What Are Cannabinoids?

Used for Pain, Cancer, and Autoimmune Diseases

Cannabinoids are chemicals found in the Cannabis plant, which is the source of hemp and marijuana. While scientists have identified at least 113 different chemicals in the plant, two have become popular for treating pain plus a wide variety of conditions and symptoms, including cancer, inflammation, and mental illnesses:

  • Tetrahydrocannabinol (THC), the psychoactive compound that causes the “high” of marijuana
  • Cannabidiol (CBD), which is often derived from hemp and doesn’t cause a high
Cannabinoids
seksan Mongkhonkhamsao / Moment / Getty Images

Can Cannabinoids Offer Any Benefits?

Research has suggested myriad positive effects of marijuana and different preparations of THC and/or CBD. They’re currently used for several purposes and more possible uses are on the horizon.

Current Uses

Some of the current uses of cannabinoids include:

These uses have different levels of backing with scientific evidence. So far, no uses of marijuana are approved by the U.S. Food and Drug Administration (FDA), but the FDA has approved some pharmaceutical products containing cannabinoid ingredients.

Possible Future Uses

Early studies suggest cannabinoids may be beneficial at fighting cancer by:

  • Helping kill some cancer cells
  • Reducing the size of some other cancers
  • Slowing the growth of cancer cells in one of the most serious types of brain tumor
  • Reducing nausea from chemotherapy
  • Increasing the effectiveness of radiation treatments

These substances are also under investigation as treatments of diseases of the immune system, including:

Autoimmune diseases (such as MS, lupus, Crohn’s disease, and rheumatoid arthritis) may benefit from multiple functions of cannabinoids because it alleviates pain and inflammation while also regulating the immune system.

How They Work: The Endocannabinoid System

Cannabinoids affect your body through the endocannabinoid system (ECS). That system is named for substances your body naturally produces—and depends on—that are very like plant-based cannabinoids. The ECS has far-reaching effects on your body, and that’s why cannabinoids are believed to have so many different medicinal uses.

A major job of the ECS is homeostasis, which regulates many of your body’s essential functions, including:

  • Hormone levels and fertility
  • Heart rate
  • Body temperature
  • Hunger and digestion
  • Immune function
  • Sleep
  • Mood
  • Memory and concentration
  • Pain
  • Motor control
  • Awareness of your senses

Your endocannabinoids communicate with your nervous system to keep all these things within acceptable parameters. When you consider that, it makes sense that cannabinoids can treat numerous medical problems.

An important difference between your endocannabinoids and cannabinoids from an outside source, however, is that yours work in precise coordination with only the system that needs correcting at that moment. When you inhale cannabinoids from, say, smoking marijuana, they flood through your whole body and make both desirable and undesirable changes at the same time.

Cannabinoids and the FDA

So far, the FDA has approved two medications made from lab-created THC: Marinol (dronabinol) and Cesamet (nabilone). It’s also approved Epidiolex, a purified formulation of CBD, for two forms of childhood epilepsy: Lennox-Gastaut syndrome and Dravet syndrome.

With growing bodies of evidence for multiple beneficial medical effects, you might wonder why medical marijuana and cannabinoids aren’t FDA-approved. The issue is that research is still in its early stages, and the FDA requires large studies, including hundreds of participants, that evaluate both the effectiveness and the safety of those drugs for the specific group of people it’ll be used for.

That’s a long, expensive, and arduous process. However, as time goes on and more research is conducted, more cannabinoid-based drugs may come on the market for a wider variety of illnesses.

Are They Legal?

Laws regarding hemp-based products, including CBD, have now changed at the federal level, making CBD products legal nationwide. Numerous states have made marijuana legal for medical or recreational use, as well, but it is still considered illegal at the federal level. Be sure you know the laws for your state.

Work Issues

Even if medical or recreational marijuana is legal where you live, certain jobs may not allow you to use these products. Be sure to check company policies before using cannabinoids.

CBD products can’t legally contain more than 0.3% THC, so these products shouldn’t cause you to fail a drug test (as long as the company selling it is preparing, testing, and labeling the product correctly).

Possible Side Effects

Cannabinoids are considered to have fewer and milder side effects than many pharmaceutical drugs they may be able to replace. Don’t make the mistake, though, of thinking that “natural” products are side-effect free—most natural products, including cannabinoids, can cause side effects and may interact negatively with other drugs. The specific effects that you may experience depend on what cannabinoids you’re taking.

Marijuana and THC

Most of the side effects of marijuana stem from its effect of overstimulating parts of the brain. Many of these side effects may be due to THC and include:

  • Altered senses (e.g., colors appearing brighter)
  • Altered sense of time
  • Mood changes
  • Impaired motor skills
  • Difficulty thinking
  • Impaired memory

When taken in high doses or with regular use of highly potent strains, marijuana may cause:

  • Hallucinations
  • Delusions
  • Psychosis

In teenagers, marijuana is shown to cause problems with brain development and can negatively impact thinking, learning, and memory. Researchers believe it may prevent the brain from building important connections between different areas. It’s not yet known how long these effects may last; some changes may be permanent.

Side effects specific to smoking marijuana include coughing, increased phlegm, and a higher risk of lung illness and infection. However, smoking marijuana doesn’t appear to increase the risk of lung cancer.

A real benefit of marijuana or THC is that they don’t cause overdose, which makes them especially attractive as an alternative to opioids for chronic pain.

CBD

Researchers still have a lot to learn about the potential side effects of CBD. Some that have been reported include:

  • Dry mouth
  • Low blood pressure
  • Lightheadedness
  • Tiredness
  • Altered drug-processing liver enzymes
  • At high doses, increased tremor in Parkinson’s disease

The World Health Organization reports that possible side effects may include:

  • Altered hormone levels
  • Stimulation of the immune system at low levels, but suppression of the immune system at higher levels

If research supports the hypothesis of immunosuppression at high doses, this “side effect” could be used as a primary effect for treating autoimmune diseases or conditions that feature an overactive immune system, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

CBD is not addictive and does not cause overdose. That, combined with the absence of a high that impairs cognition, makes this drug especially attractive to many people with chronic pain.

Drug Interactions

Information on potentially negative drug interactions involving cannabinoids is scarce. However, some early case reports suggest possible problems with:

Check with your healthcare provider before combining cannabinoids with other drugs that can have a sedative effect. Alcohol, even in small amounts, has been reported to increase blood levels of THC, thereby heightening its effect. Use caution when combining these drugs.

According to a study on mice, the drug Neurontin (gabapentin) may have a positive interaction with THC, making it more effective against a type of pain called allodynia and for a longer span of time.

A 2016 study involving complex drug regimens including opioids, tricyclic antidepressants, and others found no negative interactions with cannabinoids.

Possible At-Risk Groups

People with kidney or liver disease and elderly people should be closely monitored by a healthcare provider while taking cannabinoids.

THC and CBD should not be used during pregnancy or breastfeeding. The U.S. Surgeon General says marijuana use during pregnancy may affect the development of the baby's brain. It may also cause low birth weight and increase the risk of premature birth and, possibly, stillbirth.

Animal studies have shown that THC use during pregnancy or nursing can cause long-lasting problems in the child, including learning problems and abnormal patterns of social interaction. THC has been found to linger in breast milk for up to six days.

CBD, also in animal studies, has been found to damage the reproductive systems of male babies. It's believed to be transferred through breast milk, as well. Possible contaminants, including THC and pesticides, may also harm the baby.

Dosage and Preparation

Standard dosages have not been identified for cannabinoids. Be sure to talk to your healthcare provider about any cannabinoid-containing products you want to try to make sure you’re using it safely. Your practitioner may be able to offer guidance on dosage, as well.

Numerous forms and preparations of cannabinoids are available. You can choose between:

  • Smoking
  • Vaping
  • Edibles
  • Oils
  • Capsules
  • Isolates (purified crystalline form)
  • Topicals, such as creams and balms

Products other than CBD isolates may have the distinctive skunky smell and taste of marijuana. Oils and isolates may be added to food or beverages or taken sublingually (under the tongue) and then swallowed.

Some products may contain only one cannabinoid while others are “full spectrum,” which means they contain all the cannabinoids of the hemp plant, or “broad spectrum,” which means they contain most of the cannabinoids but, usually, not any THC. Full-spectrum and broad-spectrum products may offer more benefits than purely CBD products. (Even full-spectrum CBD must not contain more than 0.3% THC.)

What to Look For

When legally purchasing medical or recreational marijuana or THC products, look for a dispensary with knowledgeable employees who can help you find the right strain and formulation to fit your condition and preferences. If it’s important to you, ask about organic products and other cultivation methods.

Buying marijuana in states where it’s still outlawed is not only a legal risk, it could also pose a health risk as it could be contaminated or “laced” with other drugs.

When buying CBD, look for companies that have had their products tested at third-party laboratories and make the lab reports available to you. (You may need to ask.) They should also display a valid Certificate of Analysis on their website or in their store.

You can also check on the lab that did the testing to make sure they’re accredited by the International Organization for Standardization. A quality product should be free of contaminants and the levels of cannabinoids should closely match the product label (small variations are expected), and it should comply with the legal requirement of less than 0.3% THC.

Also, look at all the ingredients of the product to make sure you’re not allergic or sensitive to any of them, and that they’re all ingredients you’re comfortable with. Some CBD products may contain other medicinal products, and you want to make sure you’re getting the right mix of products for your condition(s). For example, if the product contains B12 to help with pain relief, you won’t want to take that for insomnia, as B12 may boost your energy.

When choosing topicals, make sure you're getting a product designed to treat pain and not one that's formulated for cosmetic uses, such as an eye cream.

For any cannabinoids, consider whether it’s important to you that they’re organic. It’s also a good idea to look for products made from hemp grown in the United States because of standards that have been put in place by the U.S. Department of Agriculture (USDA). Special programs in three states—Colorado, Kentucky, and North Carolina—also help guarantee the product was made with quality hemp.

Keep in mind that the claims made by non-pharmaceutical companies selling cannabinoid products have not been evaluated by the FDA and may not be backed by research.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health: National Institute on Drug Abuse. Marijuana as medicine.

  2. National Institutes of Health: National Institute on Drug Abuse. Marijuana.

  3. Iffland K, Grotenhermen F. An update on safety and side effects of cannabidiol: A review of clinical data and relevant animal studiesCannabis Cannabinoid Res. 2017;2(1):139–154. doi:10.1089/can.2016.0034

  4. World Health Organization: Expert Committee on Drug Dependence. Cannabidiol (CBD): Pre-review report. Thirty-ninth Meeting, Geneva.

  5. Alsherbiny MA, Li CG. Medicinal cannabis-potential drug interactionsMedicines (Basel). 2018;6(1):3. doi:10.3390/medicines6010003

  6. Russo EB. Current therapeutic cannabis controversies and clinical trial design issuesFront Pharmacol. 2016;7:309. doi:10.3389/fphar.2016.00309

  7. Hartman RL, Brown TL, Milavetz G, et al. Controlled cannabis vaporizer administration: Blood and plasma cannabinoids with and without alcoholClin Chem. 2015;61(6):850‐869. doi:10.1373/clinchem.2015.238287

  8. Atwal N, Casey SL, Mitchell VA, Vaughan CW. THC and gabapentin interactions in a mouse neuropathic pain modelNeuropharmacology. 2019;144:115‐121. doi:10.1016/j.neuropharm.2018.10.006

  9. U.S. Food and Drug Administration. What you should know about using cannabis, including CBD, when pregnant or breastfeeding.

By Adrienne Dellwo
Adrienne Dellwo is an experienced journalist who was diagnosed with fibromyalgia and has written extensively on the topic.