Why Does the 1:1 CBD:THC Ratio Seem to Work So Well?

Today, we’re looking at what’s so special about the 1:1 ratio of CBD:THC. Many medical marijuana patients find this ratio nothing short of miraculous. But why? This article dives into some studies into the ratio and why it’s effective.

As well as reading this article, we also recommend that you speak to your physician while you’re applying for your medical marijuana card to get their dosage recommendation for you:

Table of contents
  1. Sativex and the Initial GW Pharmaceuticals Studies
  2. Is Sativex Available for Patients in the US?
  3. Is Epidiolex Available for Patients in the US?
  4. THC and CBD Balance Each Other Out
  5. How Do THC and CBD Interact?
  6. What About the Other Cannabinoids?
  7. How Do the Effects of Different CBD:THC Ratios Vary?
  8. Fibonacci Sequences?
  9. Conclusion
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Of this, there is no doubt: the “best ratio” varies from person-to-person and condition-to-condition. Some types of cancer require high amounts of THC in order to treat properly, whilst other types of cancer require more cannabidiol (CBD) than (THC), especially with conditions like oestrogen-positive breast cancer, where too much THC may cause the cancer to grow. Other factors that affect how one responds to specific cannabinoids include age, gender, and to some extent weight. You can see read more about different cannabinoids and terpenes in our handy table here.

However, for many people, the magic ratio of THC to CBD is 1:1. Why is this? We look at a few reasons why.

Sativex and the Initial GW Pharmaceuticals Studies

In the UK, there is a product named “Sativex“, which is produced by the same people who make Epidolex – GW Pharmaceuticals. Sativex contains a THC:CBD ratio of approximately 1:1. Whether or not this ratio was necessarily more effective than others, we do not know for definite, but the people who took part in the initial studies said that they preferred the 1:1 ratio as it was most tolerable, whilst at the same time still helping to prevent or reduce pain, stiffness and spasms. The 1:1 ratio does not have as many psychoactive effects as strains or products high in THC, and as such this means that the everyday life things get done without feeling in a haze (pun intended) or a fog.

Chemical formula THC; tetrahydrocannabinol; THC isomer.
Tetrahydrocannabinolic acid (THCA) isomer – chemical structure. By RobinLeclercq. Source
Is Sativex Available for Patients in the US?

No, Sativex is not available on prescription for patients in the US. You can, however, get a medical marijuana card and purchase a 1:1 THC:CBD product. GW Pharmaceuticals are able to create precise ratios as they have a laboratory and can afford to pay the specialists required to run an advanced one. However, what differences in quality there are between GW Pharma’s version and one produced by another company is not known. We are sure there must be at least a couple who can compete!

Sativex is the trade name for nabiximols. A systematic review in 2014 by the American Academy of Neurology found that nabiximols was ‘probably effective’ for spasticity, pain, and urinary dysfunction, but wasn’t supported for tremor. Naboximols was also successful in treating cancer pain resistant to opioids, but the primary endpoint was not met in Phase III. Essentially, Phase II trials showed that cannabis was effective for cancer-related pain, but Phase III trials did not. This suggests that more research needs to be done, and perhaps look deeper into

Molecular Structure - CBD
CBD molecular structure.
Is Epidiolex Available for Patients in the US?

Epidiolex is a CBD-based drug that is available for prescription in the US. It is used to treat seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients 2 years of age and older. Epidiolex is a Schedule V drug, as the FDA has approved it and contains less than 0.1% THC. Yet, CBD derived from cannabis flower is deemed a Schedule I drug if it is not approved of by the FDA. Only CBD derived from hemp stalks is legal, and any product made using it will need to contain 0.3% or less of THC for it to be legal. Aside from Epidiolex, there are no other CBD products that have been given DA approval.

relax if you've had too much cannabis

THC and CBD Balance Each Other Out

CBD seems to “balance” out the high THC gives when used in equal ratios to each other, whilst at the same time allowing the THC to provide its own pain-killing, antiemetic and appetite-stimulating properties. THC and CBD seem to work in tandem with each other, and can possibly even bolster each other’s strengths, whilst also buffering some of THC’s psychoactive effects. The theory is that, as CBD does not cross the blood-brain barrier (BBB) and is a partial antagonist of the CB1 receptor, THC helps CBD pass the BBB and allow it to take effect properly. This is just a theory, however, and one that doesn’t explain everything about CBD and THC and how they interact. However, there does seem to be some sort of relationship between CB1 receptors in the brain and the gut and CB2 receptors found on immune system cells.

Download Free Guide to CBD
Download Free Guide to THC
How Do THC and CBD Interact?

The precise ins-and-outs of how various cannabinoids and terpenoids interact and work with one another is not precisely known, but it seems CBD may prolong the amount of time THC spends in the liver all the while regulating the THC’s psychoactivity when used in equal ratios. This could be why many high-THC, low-CBD strains can be powerful but don’t usually have long-lasting effects. Such strains also tend to contain tetrahydrocannabivarin (THCV), which does block THC in low doses and is psychoactive in and of itself in high doses – the lack of CBD and high amounts of THC and THCV may give a clue as to why there is no “ceiling” to this type of plant. High-THC, high-CBD strains tend to last longer but tend to leave people couch-locked.

What About the Other Cannabinoids?

To just look at CBD and THC on their own is far too simplistic. We also ought to take into account other cannabinoids we are ingesting when using cannabis, as these will all contribute to the overall effect. We should also look at terpenes and terpenoids as well. A 1:1 CBD:THC ratio containing mostly beta-caryophyllene and limonene is going to have markedly different effects from a product with the same 1:1 CBD:THC ratio but containing terpenes like linalool, humulene and myrcene. It is also important to note that there are some structural similarities between some kinds of terpenes and cannabinoids in the cannabis plant, and that cannabinoids have terpene-like profiles (and vice-versa). Beta-caryophyllene is perhaps the most popular example of the ECS-affecting properties of terpenes and terpenoids, but there are certainly others. These terpenes interact with cannabinoids, and may even have an effect on the overall cannabinoid profile as well!

How Do the Effects of Different CBD:THC Ratios Vary?

Equal THC:CBD ratios may produce some limited psychoactive effects. People often want some psychoactive effect for therapeutic reasons, as THC can help beat or “forget” about the pain. High-CBD, low-THC strains produce few if any psychoactive effects for most people, although some may still be felt. CBD still imparts an effect even if it is not psychoactive in the “traditional” sense. Low-THC, high-CBD strains are seen as particularly useful for children or those particularly sensitive to THC, as they are not as psychoactive and still have enough THC in it for therapeutic reasons. However, this is not always the case, and many people may be doing themselves a disservice by going for high-CBD alone, especially if they have a specific condition where higher (though not necessarily psychoactive) amounts of THC may be needed.

Terpenes; terpenoids; chemotypes; cannabis; marijuana; Chemotypes found in Melaleuca quinquenervia.
Chemotypes found in Melaleuca quinquenervia. Source
We Would Like to Mention Something About the “Psychoactivity” of Cannabis

Depending upon the strain and cannabinoids taken, most people who use medical marijuana report feeling euphoric, relaxed, giggly, chatty, sleepy, happy etc. One reason why many people enjoy cannabis is because it has these effects whilst at the same time letting them remain functional when the dosage is right. You tend not see pink elephants and wizards casting magic spells when using cannabis, unless you have used an extremely strong, high THC edible and you have not “trained” yourself to handle high doses of cannabis, or if you are unfortunate to suffer from a condition that causes psychosis (e.g. schizophrenia, bipolar disorder). And even then, you are more likely to fall asleep than see pink elephants.

This brings up another issue about cannabis’s psychoactive constituents. After all, if CBD is having a physiological effect, i.e. it’s helping you feel sleepy and relaxed, giving you a “jolt” of energy and focus (not unusual in slarger amounts) and so on, could it not be said that CBD is psychoactive to some extent? Sure, you probably won’t get the sort of euphoric effects usually associated with THC, but to say that CBD has no physiological and psychoactive effect whatsoever is simplistic (and plain wrong – CBD definitely does have physiological effects). You can read more on how CBD works here.

michigan marijuana

Fibonacci Sequences?

Fibonacci numbers and sequences can be found everywhere in nature. The simplest sequence runs 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144 (the next number will be 144+89) … The Golden Ratio – or phi – which is the number 1.618, is related to this phenomenon. As this number is found throughout nature, could it be possible that the reason why the 1:1 THC-CBD ratio works so well is because it works in harmony with the human body?

This could be a possibility, but it is a bit of a stretch. However, what is not a stretch is that the cannabis plant produces its cannabinoid and terpenoid content to help “balance” it out, just like our own bodies produce certain hormones when balancing out the effects of other ones. So for example, if the plant is producing too much THC, it will produce a certain amount of CBD and/or other cannabinoids and terpenoids in order to “balance” out the THC. Whilst genetic manipulation has removed this tendency to some extent, it is by no means removed entirely – we can’t completely control nature yet, and in fact many breeders have been selecting for these traits in order to keep certain genetic pools alive. This is great for cannabis and cannabinoid-terpenoid diversity.

Fibonacci spiral; formula to get the golden number, phi.
Fibonacci sequence and formula for phi, the golden ratio. Image by Rafael Javier from Pixabay. Pixabay License.


Though the 1:1 THC:CBD ratio is popular, it is by no means the be-all-and-end-all to cannabis as a medicine. The 1:1 ratio gives a good place to start for many people, though. and will help make you think of cannabis in terms of genetics, cannabinoids and terpenoids rather than strain names. At the moment, mostly what people have to rely upon is not standardized, and is based upon names. On top of this, growing in different environments and generations of a particular strain may yield different cannabinoid-terpenoid-flavonoid profiles, so it can be very difficult to say that a particular strain is better suited than another for a particular condition. Yes, there are patterns to be found in specific strains, but the name alone will not necessarily give an indication of the plant’s chemotype. GW Pharmaceuticals are able to produce consistent 1:1 CBD:THC ratios (or, more accurately, 51:49) as they have cultured specific cannabis plants in order to prevent variation across generations. At the moment, this is not standard practice amongst most growers, whether due to cost or otherwise (and there is still lots of value in breeding cannabis for variation in the gene pool).

Download Our 1 Pager Guide to Dosing Medical Marijuana

Want to know what kind of medical marijuana might help your condition? Check out our conditions page and apply for your MMJ card online today!




Written by
Dipak Hemraj
Dipak Hemraj

Dipak Hemraj is a published author, grower, product maker, and Leafwell’s resident cannabis expert. From botany & horticulture to culture & economics, he wishes to help educate the public on why cannabis is medicine (or a “pharmacy in a plant”) and how it can be used to treat a plethora of health problems. Dipak wants to unlock the power of the plant, and see if there are specific cannabinoid-terpene-flavonoid profiles suitable for different conditions.

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