• Chronic pain relief is a common reason individuals consider taking cannabis products(1).
  • One study showed that medical cannabis for chronic pain may be linked to reduced opiate use(2). Opiates are medications for pain relief(3).
  • Cannabinoid medications such as dronabinol and nabilone may help patients alleviate cancer chemotherapy-induced nausea and vomiting(4).
  • U.S. federal law prohibits using marijuana. However, depending on the state, individuals may use medical marijuana if they meet specific requirements and have qualifying conditions, such as chronic pain, epilepsy, or muscle spasms(5).

Are Cannabinoids Helpful in Treating Health Conditions?

Researchers have conducted various studies exploring the health effects and medical use of cannabis and cannabinoids that may help with certain health conditions.

However, many of these studies are inconclusive. Thus, there is no definite or concrete evidence that cannabinoids effectively treat such conditions.

Cannabinoids are chemical messengers that form part of the endocannabinoid system (ECS)(6). These molecules are categorized into exogenous and endogenous cannabinoids.

Exogenous cannabinoids are plant-based or synthetic cannabinoids, while endogenous cannabinoids (also called endocannabinoids) are naturally produced in the body.

Exogenous cannabinoids derived from Cannabis sativa, such as marijuana and hemp, may have the following effects on an individual’s body(7):

  • Cannabidiol (CBD): This cannabinoid may have potential anti-inflammatory, anticonvulsant, anxiolytic (antianxiety), analgesic (pain-relieving), and antioxidant benefits.
  • Tetrahydrocannabinol (THC): THC may provide anti-inflammatory, analgesic, and antioxidant benefits, although it may also produce a euphoric “high.”
  • Cannabigerol (CBG): This compound may provide antibiotic, antifungal, analgesic, and anti-inflammatory effects.
  • Cannabinol (CBN): CBN may have anticonvulsant, anti-inflammatory, and antioxidant benefits and may also produce sedative effects.
  • Cannabichromene (CBC): This cannabinoid may produce similar effects as CBG.
  • Tetrahydrocannabivarin (THCV): THCV is an anxiolytic compound that may produce a euphoric “high.”

On the other hand, endocannabinoids in the ECS comprise anandamide (AEA) and 2-arachidonoylglycerol (2-AG).

AEA provides an overall modulatory effect on an individual’s reward circuitry(8). This circuitry comprises a network of brain structures that regulate and control an individual’s ability to feel pleasure(9).

On the other hand, 2-AG regulates the individual’s circulatory system by affecting the body’s blood vessels and heart(10).

Although studies do not immediately conclude whether or not cannabinoids may help treat various medical conditions, scientists may utilize the findings to help with drug development.

Evidence: Can Cannabinoids Offer Any Benefits? How Do Cannabinoids Help?

Based on a study by the National Academies of Sciences, Engineering, and Medicine in Washington, D.C., cannabinoids may be effective antiemetics when administered to individuals with chemotherapy-induced vomiting and nausea(11).

The same study also suggested that cannabis or cannabinoid treatments may help with chronic pain, and oral cannabinoids may help improve patient-reported spasticity symptoms. Spasticity is abnormal muscle stiffness that interferes with movement.

To read more about this study, individuals may access the National Library of Medicine website under the National Institutes of Health(NIH) domain at www.ncbi.nlm.nih.gov.

Authors of one study conducted a systematic review and meta-analysis of cannabinoids for medical use. The authors determined the compounds’ adverse effects and effectiveness on disease-specific outcomes, daily living activities, global impression, and life quality(12).

Results showed that cannabinoids may have a better effect in managing chronic pain and spasticity when compared with a placebo.

Placebos are drugs comprising an inactive substance, such as sugar or starch, often used for comparing the effects of newly developed drugs(13).

The authors also noted that, despite having low-quality evidence, cannabinoids may be associated with improvements in sleep disorders, Tourette syndrome, and weight gain in human immunodeficiency virus (HIV) infection(14).

Post-traumatic Stress Disorder (PTSD)

PTSD is a disorder that happens to individuals who experience a traumatic situation, such as a dangerous or shocking event or the unexpected death of a loved one(15).

One study on the effects of nabilone, a synthetic cannabinoid medication, mentioned that this drug, administered in capsule form, may help provide relief to individuals experiencing PTSD(16).

The researchers noted that this synthetic cannabinoid may have a potential application as a clinically relevant remedy to help patients experiencing nightmares and a history of not responding to traditional therapies.


Researchers have limited scientific data suggesting cannabinoids may be ineffective in improving intraocular pressure associated with glaucoma(17).

Researchers explained that while these studies showed that cannabinoids may have positive effects, such benefits on intraocular pressure were short term only, indicating that cannabinoids may have a limited potential for glaucoma.

Glaucoma is a group of eye ailments caused by optic nerve damage, leading to vision loss and blindness(18).


Cancer-related anorexia-cachexia syndrome (CACS) is a debilitating disease that primarily presents as anorexia, weight loss, and muscle wasting (loss of muscle size)(19).

Researchers conducted a clinical trial comparing the effects of orally administered cannabis extract and delta-9-tetrahydrocannabinol (THC) on individuals with CACS(20).

Results showed that cannabis extract containing 1mg of CBD and 2.5mg of THC may be well tolerated among the participants with CACS.

However, there was no significant variance in the individual’s quality of life or appetite between the cannabis extract, THC, and placebo administered at the investigated doses.

Human Immunodeficiency Virus – Acquired Immunodeficiency Syndrome (HIV/AIDS)

Despite limited evidence, studies showed that cannabis and oral cannabinoid products may help increase appetite and minimize weight loss associated with HIV/AIDS(21).

HIV is a virus that targets an individual’s immune system(22). HIV can lead to AIDS if the virus is left untreated. Because HIV/AIDS has no cure, individuals who acquire this virus will have it for life.

Some regulatory authorities have registered dronabinol as a treatment for AIDS-based anorexia, and some jurisdictions have allowed the use of marijuana in patients with HIV/AIDS(23).

However, research is insufficient to conclude the safety and efficacy of cannabis and cannabinoids for medicinal use in this scenario.


In one study evaluating the effects of cannabinoids on psychosis, researchers conducted two random controlled trials on individuals with schizophrenia or schizophreniform psychosis(24).

The trials compared the effects of CBD, amisulpride (an antipsychotic drug), and placebo. In the first trial, researchers administered CBD with a maximum dose of 800mg. Meanwhile, the second trial used a maximum CBD dose of 600mg.

Results of the first trial showed no difference in effects on mental health between CBD and amisulpride. Meanwhile, the second trial showed no difference in effects on mood between CBD and placebo.

These results indicate insufficient evidence to conclude that CBD may be effective in helping with mental health outcomes associated with schizophrenia.

Schizophrenia is a chronic brain disorder often characterized by symptoms of hallucinations, delusions, thinking trouble, disorganized speech, and lack of motivation(25).

Parkinson’s Disease

One study analyzed the effects of CBD in patients diagnosed with Parkinson’s disease(26). Results suggested that CBD may help improve the quality of life of individuals with the disease, provided that they have no psychiatric comorbidities.

However, the researchers also mentioned that further studies utilizing larger samples and more specific objectives are required before drawing definitive conclusions.

Use of Cannabinoids for Pain, Cancer, and Autoimmune Diseases

Chronic pain relief is a common reason individuals consider cannabis products for medical purposes(27).

The study also mentioned that the use of cannabis or cannabinoids in adults with chronic pain may help reduce pain symptoms significantly.

One study showed that medical cannabis used for chronic pain may be associated with reduced opiate medication use(28). Using information from a survey of 244 individuals patronizing a medical cannabis dispensary in Michigan, the researchers said that medical cannabis use may be linked to a 64% decrease in opioid use.

Opiates are drugs used primarily for pain relief(29).

One review compiled 28 studies assessing the effects of various cannabinoid products on chronic pain(30). Cannabinoids used in these studies include nabiximols, smoked tetrahydrocannabinol (THC), nabilone, dronabinol, THC oromucosal sprays, oral THC, and vaporized cannabis.

Results suggested that improvements in pain measures were associated with cannabinoids, although most individual studies did not reach significant statistical outcomes.

Thus, the effectiveness of cannabinoids for managing chronic pain is still unclear, and researchers must conduct more extensive and welldesigned human clinical trials to improve the quality of the results.

Another study on the effects of smoked cannabis on chronic neuropathic pain showed that inhaling herbal cannabis containing THC may help reduce pain intensity and improve sleep(31).

Furthermore, despite controlled trials supporting cannabis’ potential to help manage pain, researchers still know little about the efficacy, dose, administration routes, and side effects of cannabis products(32).

Regarding cancer, one systematic review identified several preclinical studies on the antitumor effects of cannabinoids on gliomas (a tumor occurring in the spinal cord and brain)(33).

However, the authors mentioned that more clinical research is necessary due to the lack of sufficient evidence to make any statement regarding whether or not cannabinoids are effective for cancers, including gliomas.

Additionally, cannabinoid medications, such as dronabinol and nabilone, were approved in 1985 to help patients manage cancer chemotherapy-induced nausea and vomiting(34).

Cannabinoids may also help manage autoimmune diseases, such as rheumatoid arthritis or multiple sclerosis(35).

Rheumatoid arthritis is an illness wherein the immune system attacks the body’s joints(36).

On the other hand, multiple sclerosis occurs when the immune system attacks the protective coating surrounding the nerves, causing damage affecting the brain and spinal cord(37).

One study on the efficacy, safety, and tolerability of cannabinoids in managing rheumatic diseases, including rheumatoid arthritis, showed that cannabinoids may help provide pain relief and have therapeutic effects on sleep(38).

Despite these benefits, the shortterm controlled trials reviewed in the study had small sample sizes and were lacking in herbal cannabis studies, resulting in limited conclusions.

Another study analyzed the effects of Sativex on individuals with spasticity associated with multiple sclerosis(39). Results showed that the drug may help improve spasticity better than a placebo.

Are Cannabinoids Available as a Prescription Medicine?

Prescription medications containing cannabinoids include the following(40):

  • Dronabinol: This medication approved by the U.S. Food and Drug Administration (FDA) is a synthetic form of THC and is available as oral capsules (Marinol) or oral solutions (Syndros).

Individuals may take dronabinol for treating anorexia caused by AIDS-induced weight loss and nausea and vomiting caused by cancer chemotherapy.

  • Nabilone: Nabilone is a synthetic THC derivative available in oral capsule form (Cesamet). Nabilone is FDA-approved for treating vomiting and nausea associated with cancer chemotherapy.
  • Epidiolex: This drug is an FDA-approved plant-based oral CBD solution used for treating seizures associated with Dravet syndrome or Lennox-Gastaut syndrome in patients aged two years or older.
  • Nabiximols: This medication is a plant-based oromucosal spray (Sativex) containing a formulation of THC and CBD at a one-to-one ratio.

Adults may take nabiximols to help improve moderate to severe spasticity symptoms caused by multiple sclerosis.

In the case of dronabinol, nabilone, and nabiximols, healthcare providers can prescribe these drugs provided that the individual or patient failed to respond adequately to other conventional medications(41).

Why and How Are Cannabis-Based Products and Cannabinoids Therapeutic or Harmful?

Safety concerns involving cannabis and cannabinoids include the following(42):

  • Cannabis use may be associated with a high risk of motor vehicle crashes.
  • Smoking cannabis during pregnancy is associated with lower birth weight.
  • Using cannabis may lead to cannabis use disorder in some individuals. Symptoms include withdrawal, craving, lack of control, and adverse effects on professional and personal responsibilities.
  • Frequent use of cannabis has been connected to a higher likelihood of developing schizophrenia or other psychoses.
  • Marijuana may cause orthostatic hypotension (dizziness or head rush when standing), increasing fainting and fall risk.
  • Vaping products containing THC may be implicated in cases of lung injuries associated with vaping.
  • Children’s unintentional cannabis consumption, such as swallowing edibles like candies containing THC, may lead to severe illnesses that may require emergency room treatment or hospital admission.
  • Long-term cannabis users taking high doses may develop a condition that causes recurrent severe vomiting.
  • Some cannabis and cannabinoid products may be contaminated with microorganisms or pesticides.
  • Some cannabis and cannabinoid products may contain substantially different cannabinoid amounts from what was on the product labels.

Some individuals administer cannabis products through smoking or vaping. For example, consumers may use vape pens for vaporizing cannabis and inhaling the compound.

However, vapes (sometimes called vape pens or e-cigarettes) can cause health risks linked to lung disease, and many smokers still use both e-cigarettes and cigarettes(43).

Common diseases linked to smoking include lung cancer, coronary heart disease, and stroke(44).

Thus, consumers must exercise caution and be wary of these risks before considering vaping or smoking cannabis products.

Possible Side Effects

Common adverse effects of using cannabinoids include the following(45):

  • Dry mouth
  • Nausea or urge to vomit
  • Somnolence or drowsiness
  • Fatigue
  • Euphoria
  • Dizziness
  • Disorientation
  • Confusion
  • Loss of balance
  • Hallucination

Other side effects of cannabidiol (CBD) commonly reported include diarrhea, tiredness, and changes in appetite or body weight(46).

One study mentioned that some individuals taking prescription CBD oil may experience sedation and vivid dreams(47).

Drug Interactions

The increased recreational use of cannabis may significantly concern healthcare providers regarding unintended drug-drug interactions(48). These concerns arise because cannabinoid-containing products can interfere with the metabolism of numerous medications.

For example, particular drugs may inhibit or induce the activities of the cytochrome P450 enzyme group(49). Six of the more than 50 enzymes in this group metabolize around 90% of drugs.

U.S. federal law prohibits marijuana use. However, some states allow its medical use, especially for managing pain and nausea(50). In this case, individuals may qualify for medical marijuana treatment for the following reasons or conditions that may vary by state:

  • Alzheimer’s disease
  • Amyotrophic lateral sclerosis (ALS)
  • Chronic pain
  • Crohn’s disease
  • Epilepsy and seizures
  • Glaucoma
  • Muscle spasms and multiple sclerosis
  • Vomiting or nausea due to cancer treatment

The legality of CBD oil or medical marijuana use varies from one state to another. Before purchasing CBD products, consumers must review and understand their state’s CBD laws.

In 1996, California and Arizona were the first states to pass medicinal cannabis legislation, although Arizona rescinded the approval later(51).

The 2018 Farm Bill excludes hemp and hemp-based CBD products whose tetrahydrocannabinol (THC) concentration is no more than 0.3% from the Controlled Substances Act’s definition of “marijuana”(52).

Thus, under U.S. federal law, CBD products that exceed 0.3% THC content are considered illegal(53).

Cannabinoids and the FDA

The FDA advises that marketing CBD products as food additives or labeling them as dietary supplements is illegal(54). The agency also mentions that it has limited data on CBD’s safety and advises that consumers consider the real risks before using CBD.

In June 2020, the FDA approved Epidiolex, an oral medication containing a purified form of CBD(55).

According to the agency, Epidiolex is the only cannabis-derived CBD treatment for seizures linked to tuberous sclerosis complex (TSC) and two rare forms of childhood epilepsy: Lennox-Gastaut syndrome and Dravet syndrome.

Aside from Epidiolex, the FDA has approved dronabinol (Marinol, Syndros) and nabilone (Cesamet), which are synthetic cannabis products available as prescription medication from a licensed healthcare provider.

Another medicinal cannabis product is Sativex, an oromucosal spray containing 27mg of THC and 25mg of CBD(56).

Sativex, the brand name for nabiximols, is a herbal preparation extracted from the cannabis plant and contains CBD, THC, and other minor cannabinoids(57).

Individuals typically use this drug to help improve symptoms in adult patients experiencing moderate to severe spasticity caused by multiple sclerosis and who have not responded to other antispasticity medications(58).

As of 2021, the U.S. has not approved nabiximols, although the drug is approved in over 25 countries, including Canada, the United Kingdom, France, and Poland(59).

How the Endocannabinoid System Works

The endocannabinoid system (ECS) is an essential system that regulates and controls many of the body’s critical functions. These functions include the following(60):

  • Emotional processing
  • Learning and memory
  • Sleeping
  • Controlling temperature
  • Managing pain
  • Eating
  • Managing immune and inflammatory responses

Because of these functions, scientists are researching ways to develop drugs that may work with the ECS to help with various health conditions.

The ECS is a vast, system-wide network that comprises receptors and chemical signals throughout the body. In particular, the ECS contains two types of cannabinoid receptors, the CB1 and CB2 receptors.

CB1 receptors, mainly found within the brain and spinal cord, are also present throughout the body(61).

Specifically, CB1 receptors are located in the amygdala, a part of the brain affecting memory and emotional processing, and in the hypothalamus, which is involved in appetite regulation(62). Additionally, CB1 receptors in the nerve endings affect pain sensations.

On the other hand, CB2 receptors are present in the peripheral nervous system, specifically concentrated in immune cells(63). Activating these receptors produces an immune response that works to help reduce inflammation.

  1. Therapeutic Effects of Cannabis and Cannabinoids
  2. Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain
  3. Opiates
  4. Therapeutic Effects of Cannabis and Cannabinoids
  5. Medical Marijuana
  6. Cannabidiol Primer for Healthcare Professionals
  7. Ibid.
  8. Brain Activity of Anandamide: A Rewarding Bliss?
  9. The Reward Circuit: How the Brain Responds to Natural Rewards and Drugs
  10. Role of Endocannabinoid 2-Arachidonoylglycerol in the Physiology and Pathophysiology of the Cardiovascular System
  11. Therapeutic Effects of Cannabis and Cannabinoids
  12. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis
  13. Placebos
  14. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis
  15. Post-Traumatic Stress Disorder
  16. The Efficacy of Nabilone, a Synthetic Cannabinoid, in the Treatment of PTSD-Associated Nightmares: A Preliminary Randomized, Double-Blind, Placebo-Controlled Cross-Over Design Study
  17. Therapeutic Effects of Cannabis and Cannabinoids
  18. Glaucoma
  19. Cancer Anorexia – Cachexia Syndrome
  20. Comparison of Orally Administered Cannabis Extract and Delta-9-Tetrahydrocannabinol in Treating Patients With Cancer-Related Anorexia-Cachexia Syndrome: A Multicenter, Phase III, Randomized, Double-Blind, Placebo-Controlled Clinical Trial From the Cannabis-In-Cachexia-Study-Group
  21. Therapeutic Effects of Cannabis and Cannabinoids
  22. About HIV
  23. The Medical Use of Cannabis for Reducing Morbidity and Mortality in Patients With HIV/AIDS
  24. Therapeutic Effects of Cannabis and Cannabinoids
  25. What Is Schizophrenia?
  26. Effects of Cannabidiol in the Treatment of Patients With Parkinson’s Disease: An Exploratory Double-Blind Trial
  27. Therapeutic Effects of Cannabis and Cannabinoids
  28. Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain
  29. Opiates
  30. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis
  31. Smoked Cannabis for Chronic Neuropathic Pain: A Randomized Controlled Trial
  32. Therapeutic Effects of Cannabis and Cannabinoids
  33. Ibid.
  34. Ibid.
  35. Ibid.
  36. Autoimmune Diseases
  37. Ibid.
  38. Efficacy, Tolerability, and Safety of Cannabinoid Treatments in the Rheumatic Diseases: A Systematic Review of Randomized Controlled Trials
  39. Sativex(®) and Clinical-Neurophysiological Measures of Spasticity in Progressive Multiple Sclerosis
  40. Delta-9-Tetrahydrocannabinol and Cannabidiol Drug-Drug Interactions
  41. Ibid.
  42. Cannabis (Marijuana) and Cannabinoids: What You Need To Know
  43. Can Vaping Damage Your Lungs? What We Do (and Don’t) Know
  44. Health Effects of Cigarette Smoking
  45. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis
  46. Dosage, Efficacy and Safety of Cannabidiol Administration in Adults: A Systematic Review of Human Trials
  47. Cannabidiol Prescription in Clinical Practice: An Audit on the First 400 Patients in New Zealand
  48. Delta-9-Tetrahydrocannabinol and Cannabidiol Drug-Drug Interactions
  49. The Effect of Cytochrome P450 Metabolism on Drug Response, Interactions, and Adverse Effects
  50. Medical Marijuana
  51. Therapeutic Effects of Cannabis and Cannabinoids
  52. Hemp Production and the 2018 Farm Bill
  53. CBD & THC: Myths and Misconceptions
  54. What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD
  55. FDA Approves New Indication for Drug Containing an Active Ingredient Derived from Cannabis to Treat Seizures in Rare Genetic Disease
  56. Sativex Oromucosal Spray
  57. Nabiximols
  58. Sativex Oromucosal Spray
  59. Nabiximols
  60. The Endocannabinoid System: Essential and Mysterious
  61. Cannabidiol Primer for Healthcare Professionals
  62. Ibid.
  63. Ibid.
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