CBD vs. THC: Differences, Effects, and Legality

Learn everything you need to know the differences and similarities between CBD and THC, the two primary compounds found in cannabis.
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Humans have cultivated cannabis for over 2,500 years; in the U.S., a majority of states have passed legislation providing for the medicinal use of cannabis, and a growing number are legalizing it for recreational use. Public and scientific interest in the plant and two of its primary compounds—cannabidiol (CBD) and tetrahydrocannabinol (THC)—has increased in recent years.

CBDTHC

Conditions Treated

Pain, cancer and chemotherapy side effects, acne, seizure disorders, neurological disorders, high blood pressure, diabetes, depression, anxiety, substance addiction 

Pain, cancer and chemotherapy side effects, appetite loss, glaucoma, nausea, muscle spasms, depression, anxiety

Potential for Addiction

Lower than THC because it doesn’t affect neurotransmitter receptors in the same way as CBD

Higher than CBD due to its psychoactive side effects

Legality

Hemp-derived CBD legal on a federal level; states’ laws on CBD derived from cannabis strains with greater than 0.3% THC vary

Regulated as a Schedule I substance by the federal government; states’ laws on medicinal and recreational use vary

What Is THC? What Is CBD?

THC is the chemical compound responsible for the psychoactive effects users experience after consuming cannabis. More than 100 cannabinoids have been identified by researchers studying cannabis, and they have discovered that THC’s chemical structure is similar to that of anandamide, a neurotransmitter sometimes referred to as the “bliss molecule.” THC’s ability to mimic this neurotransmitter enables the body to bind to cannabinoid receptors.

Anandamide does more than just fabricate bliss, however; scientific studies have also suggested it plays a role in reinforcing the pleasure of socialization and even in inhibiting human breast cancer cell proliferation.

CBD, in contrast, produces a feeling of relaxation but without any of the psychoactive effects of THC. It should be noted that up to 5% of CBD users do, in fact, feel some psychoactive effect from the cannabinoid; however, this is a rare occurrence. It generally doesn’t provide sedating or euphoric effects, but it does have a slew of positive effects that have been increasingly explored for their health and medical benefits. CBD is primarily extracted from the hemp plant (low-THC cannabis), although it is also found and cultivated in cannabis plants with higher levels of THC.

How Are the Effects of THC and CBD Different?

Cannabis strains are bred for specific purposes, e.g., high THC and low CBD or vice versa. High-CBD strains tend to have fewer psychoactive effects without the euphoric effects provided by strains with higher THC levels.

In recent years, the number of methods for THC and CBD consumption has exploded. Wax, oil, hash, concentrates, edibles, tinctures, lotions, creams, skin patches, and, of course, smoking, have all become common methods of consumption for users to experience and reap the benefits of the positive effects of THC and CBD. One company has even introduced CBD-infused pillowcases. These compounds are not without negative effects for some users, although many of these are notably less severe than the potentially detrimental side effects of other, more traditional treatment options.

Possible Negative Effects of THCPossible Negative Effects of CBD

Trouble concentrating

Dizziness

Lethargy

Nausea

Dry mouth

Dry mouth

Anxiety 

Anxiety

Paranoia

Diarrhea

Fatigue

Fatigue

Hunger

Dry/red eyes

Are CBD and THC Addictive?

Experts argue that CBD is not addictive due to its inability to affect the body’s CB1 (brain) and CB2 (immune system) receptors in the same manner as some of the other compounds found in cannabis. Some studies have even suggested that CBD can help its users to wean off of addictive substances like alcohol and heroin.

Cannabis use disorder is identified as a diagnosable condition by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). The DSM-5 defines addiction to cannabis, as well as alcohol, caffeine, and other drugs, as fulfilling two or more of their 11 criteria for substance abuse. The number of criteria indicated determines the level of severity of addiction.

The risk for cannabis addiction and detrimental effects of cannabis abuse appears to be higher in those who use heavily during their teenage years. The strength of cannabis strains (measured by percentage of THC) has gone up as much as 300% in the last few decades, and despite THC’s reported medicinal qualities, the potential for addiction seems to increase in tandem with the increase in cannabis’ potency.

Aside from its touted health benefits, THC is also known to produce euphoria and relaxation, create hallucinogenic effects, heighten senses, and make the passage of time seem slower. The consumption of CBD, by contrast, doesn’t produce any of these psychoactive effects; rather, it supposedly counteracts some of the negative effects of THC, including anxiety and paranoia, as well as boasting its own beneficial medicinal effects.

CBD has been used to reduce pain from conditions such as arthritis, multiple sclerosis, and muscle spasms. It is also used as an alternative treatment for depression and anxiety, as studies have pointed to CBD’s ability to act on receptors for serotonin, a neurotransmitter thought to contribute to feelings of well-being and happiness, in the brain.

Will CBD Show Up on a Drug Test?

CBD itself shouldn’t show up on a drug test, but many cannabis strains with high levels of CBD contain trace amounts of THC, which may make a drug test turn up positive. If enough THC is present, the test will be positive, but it all depends on the quality and composition of the product. Read more about CBD and drug tests. 

How Do THC and CBD Work Together?

Some studies have suggested that CBD is actually more effective when combined with low amounts of THC. These studies suggest that, when combined, CBD and THC work to enhance each other’s effects. Scientists haven’t yet been able to determine how exactly this works; however, for example, one study found that combining CBD and THC had a stronger anti-tumor effect on high-grade gliomas (central nervous system tumors) than either compound on its own.

THC works as an agonist, meaning it’s a chemical that binds to a receptor to produce a biological action. THC is a partial agonist at certain neurotransmitter receptors, and studies have suggested it may be a full agonist at others. In contrast, CBD is an antagonist, which blocks these biological actions from occurring.

When the two compounds are consumed together, CBD’s antagonizing effect mitigates the agonizing effect of THC. The ratio of these two compounds will determine whether THC, as the agonist, is permitted to stimulate further biological actions. With multiple receptors present in the body, a higher ratio of CBD will prevent these biological actions from occurring as frequently as they would with a higher ratio of THC.

The need for a lower or higher concentration of THC in companionship with a CBD product depends on the type of pain or condition the CBD is being used to treat. Luckily, today’s medicinal and recreational cannabis markets provide for a wide array of CBD-to-THC ratios; at this point in time, due to a lack of regulation of the cannabis market, trial and error may be the best way to determine which ratio works best on an individual basis.

What’s the Difference Between THC and CBD?

The chemical makeup of THC and CBD are nearly identical⁠—21 carbon atoms, 30 hydrogen atoms, and 2 oxygen atoms. The atoms are arranged a bit differently in each compound, which helps to explain how each has different effects on humans.

CBD is used to relieve pain, heart problems, anxiety, depression, and even acne. In addition, it has been shown to have beneficial effects for those suffering from epilepsy, multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, and other neurological disorders. Research is also being conducted on CBD’s potential for diabetes prevention and substance abuse treatment.

CBD has also been shown to be beneficial for the treatment of cancer-related symptoms, as well as in treating some of the unpleasant side effects associated with cancer treatments. It has even been shown to prevent the spread of some forms of cancer and has exhibited antidepressant qualities in animals.

THC has been successfully used to treat pain, insomnia, anxiety, muscle spasms, and glaucoma, among other symptoms and conditions. While THC has long been thought of as merely the compound that gives users that “high” feeling, some studies have suggested that THC is, in fact, even more effective than its fellow compound of CBD in providing relief for negative symptoms caused by medical conditions. However, federal and state cannabis regulations have made research on THC-dominant strains more difficult to conduct than, for example, CBD extracted from hemp plants.

Cannabis Legality: How Are THC and CBD Regulated Differently on a State and Federal Level?

Both THC and CBD are illegal on a federal level, but some states have laws regulating their medicinal and/or recreational use. Dr. Sanjay Gupta’s 2014 documentary, Weed 2: Cannabis Madness, helped to readjust the public discussion surrounding CBD, focusing on its miraculous ability to prevent epileptic children from having seizures.

Epidiolex is the first FDA-approved anti-seizure medication made with CBD intended for treatment of severe seizures associated with Lennox-Gastaut Syndrome and Dravet Syndrome. The medication was approved to treat these rare seizure disorders in patients two years of age and older. This marks a significant step toward acceptance of CBD in the scientific and medical communities as an alternative to traditionally accepted forms of treatment.

However, the results of a 2019 study cast doubt on the safety of using CBD as a medical treatment. The study found that mice that were given high doses of CBD showed signs of liver damage within 24 hours⁠—many of them died or came close to dying within several days. This study brings light to the fact that there is still a lot scientists don’t know about the compound and, although many claims have been made about its positive effects, this study showcases a lack of conclusive data to support the claims made about CBD. More studies are needed to find conclusive data about the negative health effects of CBD, but this study in particular certainly made waves in the pro-cannabis community.

So, What About Hemp?

Evidence of hemp cultivation goes back over 10,000 years, making it one of the oldest known crops cultivated by humans. In the U.S., hemp is defined as a strain of cannabis plant containing less than 0.3% THC, and was bumped from its Schedule I status (reserved for substances with a high potential for abuse and addiction) by the Farm Bill in 2018.

Hemp is used to make paper, soap, carpeting, handbags, balms, shoes, and even fuel. Both hemp and cannabis plants are capable of producing high levels of CBD, but they are cultivated differently based on their different uses. Cannabis is optimized for its THC content and the size of its flowers, typically for consumption, while hemp is often cultivated to maximize its yield due to its multitude of uses in food and industrial products, as well as its ability to yield high levels of CBD.

The Farm Bill’s provisions essentially gave hemp-derived CBD the legal green light, while non-hemp-derived CBD is still considered illegal on a federal level, regardless of how low its THC level is.

The Future of CBD in America

It’s challenging to determine the full potential of CBD and other cannabinoids when federal restrictions are still in place on the research and cultivation of the compound. Much research still needs to be conducted in order to determine the benefits and detriments of THC, CBD, and other compounds found in cannabis.

Recent studies have indicated that a majority of Americans are in favor of legalizing cannabis, and the younger the demographic, the more likely they are to support legalization. Support for legalization has been steadily increasing over the last decade, despite nearly half of Americans reporting never having used cannabis in a 2017 national survey.

A lack of federal regulation results in a lack of quality control that’s important for the scientific validity of CBD and of cannabis in general as an alternative to traditional Western medicine. A lack of regulation in the testing of products, failure to achieve standardization and uniform dosage recommendations are hurdles the cannabis industry must overcome in order to bolster consumer trust in the cannabis and CBD industries.

CBD is in a “wild west” phase of its existence and regulation (or lack thereof). Companies are allowed to make claims about its medicinal and healing qualities that are unfounded and unproven by scientific evidence in order to sell their product. This has resulted in a booming industry that has flown just under the federal government’s radar. But the Farm Bill’s provisions regarding CBD have allowed for further research and exploration of CBD’s potential⁠—but is it enough? It could be several years before the FDA legalizes CBD fully to be used in dietary supplements and food products.

Due to the lack of FDA regulation of state-level medicinal and recreational cannabis products, it’s difficult to truly assess the quality of these products. As of now, companies that produce cannabis-derived products make all sorts of outlandish claims about their products, including that these products can “cure” certain ailments. Less strict federal laws on research and cultivation of cannabis compounds would allow for safer products, and it would enable scientists to more accurately measure the pros and cons of THC and CBD use.

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