CBD Before Surgery: What Should You Tell Your Anesthesia Team?

At the pre-surgery visit, you are asked about the medicines you take. Many people think of CBD as "a natural product, not a medicine" and leave it off this list. Yet CBD can change how some medicines work and can cause drowsiness; this information helps the anesthesia team make the best plan for you. In this article we explain step by step what you should tell them, whether you need to stop CBD, and what the guideline recommends. For CBD's effect on pain after surgery: CBD for pain after surgery.

Why does it matter to mention CBD?

The surgical period is a time when many medicines are used together, such as anesthetics, painkillers, anti-nausea medicines and sometimes blood thinners. Every product you use becomes part of this picture.

• According to the ASRA 2023 guideline, the risk of a poor outcome around the time of surgery may be higher in patients who use cannabinoids (substances obtained from cannabis); that is why the guideline recommends asking every patient (the strongest level of recommendation).
• CBD can interact with blood thinners, some epilepsy medicines, organ transplant medicines and sedatives.
• Drowsiness can increase when it is used with opioids and sleep-inducing medicines.
• In people who use THC-containing products frequently, anesthetic doses may need to be adjusted, and pain after surgery may be harder to control.

That is also why the type of product matters. CBD (cannabidiol) does not cause intoxication or mental fogginess; THC, on the other hand, is the intoxicating substance in cannabis. Most of the guideline's recommendations on anesthetic dosing were written for people who use THC-containing products frequently; no human study has been reported showing that pure CBD changes anesthetic needs. Because products labeled "full-spectrum" may also contain THC, it helps to share the label information with your team.

What does the guideline say? Should I stop CBD before surgery?

• ASRA makes no recommendation either for or against routinely tapering cannabinoids before surgery, because there is not yet enough research on this. There is no set waiting period for CBD either.
• The guideline recommends that the possible risks of continuing use be explained to the patient. In other words, the decision is made based on your situation, together with your anesthesia team and the doctor who treats you.
• An approved (licensed) CBD medicine (used for severe types of epilepsy), like other epilepsy medicines, should not be stopped suddenly around the time of surgery; stopping it suddenly can increase seizures.
• There are no data on the safety of non-prescription CBD products around the time of surgery.
• The guideline recommends that the information be obtained by asking the patient and that it be recorded; it does not recommend routine drug testing of urine or blood.

Will the surgery be postponed?

According to the guideline, planned surgery should be postponed if there is a change in consciousness due to cannabis use; if marijuana or cannabis has been smoked, at least 2 hours should pass before surgery. No separate postponement rule has been written for pure CBD oil.

Possible risks: if I take a blood thinner

There are no human data showing that pure CBD directly increases bleeding during surgery. The risk arises through drug interactions: in a patient taking warfarin, the blood clotting value (INR) rose after CBD was started (Grayson 2018); the product information of the approved CBD medicine states that the effect of clopidogrel may be reduced. There are no direct data for apixaban and rivaroxaban. So if you use CBD together with a blood thinner, be sure to tell your surgeon and your anesthesia team.

What should you watch for after surgery?

• People who use cannabis products frequently should be told that pain after surgery may be harder to control (ASRA); people who use THC regularly should be monitored for withdrawal symptoms.
• When acetaminophen (paracetamol), which is often used after surgery, was taken together with high-dose CBD, rises in liver test values were seen more often (Pramhas 2023).
• Drowsiness and dizziness increase when taken with opioids, gabapentin or pregabalin; be careful about falls.
• THC-containing products have been linked to low blood pressure after surgery (Abdallah 2020).
• If you are thinking about restarting CBD after surgery, ask your team or pharmacist about it, taking into account the new medicines you are given at discharge (painkillers, blood thinners, antibiotics).

Details of studies that tried CBD for pain after surgery: Pain After Surgery and CBD.

If you use CBD: what should you tell the anesthesia team?

These questions are not asked to judge you but to make sure the surgery goes safely; you can talk about it openly. Going to the pre-surgery visit with the following information makes things easier:

1. Type of product: CBD oil (pure CBD, broad-spectrum or full-spectrum), a THC-containing product, or an approved medicine. Bring the package or a photo of the label; add the certificate of analysis if you have one (label reading).
2. How you take it: drops or capsules, food, cream, or products inhaled by vaping or smoking.
3. How much and how often: milligrams according to the label and how many times a day; how long you have been using it.
4. When you last took it: day and time.
5. Other medicines you take: especially blood thinners (warfarin, clopidogrel, apixaban, rivaroxaban), epilepsy medicines, antidepressants, sleep and anxiety medicines; alcohol use.
6. If you take an approved CBD medicine: also bring the name and advice of the doctor who prescribed it (often your neurologist); how to continue the medicine around the time of surgery is planned together.

At the visit, you can also ask: Should I keep using this product until surgery? Is there a risk with my blood thinner? Will my pain treatment after surgery need to change? Background on interactions with your medicines: drug interaction checker.

In Turkey: products obtained from cannabis, including CBD, can be sold only in pharmacies (Law No. 7557 and the regulation of January 31, 2026). Those in the medicine and health product category are dispensed with a prescription; the regulation states no prescription requirement for support products with a THC content of no more than 0.3%. As of October 2026, there is no approved (licensed) CBD medicine in Turkey. If you use a product you brought from abroad or bought outside a pharmacy, say so clearly too, because its contents are unknown. Details: CBD regulation in Turkey.

Conclusion

Adding CBD to your pre-surgery medicine list is a small but important step. The guideline recommends that every patient be asked about it and does not set a one-size-fits-all stopping time for CBD; the decision is made with your team based on your situation. Bringing your product, your dose and the time you last used it makes this conversation easier.

Frequently asked questions

References