THCA is the main cannabinoid found in large amounts in raw unheated cannabis flower. When this compound is exposed to heat (about 230°-300°F) it is converted to THC by a process called decarboxylation. THCA is not psychoactive. Studies show that THCA is a potent anti-inflammatory. Other medicinal properties include antispasmodic, anti-tumor and anticonvulsant. Additionally, THCA blocks anticipatory nausea (a type of conditioned nausea that occurs when a person who has terrible nausea from chemotherapy develops nausea upon thinking about the future chemo treatment).
A number of my patients are using THCA successfully for inflammatory conditions and for seizure disorders. Some also find relief from pain, including nerve pain, which is notoriously difficult to treat. Some patients have reported excellent results from regularly drinking juices made from raw cannabis flowers and leaves. This method of taking THCA is challenging, as a large number of plants are required to regularly juice fresh leaves. Fortunately, THCA-rich sublingual cannabis tinctures and oils have become available over the past few years.
CBDA is the precursor cannabinoid to CBD and is found in the unheated raw cannabis flower. Heating of CBDA converts it to CBD. CBDA is non-psychoactive. Only a few scientific studies have researched the medicinal effects of CBDA. CBDA combats nausea in multiple animal studies. CBDA has been shown to be a selective cyclooxygenase-2 (COX-2) inhibitor – this means it blocks the production of a compound we make in our bodies called prostaglandin. Prostaglandin is responsible for causing pain and swelling associated with inflammation. There is only one pharmaceutical COX-2 inhibitor available in the US (called celecoxib, brand name Celebrex) and it has side effects that include heart attack, stroke and intestinal ulcers. CBDA, taken by ingesting the juice made from a CBDA-rich cannabis plant or by a cold extracted oil, could potentially substitute for this pharmaceutical. CBDA has also been found in one laboratory study to act as an inhibitor of breast cancer cell migration, meaning it blocked the spread of aggressive breast cancer cells. This study showed that CBDA turns on a chemical compound that inhibits cancer cell mobility. A small number of suppliers have begun carrying cannabis oils rich in CBDA.
THCV is another plant cannabinoid that has beneficial medicinal effects. At low doses, THCV is a neutral antagonist of the Type 1 cannabinoid receptor, meaning it binds to the receptor, causing no effect on its own, while blocking other compounds from acting on the receptor. At higher doses it binds to and activates the Type 1 cannabinoid receptor. However, patients who have used chemovars that are high in THCV have reported its effects to include appetite suppression, anti-anxiety, anticonvulsant, tremor reduction and pain relief. THCV is reported to be psychoactive but in a recent study, participants who received THCV could not distinguish it from a placebo. In the same study, subjects reported that when given both THCV and THC together, the effects of THC were weaker or less intense. THCV is being investigated as an “anti-obesity” agent as it suppresses appetite and has been suggested as an excellent choice for those suffering with PTSD due to its ability to block panic attacks. It has also been recommended for treatment of tremors related to Parkinson’s disease. Cannabis varieties reported to have higher amounts of THCV are currently quite rare and may include Malawi Gold, Doug’s Varin, and Durban Poison.
Cannabidivarin is a non-psychoactive cannabinoid that has been shown in numerous animal studies to work as an anticonvulsant by itself and additively when combined with CBD. It is well tolerated in an initial clinical trial for adult epilepsy in Europe and currently is in the early stages of research for its effectiveness and proper dosing for both adult and pediatric epilepsy.
Cannabis chemovars and products can and should be tested so patients can be assured of the quality of their medicine. Cannabis testing includes the following information:
Sample 1 shows test results for a product that is THC rich (18%) and almost devoid of CBD (0.3%). The CBN content is 0%, which reflects that this test was performed shortly after the flower was harvested. With very little CBD, this product will have dominant THC effects and significant psychoactivity for most (depending on the user’s tolerance to THC). Medicinal effects include pain relief, reduced anxiety and depression, relief from nausea and vomiting, enhanced appetite, and lowered intraocular pressure. Importantly there were no pesticides, solvents or mold detected in this sample.
Sample 2 shows test results for a product that is quite different than Sample 1. Since the CBD content is quite high at 18% and the THC content is very low (0.6%), this chemovar will have dominant CBD effects, such as pain relief, lessened anxiety and depression, anti-convulsant and anti-inflammatory effects without psychoactivity. You can determine the CBD:THC ratio by dividing the percent of CBD by the percent THC: 18% divided by 0.6% results in a ratio of 30 parts CBD to 1 part THC (more on this later in the chapter). Again it is important to note that no pesticides, solvents or mold were found when the product was tested.
Sample 3 shows test results for a product that has almost equal amounts of CBD and THC. The CBD will mitigate some of the THC effects and result in less psychoactivity; however, some of the effects of this chemovar will depend on the user’s previous experience with cannabis. A person who uses cannabis on a regular basis would likely have less psychoactivity than someone who is inexperienced or new to cannabis use. This chemovar has the medicinal effects of pain relief, relief from nausea and vomiting, lessened anxiety and depression, anti-inflammatory and may be anti-convulsant for some.
As you can see, the cannabis plant is very diverse in its expression of CBD and THC. Most patients have to try a number of different products that contain different CBD and THC amounts to find what works best for their particular medical condition.
Here are examples of terpenoid tests on two different cannabis chemovars:
Chemovar 1: Terpenoid Profile in milligrams per milliliter (mg/ml)
Chemovar 2: Terpenoid Profile in milligrams per milliliter (mg/ml)
If you compare the two test results, you can see they have different terpenoid profiles. Chemovar 1 contains β-caryophyllene (anti-inflammatory, pain relief, intestinal relief), pinene (anti-inflammatory, focus and memory enhancer) and linalool (anti-anxiety, pain relief) as its three most common terpenoids. The β-myrcene content is not detected (ND) and therefore this chemovar is likely to not be sedating.
Chemovar 2 contains a large amount of β-myrcene (sedating, analgesic) with some pinene and β-caryophyllene, both of which are anti-inflammatory. This chemovar is likely to be sedating with some pain relieving properties.
Solvents are often employed in the manufacturing of cannabis extracts and concentrated preparations. Solvents that are not purged properly and leftover in the end product are called “residual solvents.” Butane, propane, pentane, hexane, and naphtha, all of which are petroleum derivatives, highly flammable and potentially carcinogenic, are being used by some suppliers to make concentrates and extracts.
Although some cannabis experts claim that professional butane extraction is safe and results in a clean product, the majority of butane-processed extracts are being made by laypersons, not chemists, who are not operating within a laboratory setting. The result can be a product that contains residual solvent.
Additionally, the final products made with these compounds often have lower levels of terpenoids, which can decrease the medicinal benefits for some patients. I do not recommend products made with these chemicals, unless testing by a reputable lab reveals no residual solvent.
Ethanol is also used as a solvent for concentrates and extracts. Ethanol is safe for consumption by adults and the final products often have high terpene content. However, a process called supercritical carbon dioxide (CO2) extraction is becoming quite popular as no harmful solvents are used and the end product is solvent-less. CO2 extraction is considered by many to be the cleanest and most safe extraction method. CO2 extraction may result in excellent terpenoid content when compared to butane extraction although many believe the latter to be superior. No matter what process is used, all concentrates and extracts should be tested for residual solvents so patients can be assured of the purity of the product.
Residual solvent amounts are often expressed in parts per million (ppm). For example, the state of Colorado requires testing of all concentrates and extracts with butane and propane residual solvent levels to be less than 50 ppm, and heptane, isopropranol and ethanol levels to be less than 10 ppm.
A few years ago, a mother brought her son to see me for severe symptoms related to autism. She brought a syringe containing concentrated cannabis oil that her neighbor had made and given to her. She had not used the oil, as she was nervous about using cannabis without talking to a physician first. I insisted that the product be tested for potency, residual solvent, pesticides, mold and bacteria before use. The oil was found to contain 94,000 parts per million isopropanol. This is over 9,000 times the permissible level allowed in Colorado!
Isopropanol and its metabolite acetone have been shown to cause central nervous system depression, nausea, vomiting, dizziness, respiratory depression and coma. This is an all too common example of non-chemists manufacturing cannabis products with the potential to make people sick. It is imperative that patients only use tested cannabis products!
Cannabis can be contaminated with bacteria or fungi (yeast or mold) at any point in the growing or product manufacturing process. Contaminated cannabis can be dangerous, especially for those with compromised immune function. Bacteria and mold can be identified by using plating, whereby prepared samples are placed on growth medium and incubated; any growth is counted and reported as “Colony Forming Units Per Gram (CFU/g).” Another process called quantitative polymerase chain reaction (qPCR) utilizes machinery that extracts DNA from the microbes, which is then genetically sequenced to identify the organism. States that mandate cannabis testing vary in permissible levels of microbial contaminants. For example, Colorado requires products to test negative (meaning no detection) for most molds and bacteria but Washington testing mandates that “Total Combined Yeast & Mold Count to be not more than 1,000 CFU/g.”
The cannabis plant is like any other plant, prone to disease and infestation by pests. Chemicals such as insecticides, herbicides, and fungicides are being used by many growers despite the fact that most patients do not want these chemicals in their medicine. There has been no research investigating the side effects from pesticides inhaled or ingested specifically related to cannabis use. However, studies clearly show that pesticides have been linked to cancer, skin irritation, endocrine dysfunction, neurologic disorders including Alzheimer’s disease and ADHD, reproductive problems and birth defects.
States where cannabis is legal for medical and/or recreational use have allowed for certain pesticides based on previous approval for use on food intended for human consumption. I strongly recommend that you avoid these chemicals in your food and in your cannabis!
Although cannabis analytic laboratories can test for many different types of pesticides, it is not mandated in most cannabis states. In a recent investigation, 26 cannabis samples were purchased from legal stores in the state of Washington. Pesticide analysis at a state certified legal licensed laboratory revealed that 22 tested positive for pesticides!
There is a burgeoning interest in organic cannabis farming. However, the USDA still does not recognize cannabis as a legal crop and organic certification agencies are prohibited from certifying cannabis from these growers. Until such certification exists and pesticide testing is mandated, patients should seek out and only obtain cannabis that has been tested for pesticides by a responsible supplier or collective.
Many potential cannabis patients are turned off by the idea of smoking. You do not have to smoke cannabis to get the benefits! There are many different ways to use cannabis as a medicine, but it is important to understand how the different delivery methods may change the effects.
With inhalation, the maximum blood concentration of THC occurs within minutes. The psychoactive effects start within seconds to a few minutes, reach a peak effect in 30 minutes and taper off within 1-4 hours, depending on the dose.
The advantages of inhalation include rapid onset of effects and easier dosing. Since effects are felt fairly quickly, most patients are able to adjust their dose to the desired effect and therefore unwanted side effects are minimized.
Vaporization is much preferred over smoking as it eliminates the toxins from the burning plant matter and reduces the resultant irritation to the lungs. Despite the belief that bongs or water pipes act as a “filter,” they actually do not decrease the amount of tar or other particles in the smoke. In fact, water pipe or bong smokers actually inhale 30% more smoke to get the same effect as a pipe or joint. Although THC is not water soluble, the water traps THC without trapping very much tar, so the “hit” that is inhaled has less medicinal compounds and more toxins. I do not encourage my patients to use bongs or water pipes.
Vaporizers are devices that heat up cannabis and emit a vapor that contains the medicinal compounds without the products of combustion like tar, carbon monoxide and particulate matter. Widely considered to be a “cleaner” way to inhale cannabis medicine, vaporizing produces no smoke and virtually no toxins.
Advantages of vaporization of cannabis flower are:
Vaporizers work by heating the cannabis flower without burning it. THC, CBD and other cannabinoids and terpenoids will boil off and become a vapor between 315-360° F. This vapor is then inhaled without the contaminants contained in combustion. Vaporizers can create vapor by two different methods. With conduction, one places the cannabis flower on a surface that heats up like a hot plate, and the molecules of medicine in the flower that touch the hot surface will vaporize. With convection, air is heated up and then passed through the plant material, vaporizing the medicine. The cannabis flower should be ground up in both methods to improve the extraction of the medicine.
Some vaporizers heat ground-up cannabis flower, and some heat processed cannabis oil. Over the past few years, some patients and recreational users have started to use “e-cigarette” type vaporizers, also known as pen vaporizers. In order to use these devices, the cannabis flower must be processed into a liquid form, usually an oil, that is then placed into a cartridge or chamber and inserted into the e-cigarette device.
Residual solvents may be left in the final product during the manufacturing of oils for use in these vaporizers. Other additives such as propylene glycol and glycerine may be present and with heat, will change to formaldehyde. As mentioned earlier, I recommend that you avoid products that may contain residual solvents or these additives. Oils that are processed using the supercritical CO2 method are generally considered to be safe. If there is any doubt about a product that you want to use, inquire about testing results or have a sample tested by a laboratory to ensure that it is clean and safe.
In terms of dosing, it is difficult to know the exact milligram dose when inhaling cannabis by smoking or vaporizing. However, with practice, most patients that inhale find they can easily medicate without fear of overdosing. One should and must use caution if the product is considered a concentrate as the potency can be quite high, causing an overdose for an inexperienced patient.
When cannabis is ingested through drinks or edibles, the onset of effects begin after 30-90 minutes, but they can vary widely person to person. The effects reach their peak in 2-3 hours and last for approximately 6-8 hours, depending on dose.
THC absorbed through the intestinal tract will pass through the liver. This is called the “first pass effect.” Much of the THC will be broken down to a cousin compound of THC, called 11-hydroxy-THC, which is psychoactive on its own and, when combined with THC, increases the potency of the psychoactive effects. Ingestion produces a different effect than inhalation for most cannabis users, with the effects described as “more relaxing” or as a “body high.” Some patients prefer this effect and others do not.
The advantages of ingestion are that smoke is avoided, there is no need for equipment such as a vaporizer, the duration of effect is longer and there is no odor. Edible forms of cannabis can be taken discreetly. Due to the variation in bioavailability (how much you absorb) and in the products themselves, dosing of edibles is more difficult.
Medical cannabis patients are advised to start with very small amounts (especially for THC-rich edibles), wait for at least 90 minutes and repeat the dose if no effect is felt. Since ingested THC is metabolized to the more potent 11-hydroxy-THC in the liver, new or inexperienced users can easily overdo it. The effect from edibles can be quite potent, even with small amounts. In fact, the most common reason for cannabis overdose symptoms (increased heart rate, anxiety, excessive sleepiness, hallucinations or paranoia) is the ingestion of too much of an edible THC-rich cannabis product. That being said, many patients do very well with edibles when they have been educated on the proper way to dose them.
In most states where medical cannabis is legally available, edible products are tested and labeled with potency of THC, CBD, CBN, THCA, CBDA and occasionally with the terpenoid profile. Always check the wrapper for the potency information, as it can be quite helpful in figuring out the dose. I recommend using ONLY cannabis products that are properly tested and labeled.
Cannabis Tincture, 1928
Cannabis tinctures or extracts have been made for hundreds of years. Pharmaceutical bottles of cannabis tincture that were made in the 1920s report on the label that cannabis is an “analgesic” and a “powerful sedative.”
By definition, tinctures are alcohol-based liquid concentrates, and extracts are oil-based liquid concentrates. In the cannabis industry, however, the terms tincture and oil are often used interchangeably. Most patients use these products sublingually (under the tongue) where they are quickly absorbed through the mucus membrane in the mouth. The medication goes directly to the bloodstream, bypassing the liver and avoiding the first pass effect described above. Effects are usually felt within 15-60 minutes and can be similar to those from inhaled THC. The liquid can be dispensed with an eyedropper, a needle-less syringe, or a sprayer. Most patients start with a small number of drops or sprays and increase the dose until the desired effects are achieved.
Another sublingual form of cannabis is the dissolvable strip, similar to breath strips. Patients often start with a small piece of the strip, which is then placed under the tongue. The dose may be repeated, with a wait time of at least 60 minutes before taking more if no effect is felt. The effects can be similar to inhaled cannabis.
Advantages of sublingual forms of cannabis are the avoidance of smoke, faster absorption than orally ingested forms, a minimal first pass effect in the liver, no odor and discreet use. In addition, patients can make their own tinctures and extracts out of their preferred chemovars if they choose to do so. Another very important advantage is that patients who require higher doses of THC or CBD can use concentrated cannabis oils to deliver larger doses in small volumes.
I recommend only using tinctures that are tested and properly labeled. Reading the label will tell you how many milligrams of THC and CBD are in one spray or one milliliter (ml).
Pediatric patients and patients with disabilities may not be able to cooperate with certain delivery methods. I have found that tinctures work well for these patients as they can be taken by mouth, hidden in food, or even given through a gastrostomy tube. Concentrated tinctures are also advised as a larger milligram dose in a smaller volume is easier for patient compliance.
Cannabis can be made into ointments, salves, lotions and alcohol preparations and applied to the skin to treat local pain (such as in arthritis) or rashes (such as psoriasis or eczema). These preparations have been used in India and Latin America for hundreds of years with reports of significant pain relief, especially for joint pain and for relief of certain skin rashes. There is evidence that topical cannabis is effective treatment for skin infections such as MRSA, a resistant type of bacterial skin infection.
Psychoactivity with topical cannabis use is rare. Preparations are currently available that are THC-rich, CBD-rich or a combination of both cannabinoids.
A number of scientific studies researching the effects of topical preparations of cannabis demonstrated the following:
Many of my patients use topical preparations successfully for arthritis, especially on the smaller joints, such as hands, feet, elbows, and knees. Some patients report relief of bursitis pain, plantar fasciitis pain and scar tissue pain. A few patients even find relief of neck and low back pain and a few report that nerve pain responds as well. Contact dermatitis, psoriasis and eczema have all been successfully treated with topical cannabis (alcohol based products should be avoided in these cases). There are anecdotal cases of patients applying cannabis to precancerous or small cancerous lesions with resolution of the lesions.
Topical preparations are not standardized and vary widely in ingredients, chemovars used, and potency. Sometimes patients have to experiment with a few different preparations to find the one that works best for their condition.
Since there have been a few cases of allergic reactions to topical cannabis products, I recommend applying a small amount as a test before applying to a larger area of skin.
Although there are many people that report good results using cannabis suppositories, there is no scientific evidence that absorption of THC occurs through rectal delivery. A study of rectal cannabis suppositories used in monkeys reports that THC is not absorbed rectally. However, when a chemical compound called hemi-succinate is combined with THC, absorption is double that of oral ingestion of THC. These types of suppositories were used in the lab only and are not available to patients yet. I rarely recommend THC-rich cannabis through the rectal route because we are still uncertain of the amount of medicine that gets into the system. Very little research about CBD via the rectal route exists, but one study found that rectal CBD reduced colitis (inflammation of the colon) in mice.
Transdermal patches of cannabis are of great interest to patients as this method of delivery has many benefits, especially when compared to oral delivery of cannabinoids. Compliance is easier for most patients and first pass effect through the liver can be avoided. One problematic issue with patches is that cannabinoids are fat-based compounds that do not mix with water and the aqueous layer of the skin may interfere with absorption into the bloodstream. If permeation enhancers, which are compounds that promote the flow of the drug through the skin, bioavailability is improved. A few studies have looked at the use of permeation enhancers with cannabinoids and I expect that in the near future, a number of cannabinoid patches with different cannabinoid profiles will be available for use.
Figuring out which cannabis preparation to take can be confusing. When searching for cannabis medicine, two terms – ratio and concentration – are important to understand.
Ratio tells how much CBD is in relation to THC in a particular cannabis plant or preparation.
If a cannabis plant or product lists a ratio or the word “CBD” on its label, it contains some amount of CBD. If there is no ratio or the word “CBD” is not listed on the label, it is very likely a product high in THC and has negligible amounts of CBD.
If a cannabis product is labeled 5:1 CBD:THC, it contains 5 parts CBD to 1 part THC. Said another way, it has 5 times more CBD than THC. If the product is labeled 20:1, it contains 20 parts CBD to 1 part THC and has 20 times more CBD than THC.
Knowing the ratio allows patients to determine whether the product will cause psychoactivity and what the effects are likely to be. In general, for inexperienced users, ratios over 10:1 CBD:THC (for example, 10:1, 15:1, 20:1, etc.) will not cause psychoactivity. Ratios under 10:1 can cause psychoactivity for some patients.
The ratio of CBD to THC is most important for those patients who do not want to experience psychoactivity, or for those who want the benefits of both of these amazing compounds.
Concentration tells how much CBD and THC in milligrams (sometimes expressed as percent) are in the plant or preparation. Knowing the milligrams of CBD and THC leads to calculating the ratio.
For example, if you have a bottle of cannabis oil that has 20mg of CBD per 1 milliliter (mL) of oil and it also has 10mg of THC per 1mL of oil, the ratio can be calculated by dividing 20mg of CBD by 10mg of THC, which equals 2:1. This oil has 2 times more CBD than THC.
Knowing the concentration not only helps the patient figure out the ratio, but also helps with proper dosing. In the example above, the oil has 20mg of CBD per 1mL. If your healthcare professional recommended that you take 10mg of CBD, you would take 0.5mL of the oil to get this dose.
Be aware that just knowing the ratio does not tell you the milligrams in the product. A 2:1 CBD:THC product may have 20mg of CBD and 10mg of THC, but it could also have any amount of CBD that is two times more than THC ( for example 100mg CBD and 50mg THC will also have the same 2:1 ratio). However, if you know the milligram concentration of both CBD and THC, you can always determine the ratio by simple division.
In sum, knowing the ratio allows you to know the likely effects of the product and knowing the concentration allows you to correctly dose in milligrams.