CBD oil is an extract of the cannabis or hemp plant used by millions of people around the world as a natural remedy for a wide range of ailments, and to promote general wellbeing.
A major study of CBD users found it was most commonly used to treat pain, anxiety, depression and sleep disorders but was also taken by those aiming to combat the symptoms of migraines and headaches, PTSD, nausea, cancer, allergies, epilepsy, multiple sclerosis, Parkinson’s disease and Alzheimer’s. Over 65% of those who took part in the study said that CBD oil treated their conditions ‘very well’ or ‘moderately well’ without the use of other remedies or medications.
Scientific evidence for the effectiveness of CBD varies depending on symptoms. In some instances, such as anxiety, stress, sleeping disorders and pain, pre-clinical studies appear to provide initial support for its use. When it comes to certain forms of epilepsy and multiple sclerosis, there are already specialist medicines available by prescription. In the case of other ailments, some animal and laboratory studies have been encouraging.
Scientists researching CBD’s potential as a therapeutic treatment tend to agree both that further study is warranted and that CBD oil has a relatively low level of serious side-effects, making it a good candidate for such studies (see CBD oil side-effects).
Scroll down for a more in-depth look at the potential benefits of CBD oil for each condition.
CBD, or cannabidiol, is the second most common compound of the cannabis plant, after THC. But unlike THC, CBD does not get you high.
Perhaps the most popular way to buy CBD is as the active ingredient in a bottled oil. Measured doses can be dropped directly into the mouth or added to food and drink (see How to take CBD oil).
CBD oil is also available in capsules, soft gels, chewable ‘gummies’, topical creams and in e-juices used for vaping.
In the UK, CBD products are not currently allowed to make medical claims (so it’s best to avoid any that do) and are instead classified as a food supplement. However, the Food Standards Agency generally considers CBD oil to be safe for non-vulnerable people (see Is CBD oil safe?).
More information on CBD oil can be found here.
How does CBD oil work?
The Endocannabinoid System
CBD is a cannabinoid and originates in cannabis plants rather than within the body. However, many of its potentially beneficial effects may be related to its interaction with an internal system called the Endocannabinoid System (ECS).
Put simply, the ECS consists of two different receptors, known as CB1 and CB2, and two substances known as endocannabinoids – anandamide (AEA) and 2-arachidonoylglyerol (2-AG) – which are produced by the body as required and bind to the receptors, sending signals around the nervous system.
The overall purpose of the ECS appears to be homeostasis – the maintenance of a stable internal state across functions including appetite and metabolism, pain, inflammation and the immune system, mood, stress and sleep, and organ functions, all of which relate to claims made about the benefits of CBD.
Some researchers believe that CBD may prolong the effects of endocannabinoids by slowing their breakdown. Others suggest that it may interact with an as-yet-unknown third ECS receptor.
CBD also effects the levels of a number of other neurotransmitters and hormones in the body, including serotonin (produced from the precursor 5-HTP) which is known to help stabilise mood and promote a sense of wellbeing.
CBD oil for pain
A 2019 Gallup poll found that pain is the symptom CBD oil is most commonly used to treat among Americans, with arthritis-specific pain the fourth most common. In another survey of over 2,400 CBD oil users in the US, those who used it for chronic pain, or arthritis and joint pain, were the respondents who most frequently felt that CBD treated their condition “very well by itself” or “moderately well by itself”.
Beneficial effects of CBD oil on pain may in part be due to its interaction with the Endocannabinoid System (see How does CBD oil work?) which regulates a number of responses in the body including those of the immune system, such as inflammation.
Several studies appear to provide early support for the pain-relieving potential of cannabinoids such as CBD.
A review of 18 trials on cancer patients found that a combination of CBD and THC “demonstrated a significant analgesic [pain-killing] effect of cannabinoids”.
One study on rats found that CBD reduced the negative experience of pain related to incisions, while another focusing on the effect of CBD on sciatic nerve pain and inflammation concluded that “the results indicate a potential for therapeutic use of cannabidiol in chronic painful states”.
CBD oil for arthritis
Within the wider area of pain and inflammation, a great deal of interest has been shown in the potential benefits of CBD oil in treating pain symptoms caused specifically by arthritis.
A recent survey by the Arthritis Foundation of more than 2,600 arthritis patients found that 79% were either currently using CBD, had used it in the past or were considering using it. Among those using CBD, 94% said the primary reason was to relieve pain and 3 out of 4 reported that it was either “effective” or “very effective” in relieving their symptoms.
A trial on rats with arthritis concluded that treatment with a CBD gel demonstrated “therapeutic potential for relief of arthritis pain‐related behaviours and inflammation without evident side‐effects”, while a study of human osteoarthritis patients was inconclusive but appeared to indicate a more beneficial effect on men than women.
The Arthritis Foundation says that those interested in trying CBD should first consult the heath care professional responsible for treating their arthritis.
Anxiety is the second most common condition prompting people to turn to CBD oil as a remedy. That’s according to both a 2019 Gallup poll and a 2018 survey of CBD users in the US. And there is some compelling initial evidence from human studies to support its potential effectiveness.
A retrospective review of 72 psychiatric patients given CBD to treat anxiety and sleep disorders, found that anxiety symptoms decreased in almost 80% in the first month of usage. Meanwhile, two studies examining subjects’ levels of anxiety in relation to a simulated public speaking test showed that CBD had anxiety-supressing properties in stressful situations.
More information on CBD Oil for anxiety can be found here.
CBD oil for depression
It’s less clear how common a treatment CBD oil is in those suffering from depression in comparison with anxiety. However, the relative tolerability of CBD compared with the unpleasant side-effects of some traditional anti-depressants, make it an attractive alternative for some.
Research on the effectiveness of CBD oil in treating symptoms of depression is currently limited but one regularly cited test on mice concluded that CBD induced anti-depressant-like effects comparable to those of the clinical anti-depressant imipramine (sold under the brand name Tofranil). The study suggests that the effects were likely the result of CBD’s interaction with the body’s 5-HT receptors, which produce serotonin, the key hormone responsible for stabilising mood and engendering a feeling of wellbeing.
CBD oil for sleep
A review of studies on the effects of cannabinoids on sleep disorders concluded that CBD may have potential for treating insomnia, REM (dream) sleep disorders and excessive daytime sleepiness.
In many cases, the effectiveness of CBD in helping insomnia may depend on the causes. As explored above, there is good initial evidence that CBD has a beneficial effect on pain and anxiety, both of which can be root causes of sleeping difficulties.
A recent study of psychiatric patients given CBD to treat sleep disorders and anxiety found that almost 80% saw a reduction in anxiety while 67% subsequently reported improved sleep.
Certainly, many users cite problems sleeping as their main reason for taking CBD oil. Eleven per cent of those who took part in a 2019 poll said they used CBD oil for sleep-related problems, making it the third most common use after pain and anxiety.
CBD oil for cancer
Although claims around cancer should be treated with caution, there is evidence that CBD could help to relieve some cancer-related symptoms. Early laboratory results even suggest that in some situations CBD can cause the death of cancer cells, block their growth and reduce their ability to spread.
A 2009 study of cancer patients whose pain could not be relieved by opioids found that a combination of CBD and THC was more effective than a placebo, or than either of the cannabinoids alone, while another the following year showed that the same combination helped with nausea and vomiting resulting from long-term chemotherapy treatment.
Test tube trials on the effect of CBD on breast cancer cells recommended continued research into the potential of CBD as an anti-tumour agent, while a mouse study saw CBD decrease the effect of a protein that influences tumour growth in human breast cancer cells. However, it’s important to note that these results may not be replicated in human subjects and only highlight the need for further study.
CBD oil for epilepsy and seizures
Epilepsy is one of only two illnesses for which there are approved CBD-based medicines available by prescription on the NHS. Epidiolex – also approved by the US Food and Drug Administration (FDA) – is made from 98% pure CBD and is used to help reduce the seizures associated with epilepsy in those suffering from Dravet Syndrome and Lennox-Gastaut Syndrome, two rare and often hard to treat forms which begin in childhood.
One 12-week trial of CBD involving epilepsy patients with treatment-resistant forms of the disease reported a 36.5% median average reduction in seizures. Despite many patients reporting side-effects including drowsiness, decreased appetite, diarrhoea and fatigue, only 3% chose to drop out of the study because of them, leading the researchers to conclude that CBD might be suitable as a treatment for children and young adults.
According to UK charity Epilepsy Action, a recent review found that 1 in 8 people with hard to treat forms of epilepsy experienced a 50% or greater reduction in seizures after taking CBD, and some became entirely free of seizures.
CBD oil for multiple sclerosis
Multiple sclerosis is a condition that effects nerve cells in the brain and spinal column, leading to symptoms including visual problems, muscle weakness and difficulties with co-ordination. Along with epilepsy, it is the other illness for which an approved medicine containing CBD is available.
Nabiximols, brand name Sativex, is a combination of CBD and THC, the psychoactive compound in cannabis. It is used to treat spasticity – a tightening and stiffening of the muscles that can affect movement and speech in those with multiple sclerosis.
A non-clinical study of those using Nabiximols in Germany showed it significantly reduced spasticity in almost 75% of patients after one month of use.
CBD oil for Alzheimer’s disease
Alzheimer’s disease is a degenerative illness that effects brain functions and is one of the major causes of dementia. Interest in CBD as a treatment for Alzheimer’s stems from encouraging results in initial animal and laboratory studies.
The complexity of symptoms in Alzheimer’s disease means that an approach targeting the various problems with a combination of drugs may be the most effective way forward. One common symptom in Alzheimer’s sufferers is the increasing inability to recognise people, including those close to them.
One study showed that CBD can prevent so-called ‘social recognition deficit’ in mice with Alzheimer’s, leading the researchers to conclude that it may have the potential to tackle the same problem in humans.
A review of test tube studies into the possible beneficial effects of CBD on Alzheimer’s concluded that there was “promising preliminary data”.
CBD oil for Parkinson’s disease
Like Alzheimer’s, Parkinson’s disease is a neurodegenerative condition but as well as damaging the brain and eventually resulting in dementia it also effects the wider central nervous system, leading to problems with movement, including tremors.
The results of research into the potential beneficial effects of CBD on Parkinson’s have varied depending on the symptoms being evaluated. One study suggested no measurable effect on motor problems and general symptoms but a significant improvement in overall quality of life, while another showed CBD was able to control the symptoms of a sleep behaviour disorder during which patients experienced nightmares and were physically active while dreaming.
CBD oil for migraines and headaches
The idea that CBD oil could help treat headache, and specifically migraine, symptoms comes in large part from its apparent beneficial effects on pain and inflammation and its possible ability to reduce nausea, one of the symptoms sometimes associated with migraines.
A 2018 review of studies by the scientific journal Headache concluded that there was an increasing amount of evidence that CBD and THC may be effective in the treatment of pain, and that this might include the symptoms of migraines and headaches.
CBD oil for blood pressure and heart health
We’ve already seen that the use of CBD helped tackle increased blood pressure in a study related to stress (see CBD oil for anxiety) but the same study also showed that CBD reduced resting blood pressure, suggesting that after further research it could play a part in the treatment of cardiovascular disorders. As in the case of other conditions, CBD’s apparent anti-inflammatory properties could be part of the answer here.
“Inflammation is part of the process that leads to many diseases, including coronary heart disease, high blood pressure and stroke and there is some evidence that CBD has anti-inflammatory properties,” says the British Heart Foundation.
Meanwhile, a study of mice treated with CBD for diabetic heart disease reported ‘remarkable’ reduction in a number of the symptoms, and concluded that it may have the potential to treat cardiovascular problems in humans.
CBD oil for diabetes
Diabetes is an illness in which sufferers experience prolonged high blood sugar levels, resulting either from a failure to produce sufficient insulin (Type-1 diabetes) or an inability to respond to the insulin they do produce (Type-2 diabetes).
Left untreated, diabetes can lead to serious symptoms including heart disease, kidney diseases, stroke, foot ulcers and damage to the nerves and eyes, and can be fatal.
In the section on CBD for heart health above we noted that CBD may have potential in treating some complications of diabetes including heart disease, thanks in part to its anti-inflammatory properties.
There is further initial evidence that CBD could help reduce one of the root causes of diabetes, the inflammatory condition insulitis. A study of non-obese diabetic mice showed that CBD ‘inhibited and delayed’ insulitis, leading to a drastic reduction in instances of diabetes, from 86% in a control group to 30% in those treated with CBD.
As always, it’s important to remember that the results of animal studies may not be replicable in humans and can only suggest directions for further study.
CBD oil for schizophrenia and as an anti-psychotic
Psychosis is a mental health condition in which sufferers have difficulty distinguishing between reality and their own thoughts and ideas. Schizophrenia is a chronic condition featuring repeated bouts of psychosis. Symptoms may include visual or auditory hallucinations – such as hearing voices – delusions, and social and emotional problems. Crucially, current drug treatments are limited in the symptoms they treat and may often cause unpleasant side-effects.
A number of studies have considered the potential benefits of CBD oil on schizophrenia, with promising results. A recent review of the research into CBD and psychosis found that in many “CBD seemed effective as a treatment for psychosis” and “may have the capacity to alleviate positive, negative, and cognitive symptoms in schizophrenia”.
It also concluded that CBD was significantly more likely to be effective as a treatment if used in the early stages of such psychotic disorders.
CBD oil for addiction
CBD interacts with a number of naturally occurring substances in the brain that influence addiction, including endocannabinoids (see How does CBD oil work?), serotonin and Gamma aminobutyric acid (GABA), and there is some evidence that it may be able to help those with a dependency on certain drugs.
An assessment of 14 studies into CBD and addiction noted that animal research had highlighted possible therapeutic effects on those addicted to the pain-relieving drugs opioids, as well as stimulants such as cocaine and amphetamines, while human studies provided some initial evidence of beneficial effects on cannabis and tobacco dependency.
However, the review also pointed out that data were currently limited and far from conclusive, recommending controlled trials as a next step.
A more recent review, examining CBD’s potential as a treatment for psychosis and addiction, concluded that it showed particular promise in the case of cannabis dependency, leading to a reduction in craving and withdrawal in almost all studies, as well as instances of reduced anxiety and depression.
CBD oil for fibromyalgia
There are a number of symptoms associated with fibromyalgia but the most significant are chronic, widespread pain and an increased sensitivity to pressure on the surface of the body. Since there is good evidence that CBD can help to relieve pain (see CBD oil for pain), it’s no surprise that there is interest in what it might do for fibromyalgia.
However, research specifically involving CBD and fibromyalgia patients is scarce and where it does exist has tended to look at whole cannabis as a treatment for fibromyalgia, rather than CBD in its isolated form.
A study of three strains of inhaled pharmaceutical grade cannabis showed an increase in respondents reporting a 30% pain reduction following electrical pain stimulus, as well as a significant increase in their pressure pain thresholds – but only in varieties of cannabis containing the psychoactive compound THC as well as CBD.
CBD oil for acne
Acne vulgaris is the most common skin complaint in the world and one that most people will experience at some point in their lives. A major contributing factor is the over-production of sebum, a protective oily substance secreted by follicles in the skin. Too much sebum can lead to clogged pores which can then become inflamed.
A test tube study using human skin cultures and sebum-producing skin cells showed that CBD reduced both the production of sebum cells and inflammation, concluding that CBD shows potential as a treatment for acne.
CBD oil side-effects
Interest in CBD as both a natural remedy and a subject for scientific research is in part due to the fact that it is considered to have few serious side-effects. In clinical terms, CBD is generally ‘well tolerated’, meaning it is relatively rare for subjects to choose to opt out of studies involving CBD as a result of negative side-effects.
Nevertheless, there are some usually low-level side-effects regularly associated with CBD oil that are worth being aware of. Dry mouth is the most common, noticed by 11% of those who took part in a 2018 study of over 2,400 CBD users, with increased hunger (6%), red eyes (less than 3%) and drowsiness (less than 2%) also reported. Other sources suggest CBD oil can sometimes cause nausea and diarrhoea.
Is CBD oil safe?
A report by the World Health Organization on CBD found no evidence of addiction or public health problems related to CBD and it’s important to remember that it does not have the psychoactive effects associated with THC, the active ingredient in marijuana, so will not get you high.
As precautionary measures, the UK’s Food Standards Agency advises that vulnerable people, such as pregnant and breastfeeding women and those taking medication, do not use CBD and that healthy adults take no more than 70mg a day.
In general, it is sensible to talk to your doctor if you are considering taking CBD oil.
How to take CBD oil – products and methods
CBD most commonly comes as a bottled oil, usually with an integrated pipette which allows you to drop a measured dose directly into your mouth. The safest and most efficient way to take CBD oil is sublingually, that is directly under the tongue where the high density of blood vessels at the surface allow for maximum absorption. Just hold it there for a few moments before swallowing.
CBD oil can also be swallowed directly, added to drinks such as coffee and smoothies, or mixed into food just before eating. However, there is evidence that the process of digestion may prevent full absorption and also that CBD in a solution can start to break down at heats above 71°F. It’s also worth considering research suggesting that ingested CBD is better absorbed when accompanied by food or drink with a higher fat content.
Edible CBD also comes in soft gels, capsules or chewable gummies, which many people find a more pleasant or convenient way of consuming it. Of course, the same issues around digestion apply here, meaning varying amounts of CBD may be lost in transit.
Vaping e-juices containing CBD is another popular way of consuming it and can provide fast and direct assimilation, although it’s still unknown how safe vaping itself is.
Topical creams are another potential delivery mechanism for CBD, via cannabinoid receptors (see How does CBD oil work?) in the skin and there is some evidence that CBD creams may help with localised complaints such as arthritis.
How long does CBD oil take to work?
The speed with which CBD enters your bloodstream – and therefore has the potential to begin delivering beneficial results – can vary hugely depending on how you take it. Vaping CBD and thereby inhaling it directly into the lungs, is the fastest (if not necessarily the safest) method and should take just a matter of minutes.
Taking drops of CBD oil sublingually – ie, holding it under the tongue before swallowing – exposes it to a high concentration of surface blood vessels so is also a rapid way of assimilating the CBD.
Ingesting CBD – ie swallowing it as droplets or adding it to food or drink – will take longer to have an effect, more likely measured in hours than minutes and also dependent on what else you’ve eaten and how recently.
There are a whole range of intertwined aspects of an individual’s chemical make-up that are also likely to influence the speed of uptake of CBD oil.
CBD oil dosage
The ideal dosage of CBD oil can vary based on factors including age, weight and specific body chemistry, the condition you’re aiming to treat and how you take the oil, which will influence how much of the active ingredient reaches your bloodstream and how quickly (see How to take CBD oil).
A sensible approach is to start with a small dose, say 5-10mg per day, and gradually add more until you achieve the effect you’re looking for without any unwanted side-effects (in which case, reduce the dosage). Take each dosage for a few days before increasing it, in order to allow your body time to respond, and make a note of how you feel afterwards so you can look back and assess the optimum dosage.
You might also like to experiment with smaller doses taken several times a day, rather than larger one-off amounts. Try a little at a time to see what works best for you.
Jersey Hemp’s CBD dosage calculator will give you a general idea of the amount you might end up taking.
What’s the best CBD oil?
According to a recent report by the Centre for Medical Cannabis, the quality of CBD products in the UK can vary wildly. While the best products were deemed “very high quality and… good options for today’s consumers”, many were found to contain far less CBD than claimed on their labels or to contain illegal amounts of THC, the psychoactive ingredient in cannabis.
Eleven of the 29 products tested had less than 50% of the advertised CBD content and one high street pharmacy product contained no CBD at all. Almost half of the products had detectable levels of THC. While this averaged only 0.04%, compared to the allowable level of 0.01%, and would not lead to users experiencing the high associated with marijuana, it does make the products technically illegal in the UK and reflects poorly on the brands’ refinement and testing processes.
Many CBD brands sold in the UK use imported hemp where a low cost-price is more important than quality and traceability. It’s therefore important to choose a trustworthy brand with the highest processing standards that can demonstrate the provenance of its ingredients.
Jersey Hemp was granted the first licence for the harvesting of hemp for CBD production in the British Isles and all the hemp it uses in its products comes from its own fields. Every batch of CBD oil undergoes rigorous quality control by its team of scientists, researchers and agricultural experts and is tested by an independent laboratory, with results available to view on the website, making it one of the most trustworthy CBD brands in the UK.
The Centre for Medical Cannabis called Jersey Hemp “one of the most compliant, high quality and accurately labelled products that we tested.”
Jersey Hemp CBD oils come in 5% and 10% concentrations and in full-spectrum versions.