Posted By Dr. Eric Baron on Jul 21, 2020 |

Last updated on October 24th, 2020 at 01:10 am

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Medical marijuana (medical cannabis) for treatment of migraine, headache, pain, and chronic pain has become an increasingly hot topic of interest. As states continue to legalize the use of medical marijuana, there are increasing discussions and questions about its medical uses. What are the best medical marijuana strains for migraine, headache, and pain? Is medical marijuana helpful for migraine, chronic migraine, headache, pain, and chronic pain? How is medical marijuana used and dosed? Is medical marijuana legal to use? What are the side effects of medical marijuana? How do you get medical marijuana? How does marijuana differ from CBD (cannabidiol)? Patients ask about this type of treatment and many of these questions all the time, so this blog is to provide a comprehensive overview to answer all of these questions and much more. Reading the whole blog will give you a comprehensive, yet condensed detailed education of its history and everything you need to know about it, with an additional focus in the treatment of migraine and pain. Alternatively, you can skip down to find the specific topic that you are looking for information on.

When many people hear the term “medical marijuana”, they think of a street drug with no true medicinal qualities, used only for recreation and abuse. Their mind immediately activates the visual hippie imagery of the 1967 Summer of Love and 1969 Woodstock festival. However, this is an outdated view in the scientific research community. The term “marijuana” (sometimes spelled marihuana) is a loaded term with many negative connotations including old political and racial associations, and is associated with the plant being used recreationally as a drug of abuse. Cannabis is the scientific name of the plant and is the preferred terminology.

It is best to think of cannabis, as a broad class of medication. Within this medication class there are many types of cultivars (strains, breeds), or more accurately, chemovars (chemotypes). “Cultivar” is short for “cultivated variety”, while “chemovar” refers to “chemical variety”. The older cultivar classification system (Sativa, Indica, Ruderalis) has evolved to the more current, scientific, and simplified chemovar classification system. These systems are discussed in more detail further down under the treatment section.

Each chemovar has standardized reproducible compositions of cannabinoids and terpenes, which are the phytochemicals in cannabis that make up most of the medicinal qualities. The CBD and THC (tetrahydrocannabinol) cannabinoids and terpenes are discussed further down, and are also discussed in great detail here. Similar to a medication, there will be some variation in benefits, responses, effectiveness, and side effects between patients for each chemovar. Also similar to a medication, there are common characteristics attributed to each chemovar that the majority of users will experience.

For comparison of this concept, antidepressants are a broad class of medication. Within this medication class there are many types of drugs. Each drug has standardized reproducible compositions of neurotransmitter targets. Similarly, there will be some variation in benefits, responses, effectiveness, and side effects between patients for each drug, and a set of common characteristics attributed to each drug that the majority of users will experience.



To understand the current legal status of cannabis, it is important to know the history of cannabis, detailed here. The use of cannabis for medicinal purposes dates back to ancient times, with a Western/Central Asian botanical origin. Medicinal uses have been documented to 4000 BC or more. Chinese physicians were using it for joint pains and analgesia in childbirth 5000 years ago. Fast forward to 1839 when Dr. William Brooke O’Shaughnessy introduced the Western world to the medicinal uses of Cannabis indica, or “Indian hemp”, after he spent a professorship in Calcutta, India and learned of its uses while there. He advocated for its use in analgesia and muscle relaxation.

Throughout the 1800s into the 1900s, it was being recommended by many prominent physicians of those times for numerous diseases, particularly pain, headache, chronic daily headache, migraine, and chronic migraine, and was being used both acutely and preventatively.

In 1890, Sir John Reynolds, President of the British Medical Association, and Physician to the Royal household, wrote a paper in Lancet on his 30 years of experience prescribing cannabis for variety of ailments, particularly migraine and neuralgia.

In 1915, the “Father of modern medicine”, Sir William Osler, was recommending cannabis for migraine treatment in his historic medical textbook of those times, The Principles and Practice of Medicine. He went on to suggest that when treating migraine, “Cannabis indica is probably the most satisfactory remedy. Seguin recommends a prolonged course.” Dr. E.C. Seguin whom he referenced was a well-known neurologist and was the President of the NY Neurological Society. He was a vocal proponent of cannabis for migraine.

Cannabis-based preparations had been listed in the US Dispensatory in 1845. In North America, some pharmaceutical companies including Bristol-Meyers Squib, Parke-Davis, and Eli Lilly were producing cannabis-based preparations, as was Burroughs-Wellcome & Co. in England.

In the 1930s, Harry Anslinger was leading the Federal Bureau of Narcotics, which was essentially the early DEA. He began a campaign against cannabis, attempting to associate psychosis, mental deterioration, addiction, and violent crimes to cannabis use. He claimed cannabis was a drug of abuse used by minority and low-income communities. Instead of using the term cannabis when he was pushing his prohibition bill in front of congress in 1937, he purposely would use the term “marijuana,” subtly trying to convey a racial connection since it was commonly associated with recreational use among poor Mexican immigrants who would bring it from Mexico to the USA at that time. He reportedly chose his terminology wisely to fit this agenda and distance the plant from the more scientific term cannabis along with its growing uses for medicinal and industrial purposes. Furthermore, marijuana has a general connotation of being used as an intoxicant and recreationally, whereas cannabis has more of a scientific association. For all of these reasons, cannabis should really be the preferred terminology over marijuana.

The Marihuana Tax Act of 1937 was passed, attributing large fines and prison time to anyone involved with cannabis. Some historians also discuss influence on this law from prominent businessmen such as Andrew Mellon and the DuPont family since the hemp industry was gaining traction in industrial uses, posing a threat to synthetic and other more common competitor products, but that is a whole different discussion. The AMA (American Medical Association) strongly opposed this law.

In 1938, Dr. Robert Walton argued against the new Marihuana Tax Act and published a comprehensive review of cannabis, referencing 12 experts on its effectiveness for migraine.

In 1941 cannabis preparations were taken off the US Pharmacopoeia and National Formulary.

In 1942, Dr. Fishbein, the Editor of JAMA (Journal of the American Medical Association), published his recommendations for oral preparations of cannabis over ergotamine for menstrual migraine. Other physicians also published supporting evidence for cannabis in migraine treatment.

Then the 1960s hit, where there was a resurgence of recreational marijuana use. This left a lasting and ongoing negative stigma of cannabis. Again, cue the visual hippie imagery of the 1967 Summer of Love and 1969 Woodstock festival. Unfortunately, many people who are not aware of cannabis history have been stuck in this mindset since…

The final nail in the coffin for legal cannabis use came with the Controlled Substances Act of 1970. This is what changed cannabis to its schedule 1 drug illegal status, of which it has remained since that time. The Assistant Secretary of Health, Dr. Roger O. Egeberg, stated his reason as follows, “Since there is still a considerable void in our knowledge of the plant and effects of the active drug contained in it, our recommendation is that marijuana be retained within schedule 1 at least until the completion of certain studies now underway to resolve the issue.”

Well, we are well past those studies Dr. Egeberg mentioned, and extensively more have been completed since then, yet cannabis remains federally illegal, despite all the evidence and vast amount of knowledge that we have gained from research. Thus, it is only a matter of time until the tide finally turns completely, and cannabis is rescheduled from Schedule 1 in my opinion.

So, cannabis has been a schedule 1 drug since 1970. Schedule 1 drugs also include heroin, lysergic acid diethylamide (LSD), and 3,4-methylenedioxymethamphetamine (Ecstasy). According to the United States Drug Enforcement Agency (DEA), Schedule I drugs have a high potential for abuse, and have no accepted medical treatment use. If you are saying to yourself, that cannabis doesn’t seem like it fits into this category, you are certainly part of the majority opinion, which has shifted over the years. The DEA has continued to claim that cannabis has “no accepted medicinal use”, a statement which has no evidence to support it, but rather more evidence exists that disprove that claim.

Interestingly, despite this claim of no medicinal benefit, the US Government’s Department of Health and Human Services was awarded a patent (US Patent #6,630,507) for “cannabinoids as antioxidants and neuroprotectants” in 2003. Furthermore, the FDA has approved 3 synthetic versions of cannabinoids for medicinal purposes. Two are synthetic forms of THC (Dronabinol (Marinol), Nabilone (Cesamet)), and one is a purified form of CBD (Epidiolex). So, these statements and facts are clear contradictions to one another…

The schedule 1 classification has been a huge barrier preventing US federal funding for research and the legal ability to even proceed with research, although this has loosened up in recent years. This has historically been the primary hurdle in conducting medical research needed to obtain the evidence-based medicine in support of cannabis in the US. Meanwhile, many other countries such as Israel and Canada have been researching for years and have federal cannabis programs. For example, the Canadian equivalent to the US FDA is Health Canada. They have maintained a successful federal cannabis program for years. Despite this schedule 1 hurdle in the US, there has been accumulating evidence for various therapeutic benefits of cannabis, especially in the treatment of pain disorders.

In 1976, the FDA began an Investigational New Drug Program, after a glaucoma patient sued the government on grounds that cannabis was helping him, and won. This program closed in 1992, and 13 patients in the program at the time of closure were allowed to continue. Most recently, there were still 2 remaining who still receive monthly government supplied cannabis; one for multiple hereditary exostoses (painful bone tumor disorder), and the other for glaucoma. Access to this government supplied cannabis has since been controlled by the National Institute on Drug Abuse (NIDA), and the only federally approved cannabis source for decades has been from a farm at the University of Mississippi, who has had an ongoing contract with the federal government since 1968.

Through the 1990s-2000s, there was growing commentary from leading physicians and journals supporting cannabis for medicinal purposes. This has been accompanied by a growing push by medical organizations to reschedule cannabis to allow research and for patients who need it when they have failed all conventional treatments. Some of these organizations include American Academy of Neurology (AAN), American Medical Association (AMA), Epilepsy Foundation, American Journal of Public Health, and American Academy of Pediatrics (AAP).

In 2013, Dr. Sanjay Gupta MD, CNN Chief Medical Correspondent, issued a public apology article retracting his previous anti-marijuana stance which can be read here. He noted that “of more than 20,000 papers published in recent times, only 6% of the studies look at potential benefits of cannabis, while all the rest investigate potential harm, leading to an inherent bias and a profoundly distorted view.” He went on to further say:

“Well, I am here to apologize. I apologize because I didn’t look hard enough, until now. I didn’t look far enough. I didn’t review papers from smaller labs in other countries doing some remarkable research, and I was too dismissive of the loud chorus of legitimate patients whose symptoms improved on cannabis. Instead, I lumped them with the high-visibility malingerers, just looking to get high. I mistakenly believed the DEA listed marijuana as a Schedule 1 substance because of sound scientific proof. Surely, they must have quality reasoning as to why marijuana is in the category of the most dangerous drugs that have “no accepted medicinal use and a high potential for abuse.” They didn’t have the science to support that claim, and I now know that when it comes to marijuana neither of those things are true. It doesn’t have a high potential for abuse, and there are very legitimate medical applications. In fact, sometimes marijuana is the only thing that works. We have been terribly and systematically misled for nearly 70 years in the United States, and I apologize for my own role in that.”

Dr, Gupta has done a series of documentaries on CNN about the medicinal benefits of cannabis and are very enlightening to watch. This change in Dr. Gupta’s public opinion was also occurring along with spreading anecdotal cases of children with refractory pediatric epilepsy who were improving dramatically with CBD extracts from cannabis. One of these children, Charlotte Figi, became the poster child for this movement. In fact, the cannabis strain bred and extracted for high CBD for these purposes (Charlotte’s Web), was named after her. Unfortunately, she died 4/7/20 at the age of 13, and was remembered here.

The legal use of medicinal cannabis continues to increase globally, including the United States. In 1996, CA became the 1st state to pass the Compassionate Use Act, allowing the legal use of cannabis for medicinal purposes. Since that time, legalized cannabis has continued to grow. Medical use of cannabis is legal in 33 states (AK, AR, AZ, CA, CO, CT, DE, FL, HI, IL, LA, ME, MD, MA, MI, MN, MO, MT, ND, NH, NJ, NM, NY, NV, OH, OK, OR, PA, RI, UT, VT, WA, WV) + Washington DC. Recreational (“adult use”) is approved in 11 states (AK, CA, CO, IL, MA, ME, MI, NV, OR, VT, WA) + Washington DC. Despite a number of states legalizing cannabis use at the local level, it is still illegal federally in all states.

States which have medical cannabis programs have a list of qualifying conditions, which vary by state. The State Medical Board certifies doctors to “recommend” medical cannabis (Certificate to Recommend; CTR). The physician then confirms the qualifying condition and signs a “recommendation” form for potential benefit from medical cannabis. The patient then takes the recommendation to the local dispensary (which are also highly regulated by the state) and the patient discusses the best options there. However, it is important to remember that under the CSA (Controlled Substances Act), cannabis remains a schedule I drug, so doctors can’t “prescribe” cannabis. They can only “recommend” it. Also, interstate travel with any amount of cannabis or plant extract (including CBD products with THC content >0.3%) violates federal law and could potentially result in federal drug trafficking charges with stiff penalties of prison time and fines.

In 2009, the Justice Department sent a memorandum to federal prosecutors stating that patients and their providers should not face federal prosecution if they are following state law. In 2013 the Cole Memorandum was sent to US Attorney Generals, reinforcing that the Justice Department would not enforce federal prosecution in legal states who are following their state laws. In 2018, the Cole Memorandum was rescinded by Attorney General Jeff Sessions, which sent shockwaves through the industry. However, President Trump has continued to reinforce his support in protecting states that have legalized cannabis from federal prosecution. There have been discussions of re-evaluating the rescheduling of cannabis to remove the federal schedule 1 illegality, and it is suspected to be only a matter of time until this eventually happens.



In medical cannabis registries, the most commonly reported reason for cannabis use is chronic pain of various types. Because of the increasing evidence of cannabis in the treatment of pain, the Canadian Pain Society revised their consensus statement in 2014 to recommend cannabinoids as a third-level therapy for chronic neuropathic (nerve) pain based on the abundance of supporting evidence and a NNT (number needed to treat) estimated at approximately 3 (the number of patients needed to treat for 1 of them to receive benefit). In 2017, The U.S. National Academies of Sciences, Engineering, and Medicine published a statement that the use of cannabis for the treatment of pain is supported by well-controlled clinical trials and that there is substantial evidence that cannabis is an effective treatment for chronic pain in adults. In February 2019, the World Health Organization (WHO) recommended that cannabis be rescheduled and removed from the most restrictive scheduling category.

Cannabis works through our endocannabinoid system. The endocannabinoid system is a normal and important biological system within everyone which helps to maintain homeostasis. It plays a role in many regulatory physiological processes across all organ systems, and is widely distributed throughout the central nervous system (brain and spinal cord) and peripheral nervous system (nerves outside of the spinal canal). This system is involved in the “runner’s high” as well. Notably, it plays a very strong role in pain pathways. This system works by the interaction of our own natural endocannabinoids turning on or turning off various endocannabinoid receptors throughout our body.

Over 540 phytochemicals have been described in cannabis, 18 different chemical classes, and more than 100 different phytocannabinoids. THC and CBD have been the most researched and are considered the major cannabinoids. There are many additional cannabinoids referred to as minor cannabinoids. The quantities of major and minor cannabinoids are widely variable between different types of cannabis chemovars. There is evidence for analgesic and anti-inflammatory effects in many of the cannabinoids. Cannabinoids are unique to the cannabis plant, and can be thought of as the “plant equivalents” of our own endocannabinoids. So, they interact with the same endocannabinoid receptors in our body as our own endocannabinoids do. The existing literature and research on the treatment of pain have primarily studied cannabis itself with its variable and often undefined combinations of THC, CBD, other cannabinoids, terpenes, and other constituents. These compounds, especially cannabinoids and terpenes, play significant roles in influencing one another and working together. The synergy and interactions between these compounds are referred to as the “cannabis entourage effects”. Thus, the medicinal benefits of cannabis are suspected to be from the “entourage effects”, more so than any of the individual components alone.

THC is a major cannabinoid and the most researched in cannabis. THC causes the psychoactive qualities (“high”) of cannabis. THC has been shown to be 20 times more anti-inflammatory than aspirin and 2 times as anti-inflammatory as hydrocortisone. It is also a potent anti-emetic (anti-nausea), which is why there are two FDA-approved synthetic THC medications for chemotherapy related nausea and vomiting (Dronabinol, Nabilone). THC is the cannabinoid which is tested for in drug tests. It is important to know that most CBD products contain trace amounts of THC, although there are some varieties that do not. It is typically a negligible amount unlikely to show up on a drug test, but it is not completely risk free. You can read about the different types of CBD products here. THC can be detected by a variety of ways, although most commonly it is tested in the urine. Here are the general timeframes that it will show positive:

  • Blood:
    • Few hours to 1-2 days after a single use
    • In heavy users (multiple times a day), possibly up to a week
  • Saliva:
    • Appears in saliva an hour after use, detectable for up to 1-2 days
  • Urine:
    • 5-12 days after one-time use
    • 11-18 days when used 2-4 days/week
    • 33-48 days when used 5-6 days/week
    • Around 50-65 days if used daily (stored in adipose tissue)
  • Hair:
    • Generally 90 days, but some hair follicle tests can go back years

CBD is the other major cannabinoid and has gained a lot of attention as a therapeutic agent over the past several years given a wide range of reported anecdotal benefits. It is discussed in much greater detail here. In contrast to THC, CBD is non-intoxicating (no “high”). Furthermore, it helps to neutralize some of the negative THC side effects. CBD has been shown to be several hundred more times anti-inflammatory than aspirin. Greater than 65 molecular receptor targets and greater than 80 mechanisms of action have been identified. There have been scientific, animal models, and very limited human clinical trials documenting its anti-inflammatory and analgesic (pain-relieving) properties. However, there are no high-quality research studies to date evaluating isolated pure CBD in any pain, migraine, or other headache disorders. So, it is unclear how much benefit CBD in isolation provides outside of the presumed entourage effects that it contributes to.

In November 2017, The World Health Organization (WHO) concluded that CBD exhibits no evidence for abuse or dependence potential, and that there is no evidence of public health related problems associated with its use. In January 2018, the World Anti-Doping Agency (WADA) removed CBD from their prohibited list, no longer banning use by athletes. In December 2018, the Agriculture Improvement Act (Farm Bill) was signed into law. This legalized the agricultural growth and use of hemp (cannabis strains containing 0.3% THC or less) and hemp derivatives such as CBD. The Farm Bill also removed hemp from the Controlled Substances Act, making it no longer an illegal substance under federal law. Up until the Farm Bill was passed, any form of cannabis or cannabis derivatives (including CBD) have been federally illegal since the Controlled Substance Act of 1970. Therefore, it is important to remember that cannabis chemovars and CBD oils with greater than 0.3% THC are still illegal federally, require a medical cannabis card for use, and are illegal to cross state lines with. In May 2019, TSA began to allow travel with CBD products containing 0.3% or less of THC.

The terpenes account for many of the pharmacological properties of cannabis, as well as many medicinal herbs, plants and essential oils. They are the source of flavors, aromas, and other characteristics that help differentiate cannabis cultivars. Terpenes are often used in many household products such as limonene (citrus), pinene (pine, conifer), and linalool (lavender) to name just a few. Similar to the cannabinoids, many have anti-inflammatory and analgesic properties.



As discussed at the beginning of the blog above, there are many types of cannabis chemovars that vary widely in the composition of cannabinoids, terpenes, flavonoids, and other compounds. These components work synergistically to produce wide variations in benefits, side effects, and chemovar characteristics. Different chemovars have different ratios of these compounds, and thus have different characteristics.

The older cultivar (strain, breed) classification system was based on strain appearance, smell, and clinical effects. Cannabis Sativa strains were generally described by patients as uplifting, energetic, creative, euphoria, spacey, cerebrally-focused effects, and better for day use, while cannabis Indica strains were typically described as calming, relaxing, sedative, full body effects such as “body buzz”, and better for night use. Cannabis ruderalis (hemp) strains were considered predominantly or purely high CBD without any real clinical use effects.

However, biochemical studies of specific strain names often do not accurately distinguish CBD and THC content, which was the predominant basis for strain classification. Strain characteristics and clinical effects are dependent on varying ratios of major and minor cannabinoids and terpenes, not only from CBD:THC ratios, as there are no significant differences in CBD:THC ratios between many Sativa and Indica strains when studied chemically. Most strains used today are hybrid strains genetically cross-bred for standardized CBD, THC, terpenes, and minor cannabinoid content.

The older cultivar classification system has evolved to the newer and more scientific chemovar (chemotype) classification system, and is divided into type I-III chemovars. This system allows medical users to find a chemical profile better matching their pharmacological needs.

Type I chemovars are THC predominant. They are high THC (>0.3%, but generally >10-20%), and low CBD (<0.5%, but generally <2%). They are very intoxicating, and associated with recreational more than medical use. They are moderately-heavily psychedelic with changes in perception and sensory awareness and have the potential for significant physiological changes in heart rate and blood pressure. They can intensify relief from symptoms like nausea or pain, so terminal cancer patients may be one of the few true medical uses for these chemovars.

Type II chemovars are more balanced THC and CBD. They are high THC (>0.3%, but generally 3%-10%), and high CBD (>0.5%, but generally 1%- 14%). They are intoxicating to a lesser degree than Type I chemovars. They can be mildly-moderately psychedelic with milder cerebral and cognitive changes in perception and sensory awareness possible. In general, they can be more effective at treating symptoms with less negative side effects.

Type III chemovars are CBD predominant. They are low THC (<0.3%, but generally 0%-1%), and high CBD (>0.5%, but generally 5%-20% or more). They have low to no intoxication side effects. There is little to no cognitive impairment for most, but there can be possible mild effects in sensitive users, depending on the THC content.



                  The benefits of cannabis/cannabinoids in various chronic pain disorders has been well established. These benefits are suspected to likely extrapolate to headache disorders including migraine given overlapping neurobiological pathways of pain. There are some notable interactions and synergies between the cannabinoid receptors and pathways of migraine involving the trigeminovascular system (including the same receptors that the triptans work on) and serotonergic system. A more detailed discussion of this physiology can be read here and here. The medical literature regarding treatment of headache, migraine, and facial pain disorders shows limited supporting evidence for cannabis/cannabinoids in the treatment of chronic headaches, migraine including chronic migraine, medication overuse headache, cluster headache, idiopathic intracranial hypertension, and multiple sclerosis (MS) associated trigeminal neuralgia. However, the majority of this limited supporting evidence consists primarily of case series, case studies, case reports, surveys, clinical/anecdotal reports, and one retrospective analysis. There have been no placebo-controlled studies of cannabis for headache disorders or migraine thus far. There are only two prospective trials containing a control group evaluating the use of cannabinoids in the treatment of headache disorders, both of which showed benefit. The details and references of these studies and all of the smaller case studies mentioned can be read here and here.

Part of the difficulty in these types of trials, besides the federal illegality and the schedule 1 status of cannabis, is that there are so many variations of chemovars. It is unknown what chemovars and varieties of cannabis might be most helpful for migraine treatment. Most likely, it is not a one size fits all. Similar to how patients have a wide variety of therapeutic responses to abortive and preventive migraine treatments (what works for one person often does not work for another, etc.), responses to chemovars is probably similar. One person may respond very well to a specific chemovar, while another may respond better to a different one. Everyone is different, so like the trial and error process of trying different medications to see which may work best, cannabis chemovars most likely have a similar process.

With that said, there have been a couple studies evaluating a large medical cannabis registry, in an attempt to determine what chemovars patients with migraine and headache prefer to use. In one study, which can be read here, chemovars with high THC and low CBD were most preferred. “OG Shark” was the most preferred chemovar and consisted of high THC/THCA (tetrahydrocannabinolic acid) and low CBD/CBDA (cannabidiolic acid), with predominant terpenes β-caryophyllene and β-myrcene. This could reflect the potent analgesic, anti-inflammatory, and anti-emetic properties of THC, with anti-inflammatory and analgesic properties of β-caryophyllene and β-myrcene. Notably in that study, many headache patients replaced pharmaceuticals with cannabis, most commonly opiates/opioids (43.4% in headache patients, and up to 73% in chronic pain patients), anti-depressant/anti-anxiety (39%), NSAIDs (21%), triptans (8.1%), anticonvulsants (7.7%), muscle relaxers (7%), and ergots (0.4%).

In a follow up study (publication pending) 6 of the top 8 preferred chemovars were again high THC/low CBD, with “Headband” (22-24% THC, <1% CBD), “Warlock CBD” (8-11% THC, 8-11% CBD), and “Master Kush” (24-26% THC, <1% CBD) all tied for the top preferred cannabis chemovar. All three of these chemovars again had β-caryophyllene as one of their top 3 predominant terpenes, along with a mix of linalool, limonene, β-myrcene, bisabolol, and humulene as one of the top 3 predominant terpenes between them. There were 2 preferred chemovars which had high CBD and lower THC. They were “Warlock CBD” (8-11% THC, 8-11% CBD) which was in a 3-way tie for top preferred chemovar as mentioned above, and “Cannatonic” (3-7% THC, 6-10% CBD).



Cannabis can be used by smoked, vaporized, oral, oral-mucosal, topical, or rectal routes of administration. Oral routes cause a slower onset of action and a prolonged duration of action. Smoking and vaporizing cause the fastest onset of action and the shortest duration of action. Smoking is not recommended due to the production of unhealthy respiratory irritants and toxins. Vaporizing is a newer technique with a goal of suppressing irritating respiratory toxins by heating cannabis to a temperature where active cannabinoid vapors form, but below the point of combustion where smoke and associated respiratory toxins are produced.

Start low on the dose, go slow, and stay on as low of a dose as possible. This promotes tolerance to the THC psychoactive effects. Use the lowest dose THC possible, and use CBD and THC together because CBD helps to neutralize some of the negative THC side effects. Approximately 15-20% CBD with less than 1% THC is a good starting point to consider. CBD predominant preparations are better for working and daytime use, while THC predominant preparations are better for after work and at bedtime. Long acting oral formulations are better for chronic conditions and symptoms. Vaporization can be an as needed (prn) for episodic symptom exacerbations. Driving should be avoided for at least 4 hours after inhaled cannabis, 6 hours after ingested cannabis, and 8 hours if euphoria is experienced.

Common dosing quantities and terminology include one joint = 0.3-0.5 grams, one eighth = 3.5 grams, one quarter = 7 grams, and one ounce = 28 grams. Based on peer-reviewed literature, the majority of patients using smoked or orally ingested cannabis for medical purposes have been observed to use between approximately 10-20 grams of cannabis per week, 1-3 grams per day, and a frequency of 3-4 times daily. With that said, specific dosing recommendations are not available, and this is one area of much needed research in order to determine the best dosing for various disorders.

For THC dosing, 1-2.5 mg is a good starting dose. For example, starting at bedtime and increase 1-2.5 mg every few days at bedtime or daytime (depending on treatment goals) until benefits or side effects are reached. At 5 mg THC, many will experience benefit without excess side-effects. At 10 mg, most will have side effects. At 15 mg or more it may cause psychiatric side effects. As a loose reference, a 0.5-1 g cannabis cigarette may contain approximately 0.2-4.4 mg THC. However, THC content has gotten much higher in many chemovars over the years, so this can be much higher. The total daily THC dose should be less than 20-30 mg to limit adverse effects and tolerance. In addition, THC should preferably be used with CBD as mentioned above. Use of high dose THC chemovars more than 5 grams per day of flower suggests possible tolerance or misuse, and is usually unjustified medically unless perhaps an end stage cancer patient.

For CBD Dosing, starting at 5-20 mg/day divided once to three times daily, and titrating to effect is suggested. It is suspected that high doses are likely needed for pain and inflammation disorders, but this needs to be clarified with research. There are no established dosing guidelines or max doses established. For reference, doses of 400-600 mg/day showed benefit in anxiety, doses of 600-800 mg/day showed benefit in psychosis, and doses up to 2500 mg/day (25-50 mg/kg) have been used in epilepsy studies.



Side effects are influenced by dose, method of administration, patient tolerance, chemovar of cannabis, ratios of THC to CBD, cannabinoids, terpenes, production quality control (toxins, fungus, bacteria, heavy metals, etc.) to name a few. Many studies have been inconclusive or contradictory in terms of association with stroke, heart attack. This publication provides the most comprehensive review of cannabis and its recognized side effects. The most common side effects (which vary depending on the chemovar) include dizziness, dry mouth, increased appetite, disturbances in concentration, and sedation/drowsiness. Less common side effects can include incoordination, euphoria, anxiety, and paranoid thinking. In the majority of trials, side effects have been well tolerated, mild to moderate, transient, and not bothersome enough that many patients withdrew from studies. Overdose can occur and is typically from high THC content and oral dosing. Signs may include tachycardia, arrhythmia, confusion, panic attack, extreme paranoia, and hallucinations.

From existing research, there is concern for possible long-term cognitive side effects of cannabis use during adolescent years when the brain is still rewiring, pruning, and organizing itself. Studies suggest a decline in IQ/neurocognitive function when used frequently under age 18. In adults, a larger study suggested problems in verbal memory recall after chronic cumulative use (after 5 years of cumulative frequent/chronic use, 1 in 2 people may recall 1 word less from a list of 15 words). Current users had both decreased verbal memory and processing speed.

According to “The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research”, published by the National Academies of Sciences, Engineering, and Medicine in January 2017, the following are conclusions regarding cannabis side effects based on existing literature reviews.

For cardiovascular risk, there is limited evidence of cannabis triggering an acute MI (heart attack), ischemic stroke, or subarachnoid hemorrhage. There is no evidence to support or refute chronic cannabis use and increased risk of acute MI.

For cancer risk, there is moderate evidence of no association between the incidence of lung cancer (cannabis smoking), or the incidence of head and neck cancers. There is no or insufficient evidence to support associations with other cancers.

For respiratory disease risk, there is substantial evidence for worse respiratory symptoms and more frequent chronic bronchitis episodes (long-term cannabis smoking).

For neurocognitive risk, there is moderate evidence of impairment in the cognitive domains of learning, memory, and attention with acute cannabis use, but limited evidence for persistent impairments in cognitive domains of learning, memory, and attention after sustained cannabis abstinence.

For mental health risk, there is substantial evidence for development of schizophrenia or other psychoses in those at risk genetically, with the highest risk among the most frequent users. There is moderate evidence for increased symptoms of mania and hypomania in bipolar disorder. There is a small increased risk of depressive disorders and an increased incidence of social anxiety disorder. There is an increased incidence of suicidal ideation and suicide attempts with higher incidence in heavier users, and an increased incidence of suicide completion.

For prenatal, perinatal, and neonatal exposure, there is substantial evidence between maternal cannabis smoking and lower birth weight. During lactation, the amount reaching the infant is very low, although the effects of this are unknown. Therefore, it is recommended to not use cannabis in either pregnancy or breastfeeding.

There is substantial evidence for an increased risk of motor vehicle crashes. There is moderate evidence for increased risk of overdose, especially among pediatric populations. There is no or insufficient evidence for all-cause mortality, and there has been no documented death exclusively attributed to cannabis overdose or use. Cannabis has been shown in toxicology studies to be 114 times less lethal than alcohol. In fact, the deadliest substances in one toxicology study in order were alcohol, heroin, cocaine, tobacco, ecstasy, methamphetamine, and lastly, cannabis.



Cannabis hyperemesis syndrome (CHS) has become increasingly seen as states legalize cannabis. It presents with clinical symptoms of cyclical nausea/vomiting, diffuse abdominal pain, and the need to take frequent hot showers (this is a pathognomonic sign).

Episodes of these symptoms last 24-48 hours, may last 7-10 days, and often recur with re-exposure of cannabis. CHS tends to be associated with high-dose, high-THC regular cannabis use. It can be confused with CVS (cyclical vomiting syndrome), and is differentiated by a history of chronic cannabis use and frequent hot bathing which produces temporary relief. The etiology (cause) of CHS is not fully understood. It has been theorized that there is a dysregulation of the endogenous cannabinoid system by downregulation of CB1 (cannabinoid 1) receptors, and in the GI (gastrointestinal) tract this may slow gastric motility, causing hyperemesis. Genetic differences in the cytochrome P450 system (enzymes in the liver which metabolize drugs) has also been proposed. The TRPV1 receptor in our bodies interacts with the endocannabinoid system. More specifically, anandamide (our main natural endocannabinoid) works at this receptor (one of many). Interestingly, this receptor is also the capsaicin receptor, and is activated by heat such as in hot peppers (which contain capsaicin). Therefore, it has also been proposed that perhaps the fact that these patients take frequent hot showers/baths for relief is because they are indirectly activating their endocannabinoid system.

Treatment of CHS revolves around cannabis cessation. There is no way around it. Supportive therapy can assist with fluid resuscitation. Capsaicin 0.075% topically to areas of the abdomen, back of arms, and areas that hot water gives symptom relief have shown some benefit (not using on private areas or mucosal surfaces). Antipsychotics such as Haloperidol and Olanzapine showed some temporary benefit. Conventional antiemetics, antihistamines, serotonin antagonists, benzodiazepines have shown limited evidence for effectiveness, and opiates should be avoided.



Comparative addiction rates between substances have included tobacco 32%, heroin 23%, cocaine 17%, alcohol 15%, and lastly cannabis 9% (but 17% when used in adolescence, and 25-50% in adolescents who are using daily). Tolerance develops much faster with high potency high THC chemovars.

The DSM-5 recognizes 5 cannabis-associated disorders:

-Cannabis Use Disorder

-Cannabis Intoxication

-Cannabis Withdrawal

-Other Cannabis-Induced Disorders (Cannabis Intoxication Delirium, Cannabis Induced Psychotic Disorder, Cannabis Induced Anxiety Disorder, Cannabis Induced Sleep Disorder

-Unspecified Cannabis-Related Disorder

An estimated 3-4% of users meet criteria for Cannabis Use Disorder. The prevalence decreases with age, with the highest ages 18-29 years old (4.4%), and lowest ages 65 and older (0.01%). Cannabis Use Disorder is divided into mild (2-3 criteria), moderate (4-6 criteria), and severe (7 or more criteria). These criteria include any of the following:

  • Cravings and urges to use cannabis
  • Failure to fulfill major role obligations (work, school or home)
  • Unsuccessful attempts to quit/cut down
  • Spends excessive time in acquisition, using or recovering from use
  • Using Cannabis in larger amounts or for longer than you meant to (tolerance)
  • Continued use despite consistent social or interpersonal problems
  • Recurrent use in hazardous situations
  • Important social, occupational, or recreational activities are given up or reduced because of cannabis use
  • Needing more cannabis to get the effect you want (Tolerance)
  • Uses despite negative effects (physical or psychological)
  • Development of withdrawal symptoms, which can be relieved by taking more of the substance






Author: Dr. Eric Baron