The Risks of Mixing Weed and Opioids

2 min read · 6 sections
Evidence-Based Care
Expert Staff

The Effects of Marijuana

Marijuana contains tetrahydrocannabinol (THC), a psychoactive chemical that acts on specific cannabinoid receptors within areas of the brain associated with concentration, thinking, sensory and time perception, pleasure, memory, and coordination.1

THC over-activates these areas, resulting in a “high” that often includes: 

  • Happiness.
  • Lightheadedness.
  • Increased relaxation.
  • Sedation.
  • Increased sociability.
  • Enhanced sensory perception.

Marijuana also impairs cognitive functions such as attention, memory, and learning, and its use can produce other adverse side effects including reduced blood pressure, bloodshot eyes, increased heart rate, coughing, and increased appetite.2 

Take Our Marijuana Addiction Self-Assessment

Take our free, 5-minute marijuana addiction self-assessment below if you think you or someone you love might be struggling with a marijuana dependency. The evaluation consists of 10 yes or no questions that are intended to be used as an informational tool to assess the severity and probability of a marijuana use disorder. The test is free, confidential, and no personal information is needed to receive the result.

The Effects of Opioids

Common adverse side effects of opioid use include:3 

  • Dizziness.
  • Nausea.
  • Vomiting.
  • Constipation.
  • Respiratory depression. 

Opioids also have a high potential for physical dependence and abuse, which can lead to an increased risk of overdose and death. According to data from the Centers for Disease Control and Prevention, there were 47,600 drug overdose deaths involving opioids that occurred in the United States in 2017 alone.4

The Dangers of Mixing Marijuana and Opioids

Research has shown that the combination of marijuana and opioids can be therapeutic to some people suffering from chronic pain. In one study, individuals who smoked marijuana while being administered small doses of oxycodone experienced enhanced pain threshold and tolerance compared to the effects of taking oxycodone alone.5 

The synergistic effects obtained by combining these drugs can be very beneficial to patients as it would allow lower doses of opioids to provide pain relief, reducing the likelihood of prescription opioid addiction and overdoses. 

However, marijuana and opioids both have depressant effects, and when combined at nonmedical doses these drugs can suppress the central nervous system to dangerous levels.6 This can result in decreased brain function, low blood pressure, extreme sedation, coma, and death. 

Unfortunately, the combination of marijuana and opioids among recreational users is a common occurrence. One study found that 7 out of 10 teens who take prescription opioids for nonmedical reasons combine them with other drugs or alcohol, with marijuana being the most commonly co-ingested substance.7 

Studies have shown that the use of marijuana increases the abuse potential for opioids as well as other undesirable side effects. Analysis of data from the National Epidemiologic Survey on Alcohol and Related Conditions suggests that marijuana users are more than two and a half times more likely to misuse prescription opioids and develop prescription opioid use disorder compared to nonusers.8 

A recent study published in the Journal of Addiction Medicine also showed that combined use of opioid and marijuana was linked to greater symptoms of anxiety, depression, and substance use problems.9 

Treatment Options

If you or someone you love is suffering from the effects of polysubstance abuse involving opioids and marijuana, please contact a professional addiction rehab center today to learn about the treatment plans that fit into your specific needs. Due to the harmful symptoms associated with opioid withdrawal, a medical detox is often a critical first step in the recovery process. 

Detox can then be followed by a comprehensive addiction treatment program that will typically include various forms of therapy such as cognitive behavioral therapy.


  1. National institute on Drug Abuse. (2019). Marijuana.
  2. United States Drug Enforcement Administration. (2017). Marijuana/Cannabis. Drugs of Abuse: A DEA Resource Guide.
  3. Benyamin, R., Trescot, A.M., Datta, S., Buenaventura, R., Adlaka, R., Sehgal, N., Glaser, S.E., & Vallejo, R. (2008). Opioid complications and side effects. Pain Physician, 11(2 Suppl), S105-S120.
  4. Scholl, L., Seth, P., Kariisa, M., Wilson, N., & Baldwin, G. (2018). Drug and Opioid-Involved Overdose Deaths – United States, 2013-2017. Morbidity and Mortality Weekly Report, 67(5152), 1419-1427.
  5. Cooper, Z.D., Bedi, G., Ramesh, D., Balter, R., Comer, S.D., & Haney, M. (2018). Impact of co-administration of oxycodone and smoked cannabis on analgesia and abuse liability. Neuropsychopharmacology, 43(10), 2046-2055.
  6. Rogers, A.H., Bakhshaie, J., Buckner, J.D., Orr, M.F., Paulus, D.J., Ditre, J.W., & Zvolensky, M.J. (2019). Opioid and Cannabis Co-Use among Adults With Chronic Pain: Relations to Substance Misuse, Mental Health, and Pain Experience. Journal of Addiction Medicine, 13(4), 287-294.
  7. McCabe, S.E., West, B.T., Teter, C.J., & Boyd, C.J. (2012). Co-ingestion of prescription opioids and other drugs among high school seniors: results from a national study. Drug and Alcohol Dependence, 126(1-2), 65-70.
  8. Olfson, M., Wall, M.M., Liu, S.M., & Blanco, C. (2018). Cannabis Use and Risk of Prescription Opioid Use Disorder in the United States. The American Journal of Psychiatry, 175(1), 47-53.
  9. Rogers, A.H., Bakhshaie, J., Buckner, J.D., Orr, M.F., Paulus, D.J., Ditre, J.W., & Zvolensky, M.J. (2019). Opioid and Cannabis Co-Use among Adults With Chronic Pain: Relations to Substance Misuse, Mental Health, and Pain Experience. Journal of Addiction Medicine, 13(4), 287-294.
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