Experts often recommend avoiding CBD and other cannabis products immediately before and after surgery. This recommendation is usually made due to insufficient research examining potential surgical risks.

Cannabidiol (CBD) is an active chemical found in cannabis that’s commonly taken to help reduce:

  • pain
  • nausea and vomiting
  • anxiety and stress

Research on the benefits and risks of CBD is still in the early stages. The only form of CBD that’s FDA approved is called Epidiolex used to treat seizures related to several rare epilepsy syndromes.

Researchers are still investigating how CBD and other cannabis products influence surgical outcomes. Some evidence suggests that people who smoke cannabis may require more anesthesia than those who do not use cannabis before surgery. However, little to no research has examined the effects of CBD on anesthesia.

Most medical experts recommend avoiding the use of cannabis products in the hours to days before surgery due to an unknown effect on surgical outcomes and unknown interactions with other medications or anesthesia.

Little research has been performed specifically looking at how CBD affects surgery. Researchers of one 2022 study showed that people who used cannabis before their procedure experienced the following effects more than those who did not:

  • higher postoperative pain scores
  • higher opioid use
  • more sleep disturbances

Effects of other cannabis products on surgery

Most of the current research examining the effects of cannabis products on surgery has focused on smoking cannabis, although this area is also currently under-researched.

The American Society of Anesthesiologists (ASA) recommends avoiding smoking cannabis on the day of surgery. They also recommend that doctors wait at least 2 hours after a person has last smoked cannabis to start elective surgery. This recommendation is based on evidence that:

  • Smoking cannabis may increase heart rate and blood pressure for at least up to 2 hours and may increase the risk of surgery-related heart attack.
  • Same-day smoking outside the 2-hour window may carry similar risks but to a smaller degree than smoking within 2 hours.
  • Smoking the day before surgery might have a negative impact, especially for people who smoke frequently.

The American Society of Regional Anesthesia and Pain Medication recommends that anesthesiologists screen all people for cannabis use before surgery.

CBD, medication, and anesthesia interactions

Researchers are still examining whether CBD interacts with other medications and whether any of these interactions may affect surgery. CBD is primarily broken down in your liver by the enzymes CYP3A4 and CYP2C19. CBD could theoretically interact with other medications that influence the function of these enzymes.

Some very early low quality research suggests a potential interaction between CBD and THC and blood-thinning medication warfarin. Increasing the effect of warfarin could theoretically put you at a higher risk of severe bleeding.

No guidelines have been established on whether it’s necessary to stop taking CBD before surgery and how long in advance you should stop taking CBD. To be safe, many experts recommend stopping it days in advance.

The American College of Surgeons recommends stopping cannabis products 72 hours before surgery.

The ASA recommends avoiding suddenly ceasing CBD-containing medication Epidiolex before surgery when used for seizure control.

The half-life of CBD is about 27 to 35 hours, meaning half of the medication is eliminated from your body in this period. A drug is often considered eliminated from your body after 4 to 5 half-lives. For CBD, this would correlate to about 4.5 to 7.3 days.

Levels of CBD in your blood past this period would likely be extremely low and unlikely to cause surgical problems.

It hasn’t been established whether it’s best to avoid CBD following surgery and how long you may need to avoid it. When in doubt, it’s always best to speak with your surgeon about their recommendations.

Research has been mixed on whether CBD might make a good pain-reliever for surgical pain.

In a small 2024 study published in the Orthopaedic Journal of Sports Medicine, researchers found that CBD taken for 14 days after surgery caused no difference in surgical outcomes than a placebo up to 1 year later. Researchers concluded that it may be a good option for reducing pain.

A task force initiated by the International Association for the Study on Pain found that current evidence doesn’t support the use of cannabinoids as pain relievers. Some evidence suggests that it might be more effective at treating chronic pain than acute pain resulting from surgery.

In a 2023 article published in The Journal of Pain, researchers argued that there’s no good reason to think CBD relieves pain effectively, but there’s good reason to doubt its efficiency and the purity of commercially available products.

Here are some frequently asked questions people have about CBD.

When should you tell your doctor about your CBD use?

Before your procedure, it’s a good idea to disclose to your anesthesiologist whether you’ve recently consumed any cannabis products. Knowing that you’ve recently consumed cannabis might influence your doctor’s anesthesia decisions.

Does CBD make you sedated?

CBD often induces feelings of relaxation. Although it may help you feel calm, it’s not a good idea to use it before surgery until more research comes out examining its safety before surgery.

Can you take CBD before a colonoscopy?

It’s best to speak with your doctor before taking CBD ahead of a colonoscopy so they can help you determine whether doing so is safe.

Can CBD help after surgery?

Anecdotally, some people find that CBD helps them manage pain after surgery. Research has yet to find that CBD makes an effective pain reliever after surgery.

A limited amount of research has examined the safety of CBD before and after surgery. It’s best to tell your surgeon in advance if you’re using any cannabis products so they can help you determine whether doing so is safe.

Theoretically, CBD could interact with other medications like warfarin, which could increase surgical complications. Some doctors also raise concerns that CBD products can be mislabeled or contaminated.