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what is an effective dose of cbd

We Asked a Scientist: What’s the Right Dose of CBD?

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This article is sponsored by Tilray, one of the largest and most sophisticated producers of medical cannabis in the world. Tilray is dedicated to providing safe, consistent, and reliable products to patients and furthering clinical research.

As research into the medical applications of cannabis compounds steadily increases, scientists and doctors are shedding new light on how cannabinoids interact with not only the human body, but with other cannabinoids. New studies are providing further insight on why these substances work, how they can be used most effectively, and what new applications they may have in the future.

We sat down with Nick Jikomes, Leafly’s in-house neuroscientist, to learn about what researchers are learning about the cannabinoid CBD, and how different doses can be put to use in treating a variety of conditions.

Nick Jikomes (Julia Sumpter/Leafly)

Tilray: Let’s start with the basics: what is CBD, exactly?

CBD, or cannabidiol, is one of the major cannabinoids found in Cannabis—typically the second most abundant after THC. It’s like THC in that it’s a plant cannabinoid with a similar chemical structure, but it’s also very different in terms of physiological effects.

The most obvious way that it’s different is that it’s non-intoxicating—CBD doesn’t get you high the way that THC does. There are also interactive effects between THC and CBD. They can enhance each other, but they can also get in the way of one another. Some of those interactions have potentially interesting medical applications.

What do we understand about that relationship between THC and CBD, and what are we learning about it?

The first thing to understand is how each one interacts with receptors in the nervous system. The major receptor in the endocannabinoid system (ECS) responsible for the psychoactive effects of cannabis is CB1, a receptor found predominantly in the nervous system. For classic psychoactive effects to be felt, THC needs to bind to that receptor and activate it.

CBD also interacts with the CB1 receptor, but in a different manner. It doesn’t activate that receptor; in fact, it makes it harder for the receptor to be activated by other compounds. CBD is essentially getting in the way of THC’s ability to bind the CB1 receptor, which is why the presence of CBD has a significant impact on the psychoactivity of THC-containing products. This is why the ratio of the two compounds is important for anticipating the effects of cannabis products.

The other thing to keep in mind is that most compounds, CBD included, interact with many different receptor systems. So, it’s not just the relationship with THC that’s interesting; CBD is interacting with many other receptors and having many different effects through those systems.

CBD is available in numerous forms, including liquid drops. (Courtesy of Tilray)

CBD is recommended for a wide range of symptoms and conditions—are there instances where you’d want some CBD with your THC, and others where you want just CBD?

Basically, yes. CBD may reduce many of the unwanted side effects of THC, such as short-term memory impairment and anxiety, which are more common at higher doses of THC. Often the more CBD you have relative to THC, the less of those things you should expect.

While THC and CBD have different pharmacological properties, they can both have similar physiological effects, probably acting through different mechanisms. For instance, both compounds can have analgesic and anti-inflammatory effects; they may act through different mechanisms, so having THC and CBD could potentially enhance an outcome surrounding pain relief.

Are we at the point in research where we can better understand, based on the condition a patient might have, what could be the most useful blend? Or is there still some trial and error involved for patients finding what is going to work best for them?

I don’t think the clinical evidence is currently at a point where you can say you want this particular ratio for this particular condition to a specific patient. If you are a patient who finds that a 1:1 THC to CBD blend is perfect for you, that’s great. But you’re most likely going to have to get there through some trial-and-error, and when you do, there are good reasons to think that blend won’t be perfect for you forever.

That’s because people’s physiologies change over time, including the ECS and how densely receptors are expressed in the brain and the body. These things change over the lifetime of an individual, and so the optimal ratios and doses of these compounds, whatever they may be, are probably going to change as well.

Medical cannabis providers carefully measure CBD for dosing. (Courtesy of Tilray)

It sounds like the proper dose, in the long run, can be kind of a moving target?

It can, and that’s one reason to be very cautious about being overly prescriptive about doses and ratios. There’s an interesting study on this topic looking at THC in mice, and the results suggest that the same dose of the same compound (THC, in this case) has very different behavioral and cellular effects depending on the age of the subjects.

This is a very common thing in the world of pharmaceuticals—different doses of a drug can have different effects. With substances that bind to a lot of different receptors, like CBD, there’s often a sweet spot around a mid-sized dose. That means you can’t necessarily expect the substance to be twice as strong if you double the dose—in fact, you might see the opposite.

And that article points out that there are also different conditions for which different dosages are effective?

Exactly. And that’s likely because CBD is binding to many different receptors throughout the body. At a fairly low dose, it will mainly hit the receptors it has the highest affinity for, or that are the most densely expressed. At higher doses, those receptors can become saturated, so the remainder of the CBD will interact with other receptor systems, and that’s where you may start to see different effects.

Are we starting to see a ceiling on effective dosages of CBD?

It depends on the condition you’re trying to treat. If you’re using CBD for anxiety, there may be that sweet spot, a middle dosage, that has the best effect, and it can become less effective if you increase the dose.

In epilepsy, that hasn’t been seen yet. They’re using very high doses in that treatment, and I don’t think anyone has yet observed a diminishment in effect as the dose goes up. But in most clinical studies looking at things like epilepsy, they’re using oral CBD (given in pill form) at very high doses – hundreds of milligrams per day. CBD has very low oral bioavailability, meaning that only a fraction of the CBD one would take in pill form ends up in the bloodstream and hitting the relevant receptors in the nervous system. So when thinking about dosage, it’s also important to consider the route of administration.

So the route of administration can impact how much CBD ends up in someone’s system?

That’s right. Again, CBD has very low oral bioavailability. So if you swallow CBD in pill form, only a fraction of that CBD will end up making it into the bloodstream and exert an effect in the brain or elsewhere in the body. Different routes of administration, such as vaporization, sublingual tinctures, or transdermal patches, provide a more direct route for CBD to enter the bloodstream. This probably allows for a larger proportion of the CBD in those products to enter the bloodstream. So, people interested in CBD products may want to consider experimenting with different routes of administration. A given amount of CBD in pill form could may not lead to the same outcomes as an identical amount taken via another route.

Leafly’s in-house neuroscientist Nick Jikomes explains how different cannabinoids interact, why different conditions benefit from different doses of CBD, and more.

What Dosage of CBD Should You Take?

Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

A bottle of CBD oil and a medicine dropper

Iryna Veklich / Getty Images

CBD is available in a number of different formulations including creams, tablets, oils, and gummies. These can vary in terms of their ingredients as well as dosages, and there is not a great deal of research available on what dose might be beneficial or safe to treat certain conditions.

Cannabidiol (CBD) is the second most abundant cannabinoid found in marijuana. Unlike tetrahydrocannabinol (THC), CBD does not have psychoactive effects. Interest in the use of CBD for health purposes has grown tremendously in the last few years.

CBD is believed to have a range of positive physical and mental health effects. Because of this, it has become increasingly popular as a way to alleviate everything from anxiety to sleep disorders.

In order to determine if CBD is right for you, it is important to consider its potential benefits, side effects, and available research on safe dosages.

Possible Benefits

CBD is just one of hundreds of different compounds found in the cannabis plant. While cannabis has been used in holistic medicine for many years, only recently have researchers begun to explore some of the medicinal purposes for CBD and other cannabinoids.

While further research is still needed, there is some evidence that CBD may have some beneficial mental health effects. These include:

  • Alleviating depression: Some research also indicates that CBD may be useful as a treatment for depression. Studies suggest that the cannabinoid might have an influence on how the brain responds to serotonin, a neurotransmitter that plays a key role in mood.   People with depression sometimes have a low level of serotonin, so CBD may help the brain use available serotonin more effectively.
  • Improving sleep: While the reasons are not entirely understood and require further research, CBD also appears to have potential as a treatment for sleep problems. For example, one study found that people who took CBD also reported improvements in the quality of their sleep.  
  • Reducing anxiety: Anxiety is one of the most common types of mental health conditions, affecting almost 20% of American adults each year. Research suggests that CBD may help alleviate acute symptoms of a number of anxiety-related conditions including generalized anxiety disorder, obsessive-compulsive disorder, and social anxiety disorder.  

In addition to the mental health benefits, CBD may also have therapeutic benefits for a range of other conditions. The World Health Organization suggests that CBD may have beneficial effects in the treatment of:  

  • Alzheimer’s disease
  • Arthritis
  • Cardiovascular disease
  • Diabetes
  • Infection
  • Inflammation
  • Multiple sclerosis
  • Nausea
  • Pain
  • Psychosis

It is important to remember that these benefits have not yet been conclusively proven. More research is needed to determine the role that CBD might play in the treatment of different disorders and health conditions.

Research

There have been a number of studies that suggest that CBD may have a number of different physical and mental health uses. However, more research is still needed to better understand the substance’s potential applications and possible long-term side effects.

A 2019 comprehensive review published in The Lancet Psychiatry looked at previously published studies.   The review ultimately concluded that there was little evidence to support the use of CBD for mental health purposes and suggested that more research is needed in order to substantiate its use to treat symptoms of conditions such as anxiety, depression, and insomnia.

It is important to remember that this doesn’t mean that CBD isn’t effective. Many of the studies that were included in the review were small, had few participants, and were not randomized controlled trials.

This suggests that more research involving more participants and well-designed studies is needed in order to better understand if, how, and why CBD works.

While its effectiveness is still up for debate, one 2017 review found that it was a relatively safe option.   While it is important to remember that there is still a great deal we don’t yet know about CBD and its effects, it is something that you might opt to try to see if you experience any benefits.

How Much Should You Take?

The dosages used in research studies vary and there is no consensus on how much should be used for specific conditions. If you do decide to try CBD, it is also important to note that there is no universally agreed upon dose. Research also suggests that people may respond differently to various dosages, so the amount that is right for your needs might vary.

CBD Dosages

Some dosages that have been used in research studies for different conditions include:

  • Anxiety: 300 to 600 mg  
  • Bowel disease: 10 mg per day  
  • Cancer-related pain: 50 to 600 mg per day  
  • Parkinson’s disease: 75 to 300 mg per day  
  • Poor sleep: 25 mg per day  
  • Psychosis: 600 mg per day  

One 2020 review of studies found that participants showed improvements in anxiety levels after single doses of CBD ranging from 300 to 600 mg.   Such results indicate that the CBD may hold promise as a treatment to alleviate symptoms of acute anxiety.

It is important to remember that you should always talk to your doctor before using CBD if you have symptoms of a serious mental or physical health condition. CBD could potentially worsen symptoms or interact with other medications you are taking.

Looking at the dosage information for the CBD product that has been FDA approved can also be helpful. For Epidiolex, an FDA-approved cannabis-derived medication used to treat seizures in people with certain types of epilepsy, the starting dosage is 5 milligrams per kilogram of body weight. This dose can later be increased to 5 mg per kilogram of body weight twice a day.

Other CBD products are not FDA regulated and do not have officially recommended dosages. This can make it difficult to determine how much you might need, but there are some things you can consider that might help.

  • Assess your sensitivity to CBD: Your individual ability to tolerate CBD can also play a role in determining how much you need. If you are very sensitive to the effects of CBD, you should take a small dose. Some people may find that they are not as affected by the substance, so they may need to take a larger dose to notice any beneficial effects.
  • Consider individual factors: When you are trying to decide how much CBD to take, there are a number of factors you should consider. These include the formulation and concentration of the capsule, oil drops, or gummies you are taking, the symptoms you are treating, and your age, sex, weight, and overall health. Generally, people with heavier bodies need to take a little more to achieve the same effects. Men may need a larger dose, while older people may need less.
  • Consider the symptoms you’re treating: The symptoms you are trying to alleviate can also play a role in the CBD dosage you need to take to see results. In one study, participants who took 25mg of CBD each day had improved sleep quality, although the results were not consistent.   However, you might find that you need a lower or higher dose if you are treating another type of condition.
  • Try a dosage calculator: Researchers note that while the variety of dosing strategies and formulations make it difficult to determine efficacy, there are a number of online “dose-calculators” available online (such as mydosage.com) that are designed to help people choose the correct dose.   The accuracy of such calculators is difficult to assess, but it may be a good place to start.

Before you try CBD, discuss your plan with your doctor. They may be able to recommend a dose and help you better understand any potential risks, complications, side effects, or interactions you might experience.

Start With a Low Dose

Unless your doctor recommends a specific dose, start by taking 10 to 20 mg a day. Take this for a week to ensure that it is well-tolerated and that you don’t experience any unwanted effects or an allergic reaction.

If this dose does not have the desired effect, try increasing in increments of 5mg each week until the desired amount is reached.

In studies, amounts vary from as low as 20 milligrams per day to up to 1,500 milligrams (mg) per day. The World Health Organization reports that dosages in clinical research studies typically range between 100 and 800 milligrams per day.  

Is It Possible to Take Too Much?

So what is the maximum amount of CBD you should take? Researchers have found that 600 mg per day appears to be safe, but one study suggested that doses of up to 1,500 mg a day are safe and tolerated well.  

However, it’s important to remember that research is still in its infancy and experts do not yet fully understand the potential long-term impacts of CBD usage. For that reason, you should always discuss your CBD use with your doctor.

Starting at a lower dose and working your way up to the amount you need may be the best ways to avoid taking too much.

How to Take CBD

The amount of CBD found in a product may depend on different factors, including the formulation and method of administration. CBD products are available in a number of different forms including oils, capsules, tablets, nasal sprays, and gummies.

One of the most popular ways to take CBD is as an oil. Such products are made by combining CBD with some type of carrier oil, such as coconut oil. Some more recently developed products include dietary supplements, foods, beverages, lotions, salves, and cosmetics.

The type of CBD product you choose may depend on what you are trying to treat. If you are looking for general mood improvements, a dietary supplement might be a good option.

If you are targeting specific symptoms of a condition, taking an oil, capsule, or gummy might be a better way to obtain a higher, more concentrated dose.

Topical applications may produce localized effects, but they are unlike to have any mental health benefits.

What Kind Should You Take?

It’s also important to remember that many products don’t contain just CBD on its own. There are three types of CBD available:

  • Isolate contains CBD and only CBD.
  • Broad-spectrum contains CBD and other cannabinoids, but not THC.
  • Full-spectrum contains CBD, THC, and other cannabinoids.

It may be helpful to take a broad-spectrum product since research suggests that CBD’s effects may be most beneficial when taken in conjunction with other cannabinoids, a phenomenon known as the entourage effect. CBD may also help mitigate some of the effects of THC.

Side Effects

While CBD is generally well-tolerated, this does not mean that you won’t experience any side effects.

Some of the most common side effects that people experience when taking CBD include:

  • Appetite changes
  • Diarrhea
  • Nausea
  • Dizziness
  • Stomach upset
  • Weight changes

Some recent research has generated concerns over the safety and potential long term effects of CBD. One study involved giving mice an equivalent of the maximum dose of the CBD medication Epidiolex, which is used to treat certain forms of epilepsy. The results indicated an increased risk for liver damage as well as concerns over its interaction with other medications.  

Safety

It is also important to remember that CBD products are not regulated by the U.S. Food and Drug Administration (FDA). Some manufacturers make unproven claims about the uses and efficacy of their products. There is also concern about the quality and safety of the products themselves.

One report by the Centers for Disease Control and Prevention (CDC) indicated that a number of people experienced negative unwanted side effects due to CBD products that contained synthetic CBD, although the products were not labeled as containing such ingredients.  

Mislabeling appears to be a fairly common problem with CBD products. In one study, 70% of the CBD products that were sold online contained significantly more of the psychoactive ingredient THC than the label indicated.  

Federal law prohibits the sale of products that contain more than 0.3% THC. States laws also vary, so you should always check with your state before buying CBD products online.

A Word From Verywell

If you do decide to take CBD to alleviate an acute or chronic condition, remember that the amount that you take will depend on a variety of factors. Finding the right dosage often takes some experimentation and adjustments. Starting with a low dose and then gradually increasing the amount you take until you achieve the desired effects is the best approach.

CBD holds promise as a treatment for a range of conditions, but how much should you take? Learn more about CBD dosages for different purposes.