What Is CBD Oil?
This cannabis extract may help treat nerve pain, anxiety, and epilepsy
Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman’s World, and Natural Health.
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Meredith Bull, ND, is a licensed naturopathic doctor with a private practice in Los Angeles, California.
Cannabidiol (CBD) oil is an extract from hemp plants called Cannabis indica and Cannabis sativa . You might be more familiar with cannabis plants because they are grown for marijuana. However, CBD is not the same thing as marijuana.
CBD oil contains CBD that’s mixed with a base (carrier) oil, like coconut oil or hemp seed oil. These are called tinctures. You can get tinctures in different concentrations. The oil can also be put into capsules, gummies, and sprays.
People who support using CBD oil say that it can treat pain and anxiety; can help stimulate appetite and may help manage some types of seizures.
This article goes over what CBD is used for, the possible side effects, and what you should look for if you choose to buy CBD.
CBD vs. Marijuana
CBD is one component (called a cannabinoid ) that’s found in a hemp plant. Marijuana is a separate plant but it’s from the same species that hemp belongs to. Marijuana has CBD and hundreds of other compounds in it.
The main difference between hemp plants and marijuana plants is how much of a compound called tetrahydrocannabinol (THC) is in them. Hemp is grown to have less than 0.3% THC, while marijuana has more.
THC is what’s responsible for the psychoactive effects of cannabis—in other words, it’s what makes you feel “high.”
CBD oil generally does not have THC in it; however, a very small (trace) amount might be in products sold in certain states.
What Is CBD Oil Used For?
We’re not sure exactly how CBD works. Unlike THC, CBD doesn’t have a strong connection with the molecules in the brain that THC binds to create psychoactive effects. These are called cannabinoid receptors.
Instead, CBD works on other receptors, like the opioid receptors that help control pain. It also affects glycine receptors that control a brain chemical called serotonin which helps control your mood.
People that support the use of CBD claim that CBD oil can treat a variety of health problems, including:
- Chronic pain
- Drug use and withdrawal
- High blood pressure
- Muscle spasms
- Poor appetite
As CBD has gained popularity, researchers have been trying to study it more. Still, there has not been a lot of clinical research to look for evidence in support of these health claims.
CBD is not a safe option for everyone. Talk to your healthcare provider if you want to try it for managing a health condition.
A 2015 review of research that was published in the journal Neurotherapeutics suggested that CBD might help treat anxiety disorders.
The study authors reported that CBD had previously shown powerful anxiety-relieving effects in animal research—and the results were kind of surprising.
In most of the studies, lower doses of CBD (10 milligrams per kilogram, mg/kg, or less) improved some symptoms of anxiety, while higher doses (100 mg/kg or more) had almost no effect.
The way that CBD acts in the brain could explain why this happens. In low doses, CBD might act the same as the surrounding molecules that normally bind to the receptor that “turns up” their signaling.
However, at higher doses, too much activity at this receptor site could produce the opposite effect.
There have not been many trials to look at CBD’s anxiety-relieving effects in humans. However, one was a 2019 study published in the Brazilian Journal of Psychiatry.
For the study, 57 men took either CBD oil or a sugar pill with no CBD in it (placebo) before a public-speaking event.
The researchers assessed the participants’ anxiety levels using measures like blood pressure and heart rate. The researchers also used a reliable test for mood states called the Visual Analog Mood Scale (VAMS).
The men who took 300 mg of CBD oil reported less anxiety than the men who were given a placebo; however, the men who took 100 mg or 600 mg of CBD oil did not experience the same effects.
CBD oil might help people with substance use disorder, according to a 2015 review published in the journal Substance Abuse.
The review looked at the findings from 14 published studies. Nine of the studies looked at the effects of CBD on animals, and five studies looked at the effects on humans.
The researchers reported that CBD showed promise for treating people with opioid, cocaine, or psychostimulant use disorders.
However, the effects of CBD were quite different depending on the substance. For example, CBD without THC did not decrease withdrawal symptoms related to opioid use.
On the other hand, it did reduce drug-seeking behaviors in people using cocaine, methamphetamine, and other similar drugs.
Some experts suggest that CBD could help treat cannabis and nicotine dependence, but more research is needed to provide this theory.
High Blood Pressure
A 2017 study found that CBD oil may reduce the risk of heart disease because it can lower high blood pressure in some people.
For the study, nine healthy men took either 600 mg of CBD or the same dose of a placebo. The men who took CBD had lower blood pressure before and after experiencing stressors like exercise or extreme cold.
The study also looked at the amount of blood remaining in the heart after a heartbeat (stroke volume).
The stroke volume in the men who took CBD was lower than in was in the placebo group, meaning their hearts were pumping more efficiently.
The study suggested that CBD oil could be a complementary therapy for people with high blood pressure that is affected by stress and anxiety.
However, there is no evidence that CBD oil can treat high blood pressure on its own or prevent it in people at risk. While stress can complicate high blood pressure, it does not cause it.
In June 2018, the U.S. Food and Drug Administration (FDA) approved a CBD oral solution called Epidiolex.
Epidiolex is used to treat two rare forms of epilepsy in children under the age of 2: Dravet syndrome and Lennox-Gastaut syndrome. These are very rare genetic disorders that cause lifelong seizures starting in the first year of life.
Other than for these two disorders, CBD’s effectiveness for treating seizures is not known. Even with Epidiolex, it’s not clear if the anti-seizure effects are from CBD or another factor.
However, there is some evidence that CBD interacts with seizure medicines like Onfi (clobazam) and raises their concentration in the blood. That said, more research is needed to understand the link.
Possible Side Effects
Clinical research has shown that CBD oil can cause side effects. The specific side effects a person has and how bad they are varies from one person to the next and from one type of CBD to another.
Some common side effects people report from using CBD include:
- Changes in appetite
- Changes in mood
- Dry mouth
CBD oil may also increase liver enzymes, which is a marker of liver inflammation.
People with liver disease should talk to their healthcare provider before taking CBD oil. They may need to have their liver enzymes checked regularly if they are using CBD.
Can You Use CBD If You’re Pregnant?
You should not use CBD oil if you’re pregnant or breastfeeding. Even though the effects of CBD are not fully understood, it does pass through the placenta.
The American Academy of Pediatrics (AAP) further states that pregnant people should not use marijuana because of the potential risks to a developing fetus.
Do not drive or use heavy machinery when taking CBD oil—especially when you first start using it or switch to a new brand. Remember that some products do contain THC, even in small amounts.
CBD oil can interact with medications, including many that are used to treat epilepsy. One of the reasons for this has to do with how your body breaks down (metabolizes) drugs.
Cytochrome P450 (CYP450) is an enzyme your body uses to break down some drugs. CBD oil can block CYP450. That means that taking CBD oil with these drugs could make them have a stronger effect than you need or make them not work at all.
Drugs that could potentially interact with CBD include:
- Anti-arrhythmia drugs like quinidine
- Anticonvulsants like Tegretol (carbamazepine) and Trileptal (oxcarbazepine)
- Antifungal drugs like Nizoral (ketoconazole) and Vfend (voriconazole)
- Antipsychotic drugs like Orap (pimozide)
- Atypical antidepressants like Remeron (mirtazapine)
- Benzodiazepine sedatives like Klonopin (clonazepam) and Halcion (triazolam)
- Immune-suppressive drugs like Sandimmune (cyclosporine)
- Macrolide antibiotics like clarithromycin and telithromycin
- Migraine medicine like Ergomar (ergotamine)
- Opioid painkillers like Duragesic (fentanyl) and alfentanil
- Rifampin-based drugs used to treat tuberculosis
Always tell your healthcare provider and pharmacist about all the medicines you take, including prescription, over-the-counter (OTC), herbal, or recreational drugs.
The interactions between these medications and CBD are often mild and you might not have to change your treatment.
However, in some cases, you might have to change medications or space out your doses to avoid a reaction. That said, never change or stop medication without talking to your provider.
Dosage and Preparation
There are no guidelines for using CBD oil. Each product works a bit differently, depending on the form.
For example, putting the oil under your tongue can produce effects more quickly than swallowing a capsule that needs to be digested.
Here are a few ways that you can take CBD oil:
- Placing one or more drops under your tongue and holding it there for 30 to 60 seconds without swallowing. You can also use a spray that is spritz in your mouth/under your tongue.
- Taking a capsule or chewing a gummy
There’s no “correct” dose of CBD oil. How much you take and the form you choose will depend on your needs and what you hope to get for effects. The average dose range is from 5 mg to 25 mg.
Most oils come in 30-milliliter (mL) bottles and include a dropper cap to help you measure.
That said, it’s hard to figure out the exact amount of CBD per milliliter of oil. Some tinctures have concentrations of 1,500 mg per 30 mL, while others have 3,000 mg per mL or more.
How to Calculate CBD Dose
To determine an exact dose of CBD, remember that each drop of oil equals 0.05 mL of fluid. This means that a 30-mL bottle of CBD oil will have about 600 drops in it.
If the concentration of the tincture is 1,500 mg per mL, one drop would have 2.5 mg of CBD in it. The math to figure that out looks like this: 1,500 mg ÷ 600 drops = 2.5 mg
What to Look For
CBD oil comes in different forms: isolates, broad-spectrum, and full-spectrum.
- Isolates contain only CBD
- Broad-spectrum oils nearly all of the components of the plan (e.g., proteins, flavonoids, terpenes, and chlorophyll), but does not have THC oils have all the compounds including THC (up to 0.3%)
Alternative medicine practitioners believe that the compounds provide more health benefits, but the is a lack of evidence to support these claims.
Remember that CBD oils are unregulated. There’s no guarantee that a product is what it claims to be on its packaging. You also can’t know for sure that it’s safe and effective.
A 2017 study reported that only 31% of CBD products sold online were correctly labeled. Most had less CBD in them than was advertised, and 21% had significant amounts of THC.
If you are interested in buying CBD products, here are a few tips to keep in mind:
- Buy American: Domestically produced CBD oil might be a safer option than those that have been imported.
- Go organic: Brands certified organic by the U.S. Department of Agriculture (USDA) are less likely to expose you to pesticides and other harmful chemicals.
- Read the product label: Even if you choose a full-spectrum oil, don’t assume that every ingredient on the product label is natural. CBD products can also have preservatives, flavorings, or thinning agents in them. If you don’t recognize an ingredient, ask the dispenser what it is or check online.
Hemp plants can be grown for different purposes. Some species are made for marijuana but others are used to make CBD products.
Unlike marijuana, CBD oil does not “get you high.” Instead, it may help relieve stress, anxiety, drug withdrawals, and nerve pain.
While there are many claims about the health benefits of using CBD oil, the evidence is lacking. A lot of studies were done with animals, not humans.
If you want to try CBD oil, you should learn about the different dosages and preparations first.
You should also know that the products are not regulated, which means you can’t know for sure that a product will work and be safe.
Before you use CBD oil, talk to your provider. If you take certain medications or have a health condition, you may not be able to use these products.
Frequently Asked Questions
It would be hard to overdose on CBD oil. Research has shown that human tolerance for CBD is very high. One study reported the toxic dose would be about 20,000 mg taken at one time.
It depends on where you live, the type of product, how it was sourced (e.g., is it from hemp or marijuana), and its intended purpose (medical or recreational). In many states, you must be 18 or 21 to buy CBD oil. Check your state’s laws.
Not necessarily. While the names are sometimes used interchangeably, hemp oil can also refer to hemp seed oil, which is used for cooking, food production, and skincare products.
CBD oil is made from the leaves, stems, buds, and flowers of the Cannabis indica or Cannabis sativa plant. It should contain less than 0.3% THC.
Hemp oil is made from the seeds of Cannabis sativa and does not have TCH in it.
CBD Dosage: How Much Should You Take?
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Table of Contents
- Determining the Best CBD Dosage for You
- How to Calculate CBD Dosage
- How to Take CBD
Cannabidiol (CBD) is growing increasingly popular, thanks to its many purported health benefits and non-intoxicating properties (most CBD products contain less than 0.3% tetrahydrocannabinol, or THC). In fact, 60% of U.S. adults have tried CBD at some point and believe it has medicinal benefits, according to a recent Forbes Health survey of 2,000 U.S. adults conducted by OnePoll. As research evolves and sheds light on CBD’s efficacy, especially for pain relief, more and more people are adding it to their daily wellness regimens.
Consumers can choose from a variety of CBD products, from oils to gummies to vapes to capsules. But figuring out the safe and effective CBD dose for an individual is a complex decision.
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Here’s how to find the right CBD dosage for you and how to consume it safely.
Determining the Best CBD Dosage for You
With the exception of one CBD product, a prescription drug used to treat seizures associated with particular syndromes, the Food and Drug Administration (FDA) doesn’t regulate the use of CBD. (In fact, it’s illegal to market CBD as a supplement or add it to food.) Therefore, it’s best to consult a doctor with experience in CBD administration to determine your ideal dosage.
Expressed in milligrams (mg), CBD dosage largely depends on the conditions and symptoms you’re trying to treat and your unique endocannabinoid system, which is associated with motor control, behavior, emotions, the nervous system and homeostasis. CBD dosage remains an area of active research—more large, high-quality studies are needed in different populations to determine appropriate dosing, efficacy and safety guidelines.
“It’s best to start small and gradually increase your dose up to a level that gives you the desired effect,” says Cheryl Bugailiskis, M.D., a cannabis specialist at Heally, a telehealth platform for alternative medicine. Your starting point might look like half a CBD gummy or a drop of oil. Ideally, navigate this process under the guidance of a qualified physician.
If you’re still not sure where to start, mydosage.com offers a questionnaire and CBD calculator to help you based on your specific symptoms and usage goals.
How to Calculate CBD Dosage
When you consume CBD gummies, capsules or softgels, dosage is typically expressed per unit. For example, there may be 50 milligrams of CBD in each individual gummy. These products don’t offer much dosage flexibility since you can’t split up capsules easily. For instance, if one softgel capsule didn’t provide your desired result, you would have to take another full capsule, doubling the total dose.
CBD oil, on the other hand, makes it easier, to begin with a small dose. But calculating CBD oil dosage can be less straightforward. Oils and tinctures tend to come in a dropper bottle and, typically, only the total liquid volume and CBD contents are listed on the label. For example, the label might simply state there’s 1,500 milligrams of CBD in the 30-milliliter bottle.
But what does 1 milliliter look like? Due to the current lack of regulation of CBD, this calculation can be tricky. Start by figuring out the volume of a single drop in your dropper, which is usually 0.05 milliliters, according to Dr. Bugailiskis. If you’re unsure, ask the company.
Here’s where math comes in. Let’s continue with the 30-milliliter bottle with 1,500 milligrams of CBD and 0.05 milliliters in a single drop as our example.
1500mg÷30mL = 50 mg/mL
This bottle contains 50 milligrams of CBD per milliliter. Let’s see how many milligrams are in a drop:
50mg/mL ×0.05mL/drop = 2.5mg/drop
Each drop contains 2.5 milligrams of CBD.
Next, you can calculate how many drops you need to reach your goal dosage. Let’s say you want to consume 25 milligrams each day.
25mg÷2.5mg/drop = 10 drops
10 drops ×2.5mg = 0.5mL
With this CBD oil dosage calculator as your guide, you would find that you needed to consume 10 drops, or 0.5 milliliters, to reach 25 milligrams. And if you intend to consume 25 milligrams daily, you can expect this particular bottle to serve as a 60-day supply.
Some CBD products do some of this math for you and illustrate how many milligrams are in a milliliter, some even marking these points on the dropper so you know exactly what you’re taking.
CBD Dosage for Different Ailments
Without FDA approval, there is little guidance in the U.S. on how much CBD a person should consume for various conditions.
In many medical studies on CBD, you see administered doses reach hundreds of milligrams a day, which sounds severe compared to our starting dosage example of 25 milligrams. However, Steven Phan, founder of Come Back Daily, a CBD dispensary in New York, points out that patients in these studies are often dealing with serious flare-ups and pain-inducing conditions compared to everyday dispensary customers.
Below are clinically-studied CBD dosages based on different ailments and conditions. Note: Some of the formulations studied contained THC as well—not all available dosage research sticks strictly to CBD.
*Dosages are based solely on small, short-term clinical study results where CBD proved significantly successful over placebo. Much larger studies are needed to further strengthen the evidence.
FDA-approved Epidiolex administers CBD orally as a liquid to treat seizures associated with Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex. The dosage of Epidiolex is determined by taking the patient’s weight in kilograms (kg) into account.
Several countries, including Canada and those in the U.K., have approved the use of Sativex, an oral spray with equal amounts of CBD and THC, to treat pain stemming from multiple sclerosis. Canada has also approved it for treatment of cancer pain.
The medical and research community still has a long way to go before figuring out what dose works best for each condition. At an individual level, consumers can experiment with caution until they find what works best for them.
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How to Take CBD
Popular ways to take CBD include:
- Oils and tinctures (extracts of plant material dissolved in ethanol): A liquid that comes in a bottle with a dropper
- Gummies: A soft, chewable candy that’s often fruit-flavored
- Sprays: A liquid that comes in a bottle with a nozzle for spraying into the mouth
- Capsules: Tablets or softgels that are ingested by mouth
- Vapes: CBD oil that’s heated without ignition, resulting in an inhalable vapor
- Flower: Dried hemp plant that’s often ignited and smoked
- Edibles: Any food that CBD oil has been added to, such as brownies or chips
- Drinks: Any beverage that’s infused with CBD, often in the form of hemp extract
Your CBD product of choice will largely depend on your personal preferences, as well as your budget since prices vary depending on the potency of ingredients and manufacturing processes. Different mediums also offer varying levels of bioavailability—or how much of what you take is actually absorbed into your bloodstream to have an effect. For example, if you ingest 10 milligrams of CBD via 1 milliliter of liquid, your body might absorb about 60% of it, or about 6 milligrams.
Cannabinoids generally have a low bioavailability compared to other substances, according to Jordan Tishler, M.D., a physician specializing in cannabis treatment in Massachusetts. However, “products that contain emulsifiers like egg yolk (brownies) or lecithin (some gummies) do better,” he says.
With that said, ingesting CBD via gummies or other edibles may take longer to take effect since the CBD has to travel to your digestive system to be broken down and absorbed.
Can You Take Too Much CBD?
Like with any substance, you can take more CBD than your body can handle. Studies show doses up to 1,500 milligrams a day have been well-tolerated, but every person is different  Bergamaschi MM, Costa Queiroz RH, Zuardi AW, Crippa JAS. Safety and side effects of cannabidiol, a Cannabis sativa constituent. Current Drug Safety. 2011;6(4):237-49. . Ingesting too much CBD can cause unpleasant side effects, such as dry mouth, nausea, diarrhea, upset stomach, drowsiness, lightheadedness and general disorientation. While rare, liver damage can also occur.
What’s more, CBD can have serious interactions with certain medications. In evaluating available information on five prescription CBD-based medications, researchers found 139 medications could have a potential drug-drug interaction with CBD  Kocis PT, Vrana KE. Delta-9-Tetrahydrocannabinol and Cannabidiol Drug-Drug Interactions. Medical Cannabis and Cannabinoids. 2020;3:61–73. . People who take certain blood thinners, heart rhythm medications, thyroid medications and seizure medications need to be particularly careful.
At the end of the day, not all supplements are created equal, which is why it’s important to work alongside a health care provider when adding CBD to your wellness regimen and research reliable brands. And while emerging research and anecdotal evidence is promising, more large, randomized-controlled trials are needed to further understand the benefits of CBD and its dosing.