Getting Grounded In The CBD Basics

Cannabis and The Endocannabinoid System

CBD stands for Cannabidiol – a naturally occurring compound found in the resinous flower of the cannabis plant. Hemp oil is nothing new, and as you peruse the isles of Boots it’s increasingly common to see many beauty and wellness products bearing the cannabis leaf. However it should be noted that Hemp (Seed) Oil comes from the seeds, and whilst hosting a nutritiously dense profile, it does not contain active cannabinoids like CBD. These mostly come from the leaves and flowers (buds), but misleading labelling can make it confusing to distinguish Hemp Seed Oil from Hemp Oil / Extract / Distillate.

There are many other types of phytocannabinoids (plant-derived cannabinoids) in the Cannabis plant, including CBDA, CBG, THC and more. Each is believed to have its own specific benefit. The Cannabis plant comprises of two main species – Hemp and Marijuana. The difference between the two is the profile of cannabinoids, predominantly the ratio of CBD to THC. Tetrahydrocannabinol (THC) is the compound that gives Cannabis its reputation. This is the psychoactive molecule that gets you high, none of the other cannabinoids including CBD, have this effect. Therefore taking CBD will not get you high, unless it is mixed with THC.

At the moment it is not legal to grow or sell Marijuana in the UK. It is currently legal to grow Hemp in the UK with a licence from the Home Office, however it is still not legal to harvest the buds and leaves of the Hemp plant, meaning CBD can not be extracted from these areas on British soil. However the refined product can be imported from abroad, so long as the level of THC is <0.3%. 



Phytocannabinoids interact with our Endocannabinoid System (ECS). This is an extensive part of human physiology – with receptors in almost every organ of the body including the lungs, heart and brain. This signalling system is comprised of CB1 and CB2 receptors, with CB1 found mostly in the central nervous system (CNS) and CB2 primarily in the peripheral nervous system (PNS). As these receptors are linked to almost every system of the body, the ECS is involved in a huge plethora of functions – including homeostasis, sleep, mood, pain, appetite, fertility, and memory.

Whether or not you are a Cannabis user, you have an ECS that regulates your overall health and wellbeing, and your body produces its own natural cannabinoids as part of this. The body’s own supply of cannabinoids are known as endogenous cannabinoids, and those that are derived from external things such as the cannabis plant, are known as exogenous cannabinoids. The two are structurally similar, which means that exogenous cannabinoids interact with the body’s receptors in much the same way as endogenous ones.

The body’s supply of endocannabinoids can become disrupted via things like pollution and toxins, stress, hormonal imbalances and other common afflictions of modern living. This is why many people are turning to exogenous cannabinoids from mother nature to aid in restoring some of the balance. The market is teeming with options, however choosing the right product is not simple – it requires investigating purpose, formulation, bioavailabilitydose and some self-experimentationThere are also other lifestyle factors that affect your base level of cannabinoids, including coffee and exercise. 

There are more cannabinoid receptors in the brain than there are for ALL the neurotransmitters put together.’ The significance of cannabinoids for the body is undeniably important – and the ECS has the potential to have a powerful impact on the body. It’s a significant part of the makeup of every human being, and can have a substantial impact on our health.“ – Dr Ethan Russo

Is CBD Safe?

Quality, Quantity and Overdosing

Hemp has safely been used for thousands of years, and carries a fascinatingly rich cultural and spiritual history as a medicinal plant. It is believed that Cannabis had profound ritual and ceremonial use throughout ancient history. Today, modern science is beginning to test and uncover some of the mysterious mechanisms of these therapeutic phytocannabinoids, and we come full circle as we begin to re-investigate some of the wonders of this plant ourselves.

After much campaigning, the first CBD prescription to be approved by the FDA and made available for medical use was Epidiolex in 2018. It’s used to treat seizures caused by two forms of epilepsy: Lennox-Gastaut syndrome and Dravet syndrome. These rare but severe conditions usually appear in early childhood or infancy. Despite its long-standing history, and a wealth of contextual information about Cannabis and Cannabinoids, there are still many barriers to both research and actually receiving medical prescriptions. This is in part due to the illegality of Marijuana and the damage and stigma caused by the War on Drugs.

CBD oil can be bought relatively easily over the counter, as a health supplement. With a rapidly growing number of options available, it is of primary importance that quality and safety are made clear. The industry is becoming increasingly regulated in order to provide this, but making good choices still requires consumer education and investigation. 

Poor quality products tend not to list the concentration in mg or as a % on their packaging, and where it is listed – you should check the website for third party lab test certificates that prove the bottle contains what it says it does. Do your research and find a trusted supplier that is sustainable, ethical, provides high quality ingredients and is UK compliant.

The World Health Organisation (WHO) provided data, and stated a position, that pure CBD is safe for consumption. To overdose you would have to take around 20,000mg+ before it could be considered potentially harmful (for example, it can negatively affect the liver to have to process such a large amount). For comparison, an overdose of Ibuprofen is only 1000mg, which is around just 4-6 standard tablets.

Possible Drug Interactions

Many natural herbal and plant-based compounds have the potential to interact with medication depending on how it is processed by the body. This is why you should always consult your doctor before adding a new supplement to your daily regime. 

Most notably, CBD is a an inhibitor of an enzyme called cytochrome p450 (CYP450) which is found in the liver. These enzymes are especially important for your body’s ability to metabolise drugs into inactive or more active compounds. 

If you currently take a pharmaceutical drug that is processed by cytochrome p450 (they often come with a warning not to consume grapefruit or grapefruit juice which has the same effect), CBD may interfere with your body’s ability to process these pharmaceuticals, to varying degrees.

However, this does not rule out CBD as an option altogether. In fact in some instances, CBD may help increase the effectiveness of medication, thus lowering required dose. Depending on how the drug in question is processed, CBD could elevate or decrease the concentration of the active compound in your blood stream. Therefore your doctor may suggest extra blood monitoring in order to keep these drugs at a healthy level.

How Should You Take CBD?

How Do I Pick From Oils, Vapes, Smokes, Creams, Gummies etc?

Companies are getting inventive with how CBD is delivered – edibles like chocolates and coffees, topical skin creams, suppositories – Cannabis can be applied pretty much everywhere and anywhere. Deciding how you want to take it will come down to considering why you want to use it (what’s it for? Pain, pleasure, general health, sleep, anxiety etc), and factoring in metabolism / bioavailability.

Metabolism and things like body fat % affect how CBD is absorbed and processed by the body (how quickly it starts working, and for how long). Meaning that even though a product has x concentration on the bottle, this isn’t necessarily the amount you will end up absorbing as an individual. Each of the different methods of administration offers a different bioavailability – some products allow CBD to be more easily absorbed than others.

Bioavailability is also affected by the formulation of the product – for example oral CBD absorbs better when combined with fats, and topical CBD may absorb better when combined with Terpenes (e.g. beta-caryophyllene and myrcene, the Cannabis plant also naturally contains Terpenes), which are believed to help draw CBD across the skin barrier.

The below are very rough estimates, as metabolism depends on your unique composition, genetics and body fat percentage, however as a very general rule according to most studies:

Via The Lungs (inhaling, vaping, smoking - buds, liquids and concentrates)

Inhaling CBD directly into the lungs is one of the most bioavailable methods of administration. According to, if tobacco is not used (you can mix CBD buds with herbs such as spearmint instead), then the risk of lung cancer is almost the same as that of a non-smoker. Lung irritation can still occur, so use should be moderate. You can use a pen, joint, bong or vaporiser.

Onset of Action (how long it takes to work): 2-10 minutes with peak plasma levels around 3 minutes

Duration of Action (elimination half-life): 31 hours

Bioavailability (how much is actually absorbed into the blood): as high as 56% for an experienced user with proper technique (controlled and deep inhalation).

This method is personally my favourite, allowing for a rapid onset of action and longer duration of effects.  This is thanks to the large surface area and permeability of lung tissue. As with oxygen, the lungs offer a direct route to the systemic blood circulation, so that CBD can be transported around the body. More CBD is inhaled with each subsequent breath, providing a continuous dose of CBD that is quickly and efficiently absorbed. This is great for people that say they want to ‘feel something‘, as daily supplementation with oils and tablets is more like a multivitamin without any immediate effects.

Intranasal Sprays (Sativex / Nabiximols)

Sprays delivered up the nose offer transmucosal delivery, they are absorbed via the thin, vascular lining of the nasal cavity.

Onset of Action (how long it takes to work): 10 minutes

Duration of Action (elimination half-life): N/A not enough data

Bioavailability (how much is actually absorbed into the blood): estimated at 34-46%

Orally (edibles, oils, capsules, gummies, concentrates and powders, beverages)

When CBD is taken by mouth and swallowed, popular because it is an easy method of application.

Onset of Action: 30 to 120 minutes

Duration of Action: between 1-2.5 hours after a single dose, however repeated doses can mean it lasts up to 2-5 days.

Bioavailability: Around 10-20%, with some studies reporting as low as 46%

This bioavailability is due to the first pass effect: the compound has to pass through the digestive tract and is broken down in the stomach, intestines and the liver, which reduces its effectiveness. When CBD is absorbed by the GI tract it passes over to the liver via the hepatic portal vein, this is called hepatic first pass. Here it is metabolised by CYP450 enzymes, which are incredibly effective at breaking it down. Meaning that very little enters the systemic blood circulation. There are ways to get around this and its all about particle size and formulation, as explained below.

Different Oral Formulations:

In order to improve CBD absorption orally, many companies have tried to alter the size of the CBD molecule by making it smaller, and / or targeting its formulation by making it more water soluble. Cannabinoids are usually fat soluble, meaning they absorb as much as three times better when mixed with medium-chain triglycerides (MCTs) – healthy fats that improve uptake by the body. You can find our free healthy CBD recipe book here.

As the body consists mostly of water, lipophilic (fat-soluble) cannabinoids do not absorb well naturally (oil and water do not mix), making it difficult for them to dissolve. Improving the water solubility of CBD requires an emulsifier (breaks up fat droplets into smaller droplets) or surfactant (lowers the surface tension of a liquid), to achieve a finer dispersion of the oil into the water.

CBD particles measure around 2,000 nanometers, while human cells only absorb molecules smaller than 80 nanometers. Our liver naturally produces its own emulsifiers, however this preparation can also be useful for methods like sublingual administration which does not pass through the digestive tract. The 3 most common formulations for improving oral bioavailability are currently: Liposomic, Macroemulsions, Microemulsions and Nanoemulsions: 

1. Liposomal CBD

The cannabinoids can be made to dissolve in water by giving the spherical molecules a hydrophilic (water-attracting) outer-layer, whilst the inner cavity encapsulates the fat-soluble CBD. Scientists have also understood the importance of liposomes – a body of fat that surrounds or is attached to another molecule (a vitamin, pharmaceutical, or cannabinoid for example), allowing nutrients to be delivered more effectively.

2. CBD Macroemulsions

When CBD oil is mixed with a healthy fat such as MCT. The MCT carrier oil improves absorption via the GI tract, but the molecules remain large (> 1µ) and bioavailability is roughly on par with a sublingual dose.

3. CBD Microemulsions

The same as above, except that the droplets are broken down into a smaller size (about 1/10th the size of a macroemulsion). They require more surfactant to allow them to be more stable than macro-emulsions, as there is a larger surface area for absorption.

4. Nano Particles & Nanoemulsions

In a Nano-Particle formulation, the active particles (CBD oil) and its carrier oil are disrupted and dispersed / broken down using sonic frequencies. These break the droplet size down to a tiny size in a process known as ultrasonication. Because of their small size, the droplets can then easily pass through the walls of cell membranes, resulting in a higher level of absorption and efficacy. The downside is that the effect may not last as long, as the particles are also broken down more quickly.

In a Nano-Emulsion the nano-particles are blended with a surfactant that is equally small and designed to be easily absorbed by the body. This is still considered a relatively new technology, however theoretically it should allow for improved bioavailability where CBD can reach the system quickly and effectively, by increasing stability and absorption.

CBD as a nano-emulsion allows it to be absorbed at higher rates than other methods of delivery, the size therefore makes all the difference, with a 25 nanometer emulsion being absorbed more than 50%, whereas a 500-5000 nanometer (i.e. Liposomal) emulsion will have less than 20%.