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Predicting Cannabis Strain Effects From THC and CBD Levels

March 23, 2017

Predicting Cannabis Strain Effects From THC and CBD Levels

Whether you’re an adult-use consumer looking for a specific kind of high or a medical patient seeking symptom relief, the THC:CBD ratio will strongly affect your experience. As Leafly has explored previously, CBD is able to diminish some of THC’s effects because it interacts with receptors in the brain very differently than THC does.

The psychoactive effects of cannabis depend on THC’s ability to activate the CB1 receptor. The presence of CBD changes THC’s ability to activate CB1 receptors and laboratory studies in both animals and humans, which tells us that CBD can diminish some of THC’s effects (Figure 1). This is a big reason why a balanced strain like Harlequin or Cannatonic will hit you very differently from THC-dominant strains like Blue Dream, Sour Diesel, or Northern Lights.

THC vs. CBD at the CB1 receptor

Figure 1: The psychoactive effects of cannabis depend largely on THC’s ability to activate CB1 receptors in the brain. Left: Activation of CB1 receptors by THC in the brain triggers many of the classical effects of cannabis. This includes pleasant effects like euphoria and relaxation and side effects like short-term memory impairment and anxiety, especially at higher doses. Right: CBD does not activate the CB1 receptor. Instead, CBD interferes with THC’s ability to activate the CB1 receptor, which can decrease some of THC’s side-effects. (Amy Phung/Leafly)


THC and CBD aren’t the only things that matter. Strain effects will also depend on the presence of other compounds, like terpenes. Nonetheless, the THC:CBD ratio is a huge factor in how a strain will affect you. Can we anticipate any general effects from the THC:CBD ratio alone?

Predicting Likely Strain Effects

It is well established that CBD does not have the psychoactive effects that THC does. When people take pure CBD, even at very high doses, it is well tolerated and produces no obvious intoxicating effects. We also know that when in the presence of CBD, some of THC’s effects are reduced. CBD won’t erase THC’s psychoactive effects, but the effects will be different.

Cannabis connoisseurs will be well aware of the general differences between the effects of THC-dominant vs. balanced strains, and will want to dig deeper into strain information (e.g. terpene levels). Novice cannabis consumers, by contrast, should start by understanding the basic differences between balanced vs. THC-dominant strains before worrying about further subtleties or experimenting with the more potent cannabis products.

Figure 2: Cannabis strains can be grouped into three broad categories based on their THC:CBD ratio. THC-dominant strains have significant THC levels but negligible CBD. Balanced strains contain significant levels of both THC and CBD, but generally less THC than THC-dominant strains. CBD-dominant strains (hemp) contain significant CBD levels and negligible THC. See this article for more information. (Amy Phung/Leafly)


Balanced strains like Harlequin or Cannatonic will still get you high, but your experience will be noticeably different compared to THC-dominant strains. Based on what we know from scientific studies, the effects of balanced strains may differ from THC-dominant strains in the ways listed below.

Important caveat: The differences listed below are based on what we know about THC and CBD from human and animal studies. They’re the ways we can reasonably expect the effects of balanced strains to differ from THC-dominant strains based solely on their THC:CBD ratios. The presence or absence of other compounds will likely influence the effects of specific strains and products. The list below should be viewed as a basic introduction to plausible differences between balanced and THC-dominant strains. It should not be considered a definitive guide to how every single strain will affect you.

You May Be Less Likely to Experience Anxiety With CBD Strains vs. THC-dominant Strains

Studies in both humans and animals indicate that CBD can have anti-anxiety effects. Studies in humans have observed that CBD can diminish the anxiety provoked by a stressful situation (like public speaking) or the paranoia and cognitive impairment provoked by THC administration. Laboratory studies in animals also generally find that CBD reduces behavioral measures of anxiety.


How cannabidiol (CBD) works for treating anxiety

There seem to be two important reasons for this. First, CBD diminishes THC’s ability to activate CB1 receptors, which is critical for many of the core components of the cannabis high. For some people, this includes anxiety or paranoia (especially with high doses of THC). Second, CBD can exert direct anti-anxiety effects through its influence on other receptor systems in the brain. CBD’s ability to activate specific serotonin receptors in the brain seems to be related to some of its anti-anxiety effects. (The serotonin system is a common target of some prescription drugs commonly used to treat anxiety).

CBD receptor systems

Figure 3: CBD interacts with many different receptor systems in the brain. It interacts with cannabinoid receptors indirectly by interfering with THC’s ability to activate them. CBD directly activates many other receptor types in the brain, including opioid, dopamine, and serotonin receptors. Its effects through those receptor systems may allow it to treat a variety of medical ailments. (Amy Phung/Leafly)

You May Experience Less Short-Term Memory Impairment

Reading book

A hallmark of the THC-induced high, especially at higher doses, is short-term memory impairment. Studies in humans have found that certain memory deficits caused by THC consumption are diminished by CBD. For example, a 2010 study examined the effects of smoked cannabis on memory. Intriguingly, this study assessed regular cannabis consumers and allowed them to ingest their own cannabis. Both cannabis and saliva samples were subsequently used to measure THC and CBD levels.

Participants were split into two groups based on the THC and CBD levels that researchers measured in their samples. Some were smoking what we’re calling THC-dominant strains, which lack significant levels of CBD, while others were smoking balanced THC/CBD strains. On average, the THC content was similar in both groups, but the cannabis consumed by those smoking balanced strains also contained CBD. The result: those who smoked balanced strains did not display the memory impairment seen in the THC-dominant strain consumers.


How Does Cannabis Affect Your Memory?

Another human study examined the effects on memory of oral consumption of pure THC and CBD. Consumption of only THC resulted in memory impairments, as expected. When participants were given CBD prior to THC consumption, some memory deficits were diminished, but not others. Thus, CBD won’t simply block all of THC’s effects. Some may be diminished while some are not. The specific effects will depend on the precise THC:CBD ratio, method of consumption, and presence of other compounds, such as terpenes.

You May Be Less Likely to Get Sleepy, and More Likely to Feel Alert

Pouring latte art into the cup

It is well established that THC can have sedative effects, and small studies in humans have found that CBD can counteract them. Pure THC given on its own tends to have sedative effects, while pure THC and pure CBD given in combination tends to produce increased wakefulness. Animal studies are generally consistent with these findings: administering pure CBD to rats can increase wakefulness and decrease REM sleep.

It’s possible that CBD’s effects on wakefulness depend on dose. Both human and animal studies indicate that pure CBD, given alone or in combination with pure THC, has anti-sedative effects at low-to-moderate doses. Small human studies where people have been given very large doses of pure CBD have been mixed, with some finding sedative effects and others finding no effects on wakefulness.


Cannabis and sleep: 9 things to know about your herbal nightcap

Consuming a commercial strain should be equivalent to receiving a low dose of CBD, so you may be less likely to experience sedation by consuming a balanced strain that contains both THC and CBD. This is also what we expect based on our knowledge that activating the CB1 receptor promotes sleep. Remember, CBD diminishes THC’s ability to activate CB1 receptors. This is another example where one of THC’s potential side effects (sedation) will likely decrease in the presence of CBD.

Lastly, it’s worth mentioning that it’s still possible that some CBD-containing drugs and high-CBD (hemp) strains have sedative effects. This could be caused by compounds other than CBD, such as the terpene myrcene, which can be present at significant levels in certain strains. So, while knowing the THC:CBD can tell you a lot about the potential effects of different strains, it may not always be a surefire guide to predicting exactly how a strain will affect you.

You May Be Less Likely to Get the Munchies

Hunger has long been one of the most famous side effects of cannabis consumption. For some, it’s a wonderful part of the cannabis experience. For others, it’s a highly undesirable side effect that makes them leery of consumption.

This is another effect driven by THC’s ability to activate CB1 receptors. In laboratory studies in rodents, increased feeding is observed once the rodents are given THC or other compounds that activate CB1 receptors. If you prevent THC from activating these receptors, you do not see increased feeding. That’s how we know that the THC-CB1 receptor interaction is critical for this effect.


The Science of Munchies: Why Does Cannabis Stimulate Your Appetite?

Animal studies have also investigated how CBD affects feeding behavior. On its own, CBD seems to have no effect. However, in the presence of compounds that activate CB1 receptors, it blocks the increases in feeding that are observed with CB1 receptor activation alone. To my knowledge, CBD’s effects on hunger have not been studied in humans.

Given what we know about CBD’s ability to interfere with the THC-CB1 receptor interaction, we would expect balanced strains containing CBD to be less likely to give you the munchies, while THC-dominant strains should be more likely to do so. Again, it’s possible that the presence or absence of other compounds will also matter.

General effects across cannabis strains

Figure 4: Consumers will experience different effects with different products and strains. THC and CBD levels can vary widely between strains, and knowing the THC:CBD ratio can help you anticipate and remember how specific strains affect you. Based on laboratory experiments, some of the classical THC-induced effects of cannabis may be diminished in balanced strains with significant CBD levels. Ultimately, the effects of a strain will also depend on a variety of other factors. (Amy Phung/Leafly)



Whether you’re a seasoned consumer or new to cannabis, it’s worth considering the THC:CBD ratio when assessing what kind of strain is right for you. This is especially true for novice cannabis consumers who may be nervous or overwhelmed by the sheer variety of strains and products.

New consumers may want to start out with balanced strains, which not only have lower THC levels than most THC-dominant strains, but also contain CBD. Everyone’s different, and there are certainly no guarantees, but balanced THC/CBD strains should make you less likely, on average, to experience unwanted side effects like anxiety, sleepiness, or feeling “too high.”


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Englund A, Morrison PD, Nottage J, et al. Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment. J Psychopharmacol (Oxford). 2013;27(1):19-27. PDF
Farrimond JA, Whalley BJ, Williams CM. Cannabinol and cannabidiol exert opposing effects on rat feeding patterns. Psychopharmacology (Berl). 2012;223(1):117-29. PDF
Morgan CJ, Schafer G, Freeman TP, Curran HV. Impact of cannabidiol on the acute memory and psychotomimetic effects of smoked cannabis: naturalistic study: naturalistic study. Br J Psychiatry. 2010;197(4):285-90. PDF
Murillo-rodríguez E, Millán-aldaco D, Palomero-rivero M, Mechoulam R, Drucker-colín R. Cannabidiol, a constituent of Cannabis sativa, modulates sleep in rats. FEBS Lett. 2006;580(18):4337-45. PDF
Nicholson AN, Turner C, Stone BM, Robson PJ. Effect of Delta-9-tetrahydrocannabinol and cannabidiol on nocturnal sleep and early-morning behavior in young adults. J Clin Psychopharmacol. 2004;24(3):305-13. PDF
Scopinho AA, Guimarães FS, Corrêa FM, Resstel LB. Cannabidiol inhibits the hyperphagia induced by cannabinoid-1 or serotonin-1A receptor agonists. Pharmacol Biochem Behav. 2011;98(2):268-72. PDF
Russo EB. Cannabidiol Claims and Misconceptions. Trends Pharmacol Sci. 2017;38(3):198-201.

Nick Jikomes's Bio Image

Nick Jikomes

Nick is Leafly's principal research scientist and holds a PhD in neuroscience from Harvard University and a B.S. in genetics from the University of Wisconsin-Madison. He has been a professional cannabis researcher and data scientist since 2016.

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  • Michael L. Wallace Jr.

    Obviously your Science is Fugged up . As well as your ability to read THC to CBD ratios . CBD ability to counteract the effect of THC clearly means all of THC is a stimulant . Abusive misuse of any THC can result in Minor Temporary Anxiety . CBD ability to grow new brain cells in the hippocampus preventing alzheimers . Clearly means that the sedating effect is the brain draining energy from itself to focus it on new cells . The Munchies are then necessary for replenishing spent energy . Not replenishing spent energy is guaranteed discomfort .

    • Michael S. Braibish

      So – if I’m following you correctly – the munchies are essential to fueling brain growth/repairs; i.e., there’s a direct correlation between hunger and the growth of new cells. Does that mean that when I get the munchies and plow through a family size bag of Doritos and a large pizza my brain is using all that to grow? Doesn’t seem likely. To what extent are there greater dietary requirements as a result of THC/CBD consumption? What science backs your assertions? I’d like to see the research.

      • Michael L. Wallace Jr.

        Not all foods apply. Certain Nutrients of Foods are required. No scientific research just Common Sense. Something you clearly lack. Please go be an ASOLE to someone else.

        • Maria L.

          Mr. Wallace, the number one rule of engaging in a persuasive argument is to be respectful and state the facts. You may have some interesting points to make, but Insults detract and do not make your point of view credible. If you want readers to take your opinion seriously, try being respectful while staying strong in knowledge and passion, but not in emotion. Finally, supportive documentation strengthens your case and makes you credible. Remember: facts are more convincing than opinions.

    • Julzeric

      Why read up well document scientific articles when you can go straight to the comment section and get an on-point dose of bro-science

  • Dr. C

    Each person has a unique endocannabinoid profile as well; how high you feel when consuming THC may be directly related to how CB 1 receptors you have in your brain.

  • Karen Ferrandi

    Im at an impasse..over the last 6 months I have tried everything from starting with CW Stanley Bros) tincture, advancing to their 5000 which didn’t seem to make me feel any less anxious. I suffer from early morning severe anxiety which gets better as day goes on but generally till 5-7 pm im not calm as I would like.,I suffered with IBS, not IBS-D or IBS-C for over 30 years but just pain attacks left lower groin…once it was relentless for 24 hours. Since starting with the various CBD the IBS pains barely returned..once or twice mildly severe but under2 hours..havent had one now at all in several months. So def CBD works for me for that. Now I then felt my anxiety was still bad..ALWAYS upon awakening though must say from a 10 every day it ranges from a 7-5 and as day progresses it it gets better. I am healthy otherwise, proper weight, just cannot shake the anxiety. Since I cannot get Harlequin in my state my family sends it, it seems perhaps the entourage effect would be better. Its still same …I am grateful to function but want to wake up , take a couple puffs or a dropper of tincture and feel calm..this hasn’t happened. I do 25 minutes meditation/deep breathing every morinng..this is over3 weeks now..without helps to get me going. These are what I tried: CW as I told above from Stanley Bros…OPen vape 1- bluepackage, Green Roads CBD oil tincture 350 mgs, CBD terps Sour Diesel added to my CBD, HUXTON vape (ZEN strain) Herbal Renewels strong hemp extract 1G golf label hemp oil paste, no effect noticeable, Pure Science cbd hemp 700 mgs ( no noticeable effect) Hemp PEACE choc mint ( not very effective) Shelter From The Storm Jetty Exrtacts , Alternate Vape 7 citrus blend ( 100mg) vape oil , Green Road CBD syrup 100 mgs ( awful taste ) and a couple others sent by children with very low THC no name was enclosed. I am 73, look and feel 55, health excellent, but cannot get rid of this daily early anxiety that lingers hours. I DO NOT WANT A HIGH, nothing psychotropic. So im sorta at wits end..any suggestions which HIGH CBD or maybe a ration of very low THC to CBD for entourage effect. Im member of ROC, talk to Leafly a lot..I just want to RELAX and be chilled for my days. I have no pain or anything but miserable anxiety and depression! THANK YOU FOR READING! PLEASE help if you can .

    • John Levene

      Have you seen this video on meditation?

      Just watching it helped me get better control of my anxiety.

      Also, green roads has much higher doses of oil. I personally like the 100mg but the 300mg, 600mg or 1,000mg might help you more.

      Hope that helps a little.

      • Karen Ferrandi

        Thank you kindly for your sorry took so long to thank you as was numerous severe health issues with several friends and family. I did use Gren Roads and it was ok.I am now vaping with HARLEQUIN (name of the strain) which I get from my son in Arizona..has 1-1 ratio. No IBS attacks that have been severe since and also my anxiety is way less..from a 10 to a 3 but I do take a very small dose of Lexapro at night ( 2.5 mgs) I break a 20 mg pill in quarters..and 10 mgs or sometimes 5 mgs in day of Valium . I wish I could eliminate the pharmaceuticals and I hope in next 3 months to be able to do so. Again my regrets on delay and many thanks!

  • Linda DeClercq

    I found this very informative and helpful! It accurately represents my response – in general – to MMJ

    • jordan Wilson

      I got relief from PTSD,pains and depression from meds and hemp oil i got from Dr Mark Donald via his number (313) 923-7690

      • Boldwin Samuel

        Dr Mark is for real he cured out my pains and anxiety with his THC/CBD Cannabis Oil , i appreciate and vouch for him 100% Thanks to you John for linking me to the right source, am now cancer free after a 3 month dose of 60grams THC/CBD Cannabis from Dr Mark,my family fully appreciate you Mark ,talk to him at 313- 923-7690

  • Andrew Jackson

    Have you ever felt sick to your stomach after taking CBD oil?