If the extent of your knowledge CBD vs THC is that one gets you high and the other doesn’t, you might not be aware of how important it is for these chemicals to work together. The cannabis plant houses about one hundred molecules called cannabinoids. CBD (cannabidiol) and THC (tetrahydrocannabinol) are the two most abundant of these molecules. CBD and THC work best when consumed together, but the two cannabinoids have some important differences. We’ll explain what those are so you can make informed choices about cannabis.

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Molecular Structure

CBD and THC have very similar structures. They are both made of 21 carbon, 30 hydrogen, and two oxygen atoms. However, these atoms are arranged differently in each compound. Why should you care about the differences in chemical structure between CBD and THC? Because those differences help to explain the way that CBD vs THC affects us. We all have an endocannabinoid system (ECS). This system facilitates the way neurotransmitters send messages throughout our bodies. Those messages help to regulate pain, digestion, sleep, mood, immunity, and other biological processes. The ECS is made up of endocannabinoids, cannabinoid receptors, and enzymes. THC reminds our bodies of two endocannabinoids: AEA and 2-AG. Because THC is similar in molecular structure to AEA and 2-AG, it can bind to cannabinoid receptors 1 and 2 (CB1 and CB2). THC has a special affinity for CB-1 receptors which are densely located throughout the central nervous system. This is why THC produces psychoactive effects. Unlike THC, CBD does not bind much with CB1 and CB2 receptors. CBD produces its effects through many molecular pathways including serotonin receptors, vanilloid receptors, GPR55 receptors, and nuclear receptors. It can also affect the way that certain receptors send signals. The key takeaway is that CBD and THC affect neurotransmitter signaling through different channels.


The most notable difference between THC and CBD has to do with psychoactivity. THC will get you high, but CBD won’t. In fact, cannabis products with higher CBD content can make the effects of THC milder. Most people think of THC as recreational and CBD as medicinal. But the euphoric high produced by THC is thought to be extremely therapeutic. The medicinal/recreational effects of THC can include:

  • An altered state of consciousness
  • Euphoria
  • Relaxation
  • Increased sensation
  • Appreciate of the arts
  • Increased appetite

THC’s side effects can include:

  • Paranoia
  • Anxiety
  • Dry mouth
  • Red eyes
  • Impaired memory
  • Impaired perception
  • Impaired motor skills
  • Delusions
  • Difficulty concentrating
  • Hallucinations
  • Increased heart rate

CBD’s side effects are mild. They include nausea, irritability, and fatigue. It’s important to note that research suggests a synergistic relationship between CBD and THC (specifically with whole-plant, full-spectrum). It's thought that THC could provide immediate relief because of its impact on the central nervous system. CBD can reduce adverse psychological responses to THC. While the jury is still on how the efficacy of using to treat THC and CBD for ailments, some medical marijuana patients have expressed that they've found relief by using the substances to treat their symptoms. Note: This section contains information from one of our doctor reviewed our articles.


Federal law dislikes cannabis, but it really dislikes THC. Federal law classifies any cannabinoid coming from a cannabis plant containing more than 0.3 percent THC as illegal. This includes CBD. But what about the 2018 Farm Bill? Didn’t that legalize CBD? Yes. But only if the CBD is extracted from hemp—cannabis containing less than 0.3 percent THC. Also, the hemp must be cultivated in compliance with federal and state laws. So if you got your hands on CBD extracted from a cannabis plant containing 20 percent THC, that CBD would be considered federally illegal. Even if that CBD had been totally purified of all traces of THC. State laws vary. Most states have legalized some form of cannabis. It is more likely that CBD is legal in your state than THC.

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Drug Testing 

CBD does not show up on drug tests. Drug tests are designed to identify THC metabolites, not CBD. If you are consuming CBD products derived from cannabis containing less than .3 percent THC, it’s very unlikely that you will screen positive for cannabis. However, don’t confuse zero THC for low THC. Cannabis products that have THC listed on their labels, even in relatively low doses, may have enough THC to show up on a drug test. Make sure you trust the brand you’re getting your CBD from. If it’s a hemp-only brand, there shouldn’t be any THC in the product. While whole plant, full-spectrum cannabis products are ideal for medicinal benefits, they are also more likely to contain THC. You may want to avoid full-spectrum CBD products if you know you have an upcoming drug test. CBD isolate is purified CBD. These products contain nothing but CBD. Broad-spectrum products contain more than CBD (like terpenes), but no THC.  If you have a drug test in your future, these two CBD product types are your safest options.