Updated: Nov 22, 2019
You may have noticed CBD oil for sale in health food shops and wondered is it really as therapeutic as the claims around it. Or you may have read conflicting reports or newspaper articles.
This article takes a look at the current research and some important information concerning CBD oil, if you are considering using it.
Hemp (Cannabis sativa L.) is one of the oldest and most sustainable crops to be grown worldwide due to its’ nutritional value and versatility. Traditionally it has been grown for rope, fishing nets and textiles. Hemp seeds are made into a nutrient-dense oil, and also made into a protein powder after the oil has been removed.
CBD stands for cannabidiol, which is one of the cannabinoids found in the cannabis plant. There are over 100 of these cannabinoids. It is legal to buy or sell in the U.K. as a food supplement, so long as the THC or tetrahydrocannbinol (another cannabinoid) levels are below 0.2%. THC is the compound found in cannabis responsible for its’ psychoactive effects.
It is easy to be confused by the different names given to cannabis. Cannabis is the name of the plant species, while marijuana and hemp are derived from different parts of the plant.
Marijuana is obtained from the female cannabis plants, with the highest levels of THC found in the flowers. While hemp is derived from the male and female plants but not the flowers.
Marijuana is illegal due to its’ THC content, the part of the plant which is psychoactive and responsible for the ‘high’ that cannabis is widely known for.
CBD has no psychoactive effects however it is thought to support health in several ways.
Is CBD oil legal?
Yes, CBD products that contain less than 0.2% THC, are legal to buy without a prescription in the U.K. They are used as a food supplement with beneficial nutritional and physical effects, supportive for many areas of health.
What is the difference between CBD oil and medical marijuana?
Medical licensed cannabis products and food supplement CBD oils are very different products, and should not be confused. Medical marijuana is derived from varying levels of THC and CBD, as well other cannabinoids and phytonutrients, including terpenes. Terpenes are the nutrients responsible for the colour, smell, and taste of CBD, which can be an acquired taste, but they do also have therapeutic potential of their own (1).
While CBD oil, which is sold as a food supplement, containing less than 0.2% THC, is non-intoxicating but still rich in cannabinoids and phytonutrients.
Is CBD oil the same as hemp oil?
It is important to note that CBD oil is not the same as hemp seed oil. Hemp seed oil is made by pressing the seeds, which produces a nutritious oil high in omega-3 and omega-6 oils, excellent in salad dressings, but not to be heated to high temperatures. Hemp seeds contain only very insignificant amounts CBD; therefore they do not have the same therapeutic health benefits.
Does CBD oil get you high?
Raw CBD does not get you high, as the THC is only in very negligible quantities (i.e. < 0.02%). CBD on its’ own is not psychoactive but may have other health-promoting effects.
What the research says
Appetite, mood, memory, pain and inflammation are the physiological processes in the body that are modulated by plant cannabinoids such as CBD and THC.
Naturally occurring cannabinoid receptors, known as CB1 and CB2, are found throughout the body including in the central nervous system and the immune system. CBD interacts with these receptors, regulating many bodily functions and helping to maintain balance.
Studies have shown that CBD may exert therapeutic potential for a wide range of health conditions such as Alzheimer’s disease (2), anxiety disorders including schizophrenia (3) and post-traumatic stress disorder (4), epilepsy (5), and several types of cancer (6). Some studies have shown that CBD blocks cancer cells from metastasis, suppressing their growth, and promoting cancer death (7).
There has also been some preliminary research into the benefits of CBD on insomnia and other sleep-related disorders, however, this research is still in its’ infancy and further studies are needed to help us understand its’ full therapeutic potential (8).
Dosage and strength
There are a wide range of CBD potencies generally ranging from 250mg to 1,000mg. Many products will be labeled as percentages, but knowing the amount in milligrammes enables more accurate dosing. For example, 500mg strength in a 10ml bottle is the same as 5% CBD.
Sourcing a good quality product is essential if you are considering trying CBD oil.
Look for a product that is raw, organic, and undiluted in other carrier oils for maximum therapeutic potential, preferably with a minimum of 500mg CBD per bottle.
Keep in mind that dosage is extremely individualised, as it can have differing effects with different people, depending on their age and current condition or symptoms. Always start low and go slow.
You can slowly build up from 1 or 2 drops per day of 500mg CBD oil (in total 5 to 10mg) up to 10 drops of 500mg CBD oil (in total 50mg). In extreme cases, up to 40 drops of 500mg CBD (in total 200mg) can be tolerated although it may not exert any more benefit than taking 10 drops. Increasing the dose by 1 drop per day is a good way to find your therapeutic level.
Many brands of CBD oil are extracted using olive oil, hemp oil or coconut oil as a carrier oil. This type of processing means that the CBD has been heated to 100˚C so it is therefore not a raw product, and because it is diluted, it has a lower potency (9).
Does CBD have side effects?
While the research is showing an array of beneficial health effects from taking CBD oil, it seems that there may also be some potential side effects, which may include low blood pressure, inhibited metabolism of hepatic (liver) drugs (see below), drowsiness and diarrhea.
These effects are quite uncommon and only occur in extreme cases, or when taking large quantities. Be sure to reduce your dosage if you experience any of these symptoms.
Potential drug interactions with CBD (contraindications)
Raw CBD oil has an excellent safety profile, however, in large doses, the oil does have the potential to inhibit the cytochrome P450 enzyme system.
The CYP450 enzyme system is found within the liver and it is responsible for metabolising and eliminating toxins from the body. Therefore, at high doses, CBD has the potential to reduce the effects of some pharmaceutical medications such as statins, blood thinners, painkillers, and insulin (10).
At low doses, it does not affect CYP activity, and potentially has many health-promoting effects. One clinical study showed no interactions when CBD was taken at a dosage of 40 to 50mg (9). This is the equivalence of taking 8 -10 drops of 500mg CBD oil.
If you are taking prescription medication, it is important to consult with your GP before taking CBD oil. It is not advised to take CBD oil if you are pregnant or breastfeeding.
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2. Cheng et al (2014) Long-term cannabidiol treatment prevents the development of social recognition memory deficits in Alzheimer’s disease transgenic mice. 42:1383-1396
3. Zuardi et al (2012) A critical review of the antipsychotic effects of cannabidiol: 30 years of a translational investigation. Curr Pharm Des 18:5131-5140
4. Blessing et al (2015) Cannabidiol as a potential treatment for anxiety disorders. Neurotherapeutics 12:825-836
5. Tzadok et al. (2016) ‘CBD-enriched medical cannabis for intractable pediatric epilepsy: The current Israeli experience’, Seizure. Doi: 10.1016/j.seizure.2016.01.004.
6. Guindon and Hohmann, 2011. The endocannabinoid system and cancer: therapeutic implicationBritish Journal of Pharmacology. doi: 10.1111/j.1476-5381.2011.01327.x.
7. Massi et al (2013) Cannabidiol as a potential anticancer drug. Br J Clin Pharm 75:303-312
8. Babson et al, 2017. Cannabis, Cannabinoids, and Sleep: a review of the literature. Current Psychiatry Reports. doi: 10.1007/s11920-017-0775-9.
9. Phillips, Elizabeth, 2018. ‘How to source and dose the best quality CBD oil’ https://blog.nutrigold.co.uk/2018/09/07/how-to-source-and-dose-the-best-quality-cbd-oil/
10. Yamaori (2011) Cannabidiol, a major phytocannabinoid, as a potent atypical inhibitor for CYP2D6. Drug Metab Dispos 39:2049-2056Stott et al (2013). A phase I, open-label, randomized, crossover study in three parallel groups to evaluate the effect of Rifampicin, Ketoconazole, and Omeprazole on the phamacokinetics of THC/CBD oromucosal spray in healthy volunteers. SpringerPlus 2:236