enzymes that process some medicines used around surgery, and it can cause drowsiness.
Does CBD thin the blood?
CBD can raise levels of some blood thinners such as warfarin. Tell your team if you take any blood thinner.
Do I need to tell my surgeon I take CBD?
Yes. Tell them about all supplements, including CBD, so they can plan safely.
When can I restart CBD after surgery?
Only when your surgeon or GP says it is safe, particularly if you are taking new medicines.
Can CBD replace painkillers after surgery?
No. Follow the pain relief plan from your medical team.
What if my CBD product contains THC?
Tell your team. Cannabis use can affect anaesthesia and pain control.
Should I tell my dentist I take CBD?
Yes, especially before sedation or procedures with antibiotics.
Related guides
This guide is for general information only and is not medical advice. CBD products sold in Ireland are food supplements or cosmetics, not medicines. Speak to your GP or pharmacist before using CBD, especially if you take medication, are pregnant or breastfeeding.