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What are the Differences Between CBD and THC?

CBD and THC are the two most abundant of the many cannabinoids found in cannabis. They both interact with the endocannabinoid system but elicit different natural effects.

Cannabidiol (CBD) and tetrahydrocannabinol (THC) are the two most prominent cannabinoids found in Cannabis, the plant genus that includes both hemp and marijuana. While there are over 100 different cannabinoids so far identified in cannabis by scientists, CBD and THC are by far the most extensively studied and best understood.

CBD and THC both interact with the body through the endocannabinoid system, a vital signaling system responsible for regulating a wide array of functions, some of which include:

  • Pain
  • Appetite
  • Mood
  • Memory
  • Immune response
  • Sleep
  • Cycles of cellular life and death

Their chemical makeups are similar to the body’s own endocannabinoids, which allows them to interact with the endocannabinoid system’s cannabinoid receptors to alter the release of neurotransmitters in the brain.

Despite their similarities, CBD and THC have distinct differences that influence how they interact with the endocannabinoid system and subsequently the natural effects they elicit.

Here we compare the two cannabinoids – THC Vs. CBD.

Psychoactive Vs. Non-Psychoactive

One of the key differences between CBD and THC is whether the cannabinoid will cause a euphoric effect, or “high,” when consumed.

THC is the cannabinoid people think of when they think of marijuana. It is a direct agonist of the endocannabinoid system’s cannabinoid 1 receptors (CB1), found primarily in the brain and the central nervous system. The psychoactive effect that most associate with recreational or medical marijuana use is exclusively brought about by activating CB1 receptors.

CBD doesn’t bind with CB1 receptors and is actually is considered an antagonist of CB1 agonists. This not only means that CBD can never cause a high, no matter how much is consumed, but that it also acts to suppress the CB1-activating qualities of compounds like THC.

THC Dominates Marijuana, CBD Dominates Hemp

CBD and THC are both found throughout the seeds, stalks, and flowers of both hemp and marijuana. The two exist in cannabis plants in a wide range of proportions. However, while THC is most plentiful in marijuana, CBD is present in higher quantities in hemp.

In marijuana, THC dominates the plant’s chemical makeup. Marijuana is generally cultivated specifically to maximize its THC content. Over many decades, marijuana has been manipulated and cloned with particular emphasis on increasing its THC concentration and producing more powerful intoxicating effects. While THC content can be as low as 3 percent in marijuana, on average, marijuana strains today contain approximately 12 percent THC.

Hemp’s chemical makeup, on the other hand, is dominated by CBD. By definition, hemp’s THC content is no more than 0.3 percent, nearly 10 times less than the least potent strain of marijuana. Instead, hemp naturally has more CBD vs. THC, making it an ideal source of CBD from cannabis.

Different Atomic Arrangement

CBD and THC are considered structural isomers, which means they share the same chemical composition but their atomic arrangements differ. The two compounds share a molecular formula of C21H30O2 and molecular weights of 314.4 g/mol.

The atomic arrangements of the two cannabinoids differ slightly. Both CBD and THC are considered cyclic compounds, which means one or more series of atoms in the compounds are connected to form a ring. CBD comes with an open ring with a hydroxyl and alkene group, while THC supports a closed ring with an ester group.

CBD (with an open ring) v THC (closed ring)

It’s these slight differences in how their atoms are arranged that have the dramatic effect on how the two cannabinoids interact with the endocannabinoid system’s receptors.

Interaction with Cannabinoid Receptors

CBD and THC both interact with the body’s endocannabinoid system and its specialized cannabinoid receptors, CB1 and CB2. It is through these interactions that these two cannabinoids augment the endocannabinoid system and encourage balance. However, the ways in which the two cannabinoids interact with these cannabinoid receptors vary.  

THC directly binds with both CB1 and CB2 receptors, while having a higher affinity for CB1 receptors.

CBD has little affinity for the two cannabinoid receptors. Instead, it acts as an indirect antagonist of cannabinoid agonists. This means that CBD acts to suppress the CB1 and CB2 activating qualities of a cannabinoid like THC. CBD has also been found to interact with other non-cannabinoid receptors, including 5-HT1A receptors and the vanilloid receptor TRPV-1.

We’ve previously detailed the research findings on the effects of these cannabinoids interacting with the endocannabinoid system. You can learn more about the findings about CBD or THC.

Legal Status: THC vs. CBD

The legality of cannabinoid products in the United States is dependent on their concentration and source.

Marijuana and THC are both specifically listed in the U.S. Controlled Substances Act and therefore prohibited under federal law. Twenty-nine U.S. states and Washington D.C. have passed their own cannabis policies permitting the use of medical marijuana with high levels of THC, provided it’s recommended by a licensed physician. Eight of those states and Washington D.C. have gone a step further and legalized the recreational use of marijuana and THC.

CBD is legally available in the United States, but it must be derived from imported high-CBD, low-THC hemp. CBD itself it not listed under the Controlled Substances Act, so it’s legal in all 50 states provided it’s not extracted from marijuana.

If derived from marijuana, CBD is illegal unless obtained through a state-regulated medical marijuana program or in a state that permits recreational marijuana use. CBD products derived from hemp are considered dietary supplements in the U.S. and legal to buy and sell.

Side Effects and Safety: CBD Vs. THC

The psychoactive properties of THC can cause temporary side effects:

  • Memory impairments
  • Lowered reaction time
  • Increased heart rate
  • Coordination problems
  • Dry mouth
  • Red eyes

While there is a risk of some negative side effects from THC, according to the National Cancer Institute it is not possible to have a fatal overdose. Some studies have found evidence that cannabis strains high in THC can cause long-term negative psychiatric effects when consumed by adolescents, including increasing the risk of psychiatric disorders like schizophrenia.

Research indicates even large doses of CBD are well tolerated and safe. There have been some reports of dry mouth, light-headedness, and drowsiness. A recent research review examining the safety and side effects of CBD concluded that CBD appeared to be safe in humans and animals. Even chronic use of CBD by humans showed to cause no adverse neurological, psychiatric, or clinical effects.

Learn More about THC vs. CBD

You can learn more about CBD and THC, including what studies have so far discovered about their effects, by visiting our research and education page.

Post by Eve Ripley

Eve is a writer specializing in cannabis education and editorials related to cannabis industry news.

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