Understanding Medical Cannabis (Marijuana)

What is marijuana?

Marijuana is made up of the dried leaves and flowers of a plant called Cannabis. In the United States, federal law does not allow the use of cannabis, but many individual states have made cannabis use legal.

Many people think of marijuana or cannabis as a plant used to get “high,” but the Cannabis plant can be used in a few different ways. Certain compounds (parts) of the plant can be changed or taken out to remove the “high” feeling. We will point out the compounds found in cannabis and how they can be used to help with many cancer symptoms and side effects.

Cannabis Plant Species

There are two main types (species) of plants used as medical marijuana: Sativa and Indica. Most cannabis is a hybrid (mix) of both Sativa and Indica. Each kind can affect people differently depending on how their bodies handle it, as well as the terpenes that are made by certain strains (discussed below).

• Sativa plants grow in moist areas and are tall and skinny with long, thin leaves. Sativa species were thought to be more uplifting and energizing.
• Indica plants grow in arid (dry) areas and are a shorter, stubbier plant with wide leaves to take in moisture. Indica species were thought to be more calming, some even sedating which means they cause sleepiness.

What are cannabinoids?

The cannabis plant has more than 130 chemical compounds called cannabinoids, with even more that we don’t know about yet. Out of the 130, 2 have been looked at for medical use: THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol). These chemicals have effects on your body like medicines do. They can affect your central nervous system (CNS) and immune system in a few ways:

• THC is the part of cannabis that can cause a “high” feeling. It has been found to help with pain, nausea, and insomnia.
• CBD is the part of cannabis that can help with anxiety, inflammation, and pain. It has no psychoactive (affecting the mind) effects.

The Balance of THC and CBD

Cannabis strains are grown to have different amounts of THC and CBD to meet the needs a person may have. This is called the THC:CBD ratio. THC and CBD work better together than either does alone. These products fit into 3 groups:

• THC dominant: These strains have more THC than CBD and can cause a strong “high,” sleepiness, and anxiety. How high you feel can vary based on your tolerance. For this reason, you are often told to start with a low dose and work your way up.
• CBD dominant: These strains have less THC than CBD, letting you have a clear head and keep your normal roles & responsibilities. When there is more CBD than THC, you will likely not have any psychoactive change.
• Balanced CBD and THC: These can have a slightly higher amount of either part but are more balanced than the strains listed above. When there is a similar amount of CBD and THC, the CBD will cancel much of the psychoactive effects of the THC compound.

How do cannabinoids work?

There are receptors in our body that make up the endocannabinoid system (ECS). This is one of the most widely spread receptor systems throughout our bodies. Everyone’s ECS is different. Our bodies naturally make “endocannabinoids” that work with the ECS receptors. The ECS system helps our body keep balance (called homeostasis). Cannabinoids that come from plants (like cannabis plants) are also able to work with these receptors.

The two major ECS receptors are CB1 and CB2 receptors:

• CB1 receptors are mostly found in the nerve cells of your brain and spinal cord. These are the receptors that THC interacts with to cause psychoactive effects or the “high.”
  • CB1 receptors can also be found in your spleen, GI tract, reproductive and urinary systems, endocrine system, and white blood cells. Because these receptors are found in so many parts of your body, cannabinoids can be used for many things.
• CB2 receptors are often found in your immune and hematopoietic (blood cell) systems. They are also found in your brain to a lesser degree than CB1 receptors.

What are terpenes?

Terpenes are compounds or essential oils found in many plants and some insects. They cause some of the taste and smell of the object. Terpenes bind to receptors like cannabinoids, causing certain results in your body, and can act on tissues and cells in your immune system. 

There are hundreds of terpenes, but there are only a handful of more common ones. Many labs that study cannabis have the terpene content on product labels, allowing you to choose a strain based on the terpenes it has. The more common cannabis terpenes are Myrcene, Terpinolene, Limonene, Humulene, Pinene, Linalool, and Caryophyllene.

Terpenes work together with cannabinoids. This is known as the “entourage effect.” Some studies have found that using one cannabinoid, without the entourage of compounds found in the cannabis strain it came from, has less benefits.

How is cannabis used in cancer care?

Cannabis products are most often used to help with the symptoms of cancer. It may be used to help with pain, nausea, anxiety, and insomnia, and it can increase your appetite when weight loss is a concern. Some compounds of cannabis are being studied to see if they can slow down or stop cancer cell growth. Research is needed to know how it might work, and which products and cancer types will have the best results.

How is cannabis taken?

Cannabis can be taken or used in its whole plant form (often the flowers or “buds” of the plant) or compounds taken from the plant (THC or CBD). It can be taken in 3 main ways:

• Inhalation (through smoke or vapor).
• Oral consumption (by mouth).
• Topically (through creams, lotions, ointments, etc).

Different states have made different methods or products legal, so you may not have these options depending on where you live.

Inhalation of Cannabis

Inhalation means breathing in. Cannabis can be smoked in a pipe, hookah, or rolled into a “joint” (rolled in cigarette paper) or “blunt” (rolled in tobacco paper). 

Cannabis can also be inhaled in vapor form, called "vaporized." This is done using a vaporizer (vape), which heats the product enough to release the cannabinoids but does not ignite or burn the product.

Many types of vaporizers can be used with cannabis. Some use the dried cannabis flower (bud), while others use cannabis oil or cannabis wax (also called shatter or resin). The cannabis may be added directly to the vaporizer or come in a prefilled cartridge that fits into the device.

Vaporization works quicker than oral consumption methods, often in as little as 1 to 15 minutes. It can last 1 to 3 hours, which is shorter than when taken by mouth. During vaporization, CBD and THC are inhaled into the lungs along with other compounds. This can be a concern, mostly for people with lung disease or cancers affecting the lungs.

Taking Cannabis by Mouth

There are a few ways to take cannabis by mouth, such as tinctures, capsules, oils, and edibles:

• Tinctures are liquids that are mainly used sublingually, meaning it is placed under the tongue to sit for about 30 seconds. This lets it be quickly absorbed and can start working in 15-30 minutes. Sublingual cannabis tends to last about 2-4 hours in the body. A tincture (liquid form) can also be swallowed directly or placed in a liquid beverage, though this takes longer to work (30-90 minutes).
• Oils can be used as a sublingual (under the tongue), can be swallowed, or taken in a capsule/softgel. CBD and THC oils often come in 3 types:
  • Full-spectrum– Has all the compounds found in the source product, such as THC, CBD, terpenes, and other cannabinoids.
  • Broad-spectrum– Has many of the compounds from the source plant, but THC is removed.
  • CBD isolate– Has only CBD with all other compounds removed.
• Edibles (or cannabis-infused foods) are food items or drinks infused with active cannabis compounds, like THC. They are made by heating raw cannabis to activate its ingredients, blending it into a fat source like butter or oil, and adding that mixture into foods like brownies or gummies. Because edibles must pass through your digestive system, they take 30 to 90 minutes to start working. The effects peak around 2 to 3 hours after you eat them. Once the high begins, the experience is usually much more intense than smoking and can last between 4 to 12 hours.

Using Topical Cannabis

Topical cannabis is made by heating the cannabis flower to activate the cannabinoids and making an extract from this. This can be made into a lotion, cream, or ointment. These can help with pain relief in the area they are used. The cannabinoids are not absorbed (taken in) by your bloodstream, so there is no risk of getting high. Topical cannabis works quickly, within 1 to 10 minutes and can last up to 5 hours.

Another “topical” method is transdermal, which means the cannabis is taken in by a patch that is placed on your skin. These compounds are absorbed into your bloodstream. THC is absorbed, so there is a risk of psychoactive effects. These are made as either THC alone or a balanced formula that has both THC and CBD.

How do I get access to cannabis?

Each state has its own laws and processes for getting access to medical cannabis. In a few states, cannabis is legal for all adults. In most states, you must have a health condition on that state’s list of conditions to get medical cannabis. If you have a medical condition that qualifies you, you will need to get a medical marijuana card to visit and buy at a dispensary (the place cannabis products are sold), as well as to carry these products. In some states, you are also able to grow small amounts of cannabis.

The first step is to visit a provider registered with your state who can suggest or certify you for medical cannabis use. In some states, this must be a doctor (MD or DO), while nurse practitioners (NPs) and physician’s assistants (PAs) can do so in other states. Since marijuana is federally illegal at this time, they cannot write a prescription for it as they do with other medications. Instead, the provider may recommend marijuana and can give you some guidance as to the type that might benefit you most. For instance, a person with breathing problems may be told not to use vaporized cannabis. You will then need to follow your state’s process for getting your medical card.

How does cannabis from a dispensary differ from recreational marijuana?

A dispensary has trained staff to help you choose products. They can help you choose the right product and ratio of THC:CBD for your needs. Marijuana from a dispensary is regulated and labeled with ingredients and amounts so you know and are comfortable with what you are using. Recreational marijuana is not regulated. You cannot be sure what you are getting, if there are contaminants, or if it is safe.

What about the CBD products I see in the mall/grocery store?

CBD products found in stores and online are made from the hemp plant, which has less than 0.3% THC and will not cause any “high” effect. The main difference between hemp and marijuana is that hemp makes much less THC and does not have many of the other helpful compounds found in cannabis. For this reason, CBD oil from hemp may not have the same effects as CBD from cannabis.

When buying CBD oil from a cannabis dispensary, you will need to look at the THC content. The staff in the shop can help you find how much THC is best for your needs. Every person’s body is different, and you may need to try a few products before you find the best one for your needs.

How can I learn more?

There are many resources for information about medical marijuana and CBD. Many states do not allow reciprocity, meaning you cannot use your card to buy medicinal cannabis outside of the state where you are registered. There may also be legal concerns with traveling across state lines with products.

If you are interested in learning more, the list below can help you get started in your research:

• Americans for Safe Access – Information about each state’s laws and rules and other resources. https://www.safeaccessnow.org/becoming_a_state_authorized_patient
• Cannabis and Cannabinoids from the National Cancer Institute. https://www.cancer.gov/about-cancer/treatment/cam/patient/cannabis-pdq
• Society of Cannabis Clinicians. https://www.cannabisclinicians.org/resources/patient-resources/
• Leafly – This website sells products, and while OncoLink does not endorse their products or product/dispensary recommendations, they have a wealth of educational information on their website. https://www.leafly.com/news/cannabis-101