Marijuana & Surgery
It’s normal to feel nervous before going under for surgery. And medical marijuana might take the edge off. But there’s a reason you should hold off:
Marijuana use can add additional complexities to surgical procedures, may require additional sedation, and can affect postoperative pain management. Medical professionals recommend abstaining from marijuana before surgery. It’s also a good idea to let your doctors know about your cannabis history.
That’s the short version. Keep reading if you want more details. And if you are here just for the quick takeaway, you may still want to skim down to the end of the story for some advice on when to take a marijuana break before an upcoming procedure and why you should let your doctors know you use cannabis.
Problems with Smoking Marijuana Before Surgery
The American Society of Anesthesiologists lists several issues associated with marijuana use before surgery and offers this advice:
- Smoking marijuana can significantly increase heart rate and blood pressure within the first 2 hours following use, and may increase the patient’s risk of suffering a surgery-related heart attack.
- Same-day smoking of marijuana outside the two-hour window may still carry some risk, although the evidence is not as strong as for use within 2 hours.
- Smoking marijuana the day before surgery might have a negative impact, especially for someone who smokes it frequently.
- You may be advised to stop smoking marijuana one or more days before surgery unless you use it for a medical reason.
The American College of Surgeons adds another reason to forego that joint before surgery:
Smoked marijuana affects the airways, making it harder to place a breathing tube for anesthesia. Marijuana smoke also affects the lungs and can cause wheezing and coughing that could complicate anesthesia administration.
Which brings us to the most significant effect marijuana use has on surgical procedures.
Frequent marijuana users may require greater doses of inhaled and intravenous or anesthetics to achieve sedation during a surgical operation, and may need larger doses of local anesthetics during non-sedated procedures. While many cannabis users may not be aware of this phenomenon, it is increasingly common knowledge among anesthesiologists, and is well-documented in medical literature.
The good news is that a cannabis-induced need for additional anesthesia can be factored into the pre-treatment program if the medical team is informed of a patient’s use habits.
Regular Cannabis Use May Reduce Effectiveness of Local Anesthetics
A recent article in the Journal of Dermatological Treatment reported that a subject undergoing hair transplant surgery needed significantly greater than normal applications of lidocaine to manage pain during the implant procedure. During a follow-up assessment the patient revealed he used cannabis on a regular basis.
The authors wrote:
This case highlights how prolonged cannabis use can impact the effectiveness of local anesthetics and modify pain sensitivity during surgical procedures. The patient’s frequent requirement for additional anesthetic during the procedure indicate an altered pain threshold, which may have been exacerbated by cannabis withdrawal.
Cannabis Use May Elevate General Anesthesia Requirements During Surgery
The Journal of Clinical Anesthesia reported that cannabis use was associated with the need for higher doses of a common inhaled anesthetic (sevoflurane) to induce surgical sedation. Based on a scarcity of study data, however, the authors did not attempt to quantify the extent of this effect.
A small-scale Swedish study reported that cannabis users required higher dose of the intravenous anesthetic known as propofol to achieve the level of pre-surgery sedation needed to insert a laryngeal mask. On average, patients in the study who used cannabis more than once a week required a 20% higher initial dose of propofol than non-users.
Research published in the Journal of Osteopathic Medicine looked at how cannabis use affected three anesthetic agents commonly used for sedation during endoscopic procedures. Based on data from a sample of 250 patients in Colorado hospitals, the study found there was a moderate increase in the required dosage of fentanyl and midazolam, while the initial and ongoing doses of propofol needed to maintain sedation for the duration of procedures more than tripled.
The authors wrote:
Compared with non-users, cannabis users required 14% more fentanyl, 19.6% more midazolam, and 220.5% more propofol for the duration of the endoscopic procedure.
Researchers at Hadassah Hebrew University Hospital found that volunteers given a high-dose cannabis extract before being anesthetized for orthopedic surgery had a higher bispectral (BIS) index during sedation. The BIS index measures the patient’s depth of sedation, with 100 being fully awake, and 40 to 60 being the desired range of consciousness for surgery. The authors noted that in these cases a higher BIS number may not necessarily result in a heightened level of awareness, and may instead be related to other aspects of brain activity caused by marijuana’s stimulation of cannabinoid receptors.
In concluding remarks, the authors stated:
The clinical importance of this study is that with patients who use cannabis adjacent to general anesthesia induction, one cannot rely on BIS monitoring for the purpose of determining the patient’s sedative state.
In simple terms, this means that anesthesiologists may need to monitor additional indicators to ensure and maintain optimum levels of sedation when working with cannabis-using patients. This in turn points to the advantages of knowing the patient’s history of cannabis use, and underscores the importance of sharing this information with the treating physicians.
Cannabis May Help Stabilize Blood Pressure While Anesthetized
While recent marijuana intoxication may add complications to surgeries, long-term use without current intoxication may manifest beneficial effects. When under anesthesia during surgery, reduced blood flow can lead to organ damage, while elevated pressure can increase the risk of coronary events. Anesthesiologists carefully monitor blood pressure to ensure a stable blood flow. A study in Cannabis and Cannabinoid Research concluded that in cases of emergency surgeries, cannabis users exhibited fewer blood pressure related complications than non-users. The study authors suggested this phenomenon might be related to the ways in which cannabis influences CB1 receptors.
Cannabis & Post-Surgery Pain Management
Nearly half of all medical marijuana patients in Florida list pain management as a primary reason for cannabis therapies. However, there is evidence that these analgesic benefits may extend to post-surgical pain management. This effect has been noted in anecdotal case reports dating back more than a decade and in several recent observational studies.
A four-year analysis of patients recovering from major orthopedic surgery published in the journal, Anesthesia & Analgesia, found that patients with a history of marijuana reported higher pain scores and a poorer quality of sleep during the initial days of recovery. Most recently, findings from an large-scale study of patients receiving elective surgeries at the Cleveland Clinic showed that patients who had used marijuana within 30 days of procedures experienced higher levels of pain the following day, and took more opioids for pain management.
The authors stated:
Adult cannabis users undergoing surgeries were found to have significantly higher postoperative opioid consumption and pain scores than non-users.
This statement is not as dire as it might first appear however, because in research speak “significant” does not always mean “a lot more,” it just means that it is a phenomenon that cannot be explained away by random chance. In the case of this study, pain scores were 14% higher and opioid use was 7% greater. Significant, but not the drastic difference that would warrant an alarming headline.
The authors went on to report that cannabis use did not have “a clinically meaningful association with hypoxia or composite pulmonary complications.”
A follow-up study published in the Journal of Clinical Anesthesia in early 2026 found that increased postoperative pain was not a universal phenomenon among cannabis users, with roughly 1 in 3 patients reporting increased pain, with the remainder having little or no increase in pain as compared to non-cannabis users. The authors also noted some indications that after discharge from the hospitals, opioid use declined among cannabis users who resumed marijuana therapies.
When Should You Stop Marijuana Before Surgery?
Most sources now agree on the benefits of a 72-hour pre-surgery moratorium for smoked, vaped and edible cannabis products. While the most pronounced effects of cannabis peak and fade within 2 to 6 hours of use, the three-day mark is often cited as the point where residual cognitive and physical influences are minimized for most users.
While marijuana is not addictive in the same manner as tobacco, alcohol, or hard drugs like cocaine or heroin, regular users will sometimes experience withdrawal symptoms when they stop consuming cannabis. Common symptoms include agitated or aggressive behavior, heightened anxiety and sleep issues.
Harvard Health explains:
[Cannabis withdrawal] isn’t life-threatening or medically dangerous, but it certainly does exist. It makes absolute sense that there would be a withdrawal syndrome because, as is the case with many other medicines, if you use cannabis every day, the natural receptors by which cannabis works on the body “down-regulate,” or thin out, in response to chronic external stimulation.
Cannabis withdrawal symptoms typically manifest and peak within 24 to 48 hours of stopping marijuana use. There is speculation in the medical community that some of the post-surgery effects felt by cannabis users may be linked to the timing of withdrawal. A three-day break gives the body more time for these symptoms to abate before surgery and during post-surgery recovery.
Should You Tell Your Doctor About Marijuana Use?
Yes. Full disclosure is the way to go. The American Society of Anesthesiologists recommends that patients describe all medications and supplements being taken, including marijuana. Harvard Health contributor David Hepner, MD writes:
Because marijuana has a variety of effects on the body and on anesthesia medicines, it is crucial that anyone undergoing a preoperative evaluation disclose their marijuana use.
Adding:
Please don’t be afraid to disclose your use of marijuana to your physician, as it will not affect what we think of you. You will help us manage and adjust your anesthetic, prevent complications, and keep you as safe and healthy as possible.
This position is shared by CannaMD. Patients who have concerns about sharing this information can gain insights from our post on privacy issues as they apply to medical marijuana records.
Questions About Medical Cannabis & Surgery?
CannaMD‘s state-certified network of medical marijuana doctors is available to provide advice and assistance with all your medical marijuana questions and needs. Contact CannaMD‘s experienced team at (855) 420-9170 today.
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