• Studies showed that cannabidiol (CBD) may help relieve symptoms of anxiety disorders(1). Anxiety is a potential symptom of preoperative patients(2)
  • Research suggests that cannabinoids, including CBD, may provide therapeutic benefits for procedures such as orthopedic surgery(3).  
  • Studies suggest that CBD may produce severe drug interactions with blood thinners such as warfarin(4). Warfarin is an anticoagulant drug that patients may be required to discontinue before surgery(5).  
  • Before starting or continuing CBD preoperatively, it is highly recommended to consult a doctor.

How CBD Works When Taken Before Surgery 

Limited research has been conducted on CBD’s effects on preoperative patients. 

However, research suggests that CBD may exhibit anti-anxiety(6), antioxidative(7), and anti-inflammatory properties(8)

Patients preparing for surgical procedures can take measures to help attenuate pre-surgery anxiety(9)

Accumulating research on the involvement of the endocannabinoid system (ECS) in anxiety has produced novel therapeutic potential(10).  

The ECS is a complex signaling system consisting of cannabinoid receptors, cannabinoid-like molecules, and enzymes. 

Cannabinoid receptor 1 (CB1), which exists primarily in nerve cells, is significantly responsible for mediating the effects of cannabinoid binding in the human brain.  

CBD may exert various pharmacological effects, including antioxidant properties(11). This process involves CBD interacting with CB receptors.  

Additional research is warranted to investigate CBD’s potential to help reduce preoperative oxidative stress in individuals.

A 2021 study showed that cannabidiol and cannabigerol (CBG) may exhibit anti-inflammatory properties(12)

Additional research is warranted to investigate CBD’s purported anti-inflammatory properties in preoperative patients. 

How CBD May Help Relieve Anxiety Before Surgery 

Preoperative patients may experience anxiety(13). Symptoms and complications of anxiety disorders may include increased heart rate, gastrointestinal (GI) disorders, and sleep problems(14)

Anxiety may be associated with high blood pressure(15)

Researchers noted that a single dose of 600mg CBD reduced blood pressure (BP) in healthy subjects, according to a study published by JCI Insights(16). However, the compound increased the subjects’ heart rate (HR). 

Additional research is needed to decipher if CBD may help lower BP and HR in anxious preoperative patients

A panic attack may induce symptoms such as difficulty breathing(17)

An open airway allows air to flow in and out of the lungs efficiently. Anxiety and panic attacks may induce acute shortness of breath and affect normal breathing(18)

Furthermore, anxiety disorders may cause GI conditions(19)

The Current Neuropharmacology journal published a study showing that cannabinoids, including CBD, may help relieve symptoms of inflammatory bowel disease (IBD)(20)

Additional research is necessitated to determine if CBD may alleviate anxiety-induced GI disorders in preoperative patients. 

Furthermore, anxiety disorders may induce sleep disorders(21).

A 2019 study examined the potential therapeutic effects of CBD for anxiety and anxiety-related disorders(22). Most subjects received 25mg of CBD per day. The researchers noted that high-dose CBD improved sleep quality in 66.7% of subjects during the first month(23).  

Thus, CBD may possess potential as an alternative sleep aid by inducing sedative effects. 

However, further research is necessitated on the impact of CBD on preoperative patients with anxiety-induced sleep disorders. 

Consulting one’s doctor or other medical practitioners is advisable before initiating or continuing CBD use to prepare for surgery. 

Consuming CBD Products Before Surgery

Surgical patients may experience postoperative bleeding(24). An animal study published in the Phytomedicine journal showed that THC and cannabinol (CBN) may possess anticoagulant properties(25). CBN is a mildly psychoactive cannabinoid resulting from the breakdown of THC.

In this study, CBD induced no anticoagulant effects(26)

Anticoagulants help prevent the formation of gel-like clumps of blood known as blood clots.    

More human clinical trials are needed on whether CBD induces anticoagulant properties in preoperative patients.  

Individuals should consult their doctors regarding the management of postoperative anticoagulation with the best CBD oil. 

What Precisely Is Cannabidiol (CBD)? 

Cannabidiol is among the non-psychoactive constituents of the cannabis plant, unlike the psychoactive compound known as tetrahydrocannabinol (THC). THC produces a euphoric feeling associated with the use of marijuana.   

CBD products are typically sourced from hemp. Hemp plants are a variety of Cannabis sativa and differ from marijuana plants in their chemical and genetic compositions(27)

Popular CBD products on the market include oils, tinctures, edibles (gummies, chocolate bars, and cookies), topicals (creams, lotions, salves, and balms), and vape pens. 

The three primary types of CBD oil include:

Full-spectrum CBD oil: Contains all naturally occurring compounds in cannabis plants, including cannabinoids, terpenes, flavonoids, and essential oils. Terpenes are aromatic compounds, while flavonoids are plant metabolites.   

Broad-spectrum CBD oil: Like full-spectrum CBD oil, it contains numerous compounds. However, it is typically THC-free. 

CBD isolate oil: Isolates are pure CBD.

Talking to Doctors About Using CBD Oil Before Surgery

Consulting doctors before surgery is advisable to potentially lower how much CBD patients are taking. Such a measure can also help individuals determine if they should cease taking cannabidiol products altogether.  

Limited research has been conducted on CBD’s potential pre-surgical benefits. Doctors or other medical practitioners may require individuals to avoid taking medications, supplements, food, and beverages hours before surgery

Individuals using CBD a few days before their surgical procedure should inform their physician and anesthesiologist

Risks and Side Effects of CBD Before Surgery 

The World Health Organization (WHO) reported that CBD is generally well tolerated with a favorable safety profile(28).  

In 2018, the United States Food and Drug Administration (FDA) approved the CBD drug Epidiolex, a medication to treat seizures associated with rare forms of epilepsy(29)

Low doses of CBD are typically advisable before gradually increasing the dosage of products. 

In a CBD dosage review, researchers noted that a daily dose of 15mg of CBD per kilogram of the individual’s body weight was well tolerated(30)

Side effects of CBD are typically mild and may include reduced appetite, drowsiness, and diarrhea(31). 

Additionally, CBD may induce drug interactions(32). Cytochrome P450 enzymes help metabolize medications, although they may impact biological response to common drug classes(33).  

Consulting a physician or other medical practitioners, particularly those with experience in cannabidiol or medical cannabis, is advisable regarding the proper usage of CBD for preoperative preparations

CBD vs. Anesthetic Risks

When making preoperative preparations, patients should also consider the potential effects of CBD on intraoperative anesthesia. 

Anesthetic risk may be related to specific surgeries and unique medical issues. 

A recent animal study by the Baylor University Medical Center showed that THC and CBD displayed prolonged anesthetic duration(34).

Additional research on humans is warranted to determine CBD’s potential interactions with anesthetic methods, including local anesthesia. 

More research is necessitated to establish whether ceasing cannabis use at particular times before surgery increases anesthetic risk. 

Patients may converse with anesthesiologists about issues, including the amount of anesthesia used for their procedure and CBD’s potential interactions with anesthesia. 

CBD vs. Anticoagulant Risks

CBD is a cannabis-derived cannabinoid, while anticoagulants (blood thinners) are medications for preventing blood clots.

CBD may affect the blood-thinning level by competing with other medicines for liver enzymes’ metabolism of these drugs(35).

Individuals should consult a doctor before taking blood thinners with cannabis-related products, including CBD, before surgery.

Ingested CBD passes through the digestive system to the liver, where cytochrome P450 (CYP450) enzymes metabolize the substance.  

Liver enzymes CYP450 process approximately 60% of all medications(36). These medicines include warfarin and other blood thinners.  

Taking CBD with some pharmaceuticals broken down by the liver may increase the drug’s concentration and side effects(37)

Individuals taking prescription blood thinners should consult their doctor before beginning a CBD regimen.

Taking CBD simultaneously with other medications may cause serious complications due to drug interactions(38). These adverse effects may risk an individual’s health or wellbeing.   

When Should One Stop Taking CBD Before Surgery?

Patients may want to take CBD products as close to their surgical procedure as possible for therapeutic effects, including pain relief. Studies show that CBD may help provide chronic pain relief(39).  

Doctors may allow patients to take CBD up to the day of the surgery. However, research has indicated that blood thinners may produce interactions with CBD(40).  

Thus, it is advisable to cease using CBD sufficiently early enough to help minimize the risk of such drug interactions.

A medical study published in the Frontiers in Pharmacology journal suggested that the half-life of CBD is two to five days(41).

Half-life is the quantity of time required for a substance’s amount to decrease to half its original value(42).

When Is Resuming CBD Oil Safe After Surgery?

Following surgery, one may experience continued blood loss(43). Thus, one’s doctor may delay resuming CBD or cannabis use. Their potential anticoagulant properties may induce increased blood loss.  

Additionally, postoperative medications such as antibiotics(44) and morphine(45) may induce interactions with cannabinoids.  

Researchers have studied potential interactions between cannabinoids and opioid painkillers(46). For instance, vaporized cannabis may augment the analgesic effects of opioids.  

Further research is needed on potential interactions between CBD and postoperative pain medications.   

CBD purportedly may induce anti-inflammatory properties(47). However, the cannabinoid may produce mild side effects(48). Thus, recovering patients may opt to delay CBD use during their hospital stay or post-surgery recovery. 

Additionally, recovering patients may wish to start at a lower dose then gradually increase their CBD dosage.


  1. Cannabidiol as a Potential Treatment for Anxiety Disorders
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604171/
  2. What can help relieve anxiety before surgery?
    https://www.ncbi.nlm.nih.gov/books/NBK279557/
  3. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5470879/
  4. CBD and other medications: Proceed with caution
    https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743
  5. Warfarin Therapy – Management During Invasive Procedures and Surgery
    https://www2.gov.bc.ca/gov/content/health/practitioner-professional-resources/bc-guidelines/warfarin-during-surgery
  6. Cannabidiol as a Potential Treatment for Anxiety Disorders
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604171/
  7. Antioxidative and Anti-Inflammatory Properties of Cannabidiol
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023045/
  8. The anti-inflammatory effects of cannabidiol and cannabigerol alone, and in combination
    https://www.sciencedirect.com/science/article/abs/pii/S1094553921000596
  9. Preoperative Anxiety in Adult Patients Undergoing Day Care Surgery: Prevalence and Associated Factors
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6970311/
  10. The endocannabinoid system in anxiety, fear memory and habituation
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3267552/
  11. Antioxidative and Anti-Inflammatory Properties of Cannabidiol
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023045/
  12. The anti-inflammatory effects of cannabidiol and cannabigerol alone, and in combination
    https://www.sciencedirect.com/science/article/abs/pii/S1094553921000596
  13. What can help relieve anxiety before surgery?
    https://www.ncbi.nlm.nih.gov/books/NBK279557/
  14. Anxiety disorders
    https://www.mayoclinic.org/diseases-conditions/anxiety/symptoms-causes/syc-20350961
  15. Anxiety: A cause of high blood pressure?
    https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/expert-answers/anxiety/faq-20058549
  16. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5470879/
  17. Panic Disorder
    https://my.clevelandclinic.org/health/diseases/4451-panic-disorderShortness of breath
  18. Shortness of breath
    https://foundation.chestnet.org/lung-health-a-z/shortness-of-breath/
  19. Anxiety disorders
    https://www.mayoclinic.org/diseases-conditions/anxiety/symptoms-causes/syc-20350961
  20. Role of Cannabinoids in Gastrointestinal Mucosal Defense and Inflammation
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5333598/
  21. Sleep disorders
    https://adaa.org/understanding-anxiety/related-illnesses/sleep-disorders
  22. Cannabidiol in Anxiety and Sleep: A Large Case Series
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/
  23. Cannabidiol in Anxiety and Sleep: A Large Case Series
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/
  24. The management of postoperative bleeding
    https://pubmed.ncbi.nlm.nih.gov/16326202/
  25. Anticoagulant effects of a Cannabis extract in an obese rat model
    https://www.academia.edu/26963649/Anticoagulant_effects_of_a_Cannabis_extract_in_an_obese_rat_model
  26. Ibid.
  27. Defining Hemp: A Fact Sheet
    https://sgp.fas.org/crs/misc/R44742.pdf
  28. Cannabidiol (CBD) Critical Review Report
    https://www.who.int/medicines/access/controlled-substances/CannabidiolCriticalReview.pdf
  29. FDA Approves New Indication for Drug Containing an Active Ingredient Derived from Cannabis to Treat Seizures in Rare Genetic Disease
    https://www.fda.gov/news-events/press-announcements/fda-approves-new-indication-drug-containing-active-ingredient-derived-cannabis-treat-seizures-rare
  30. A systematic review of cannabidiol dosing in clinical populations
    https://doi.org/10.1111/bcp.14038
  31. What are the benefits of CBD–and is it safe to use?
    https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/is-cbd-safe-and-effective/faq-20446700
  32. CBD and other medications: Proceed with caution
    https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743
  33. The Effect of Cytochrome P450 Metabolism on Drug Response, Interactions, and Adverse Effects
    https://www.aafp.org/afp/2007/0801/p391.html
  34. A review of the anesthetic implications of marijuana use
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6650211/
  35. Cannabidiol (CBD)-what we know and what we don’t
    https://www.health.harvard.edu/blog/cannabidiol-cbd-what-we-know-and-what-we-dont-2018082414476
  36. The Role of CYP450 Drug Metabolism in Precision Cardio-Oncology
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014347/
  37. MedlinePlus. (2020, Jan 21). Cannabidiol
    https://medlineplus.gov/druginfo/natural/1439.htm
  38. CBD and other medications: Proceed with caution
    https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743
  39. A Balanced Approach for Cannabidiol Use in Chronic Pain
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7204604/
  40. What are the benefits of CBD — and is it safe to use?
    https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/is-cbd-safe-and-effective/faq-20446700
  41. A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6275223/
  42. It’s a question of physics: what’s meant by half-life?
    https://atomic.lindahall.org/what-is-meant-by-half-life.html
  43. What are some common postoperative discomforts?
    https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/after-surgery-discomforts-and-complications.
  44. Potential Adverse Drug Events and Drug–Drug Interactions with Medical and Consumer Cannabidiol (CBD) Use
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678684/
  45. Effects of coadministration of cannabinoids and morphine on nociceptive behaviour, brain monoamines and HPA axis activity in a rat model of persistent pain
    https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0953-816X.2004.03177.x?sid=nlm%3Apubmed
  46. Cannabinoid-opioid interaction in chronic pain
    https://pubmed.ncbi.nlm.nih.gov/22048225/
  47. Antioxidative and Anti-Inflammatory Properties of Cannabidiol
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023045/
  48. What are the benefits of CBD–and is it safe to use?
    https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/is-cbd-safe-and-effective/faq-20446700

 

CBD Clinicals is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more