Some of the biggest confusions surrounding CBD is the dosage; what quantity should an individual take and how often should they take it? There is no one right answer and potentially lots of wrong answers because there is no standardised dosage for non-medicinal CBD products. The CBD dose you will require depends on a number of factors, including, your body mass, the type of product you are using, the strength of the product, the reason you are taking it, whether you also take prescription medications, and whether you take it with food.
The labelling of CBD products can at best be confusing and at worst, misleading. Assuming that the label gives accurate information, it may give the CBD content as a percentage concentration and/or it may give the CBD content as a quantity in mg. It is important to note in most cases (but not all), that the quantity in mg is for the whole container and not per dose (whether that may be per dropper, spray, capsule, gummy, inhalation or application, depending on the product type). Some brands provide you with the mg of CBD per typical dose, others do not and expect you to do the sums yourself. The differences in labelling make it difficult to compare product prices in like for like comparisons. It can also make it difficult to determine how much of a product you need to take to get a set dose.
Does The Product Contain CBD?
Be aware, some products don’t actually contain a measured dose of CBD. There are Hemp Oil products on the market that state a figure in mg on the front label, which you’d be forgiven for thinking is the quantity of CBD, when in fact it is not. It is the quantity of hemp seed oil contained in the product, which may or may not contain CBD and other cannabinoids. Hemp seed oil has its own health benefiting properties, but it is not CBD. So please make sure that you are buying exactly what you want.
How to Calculate CBD Content – Getting the Right CBD Dose
To determine the strength of CBD per ml of product, we use the following calculation.
Number of mg on the label ÷ Volume of container in ml = Strength (CBD in mg per ml)
For example, lets calculate the strength of a 30ml bottle containing 1500mg of CBD:
1500mg ÷ 30ml = 50 CBD mg per ml
So the CBD strength in this example is 50mg per ml.
The same calculation shows that a 10ml bottle containing 500mg of CBD also = 50mg CBD per ml. Therefore, the number on the label does not tell you strength of CBD in the product, as shown in Table 1 below, which shows calculated examples of common CBD quantities for bottled products.
|Vol (ml)||Total mg||Strength (mg per 1ml)||%|
Table 1: Typical CBD dose strength and percentage calculations
Calculating the Percentage Concentration
It’s also important to understand percentage concentrations to be able to calculate doses and compare products effectively. To save you any complicated maths, Table 2 shows the calculated percentages of typical CBD quantities in the most common sized containers.
|mg on label|
Table 2: CBD strength percentage calculations
How to calculate the CBD dose per drop
CBD oils and tinctures are sold in bottles with a dropper that usually holds 1ml. However, the number of drops per ml often varies from brand to brand. You may need to calculate how much CBD is in each drop to get an accurate dose. To do that, you need to measure the full 1ml of oil and count the number of drops. You then need to divide the strength (number of mg per ml) by the number of drops to find the content of 1 drop.
Strength (number of mg per ml) ÷ Number of drops = Number of mg per drop
For example, if the dropper holds 20 drops and the strength is 50mg per ml, the calculation would be as follows:
50mg per ml ÷ 20 drops = 2.5mg
So, each drop in this example contains 2.5mg of CBD.
Calculating the CBD dose in Edibles and Vape Products
CBD edibles, such as capsules and gummies, are commonly labelled with the total quantity of CBD per container, with some brands also showing the quantity of CBD per edible. If the quantity per edible is not shown, you’ll need to divide the total CBD by the number of edibles to find the quantity of each one. Some people find it less complicated and easier to take a set dose of CBD from edibles.
CBD vape products are labelled with the total quantity of CBD per container but it is very difficult to determine the quantity of CBD being inhaled. Some brands have done the calculations for you and state the approximate dose of CBD per puff, but others leave the guesswork to the consumer.
Additional labelled products
CBD pastes are concentrated, pure plant extracts that have a strong earthy taste. All other CBD products have the plant extract (full-spectrum, broad-spectrum or CBD isolate) diluted in a carrier of some sort. CBD oils are diluted in edible oils, most commonly hemp seed, MCT (Medium Chain Triglycerides) or olive oil. These oils each have their own health benefits, which a quick Google search will show, so it can be difficult to decide which one is best.
A recent study found that hemp seed CBD oil had significantly greater antioxidant potential than olive CBD oil, which in turn showed significantly greater antioxidant potential than MCT CBD oils. 1. (Antioxidants help to protect cells against oxidative stress.) CBD can be degraded depending on temperature, light and auto-oxidation, and another study found that MCT CBD oil was less susceptible to oxidative degradation than olive oil or hemp seed oil. 2. Each type of carrier oil therefore has its own strengths and weaknesses. Further research is needed to determine if any carrier oil is superior and whether the type of carrier oil has an effect on the therapeutic action of the CBD itself. Until such times, it really is down to individual preference.
Hemp oil vs hemp extract
Some products that are labelled as containing Hemp or Hemp Seed oil do not actually contain cannabinoids and it can be very difficult for the consumer to know exactly what they are buying. Some products (particularly less expensive ones) are labelled as containing CBD without specific mention of CBD in the ingredients, instead listing hemp (or hemp seed) oil or extract, with no quantities are given. If no specific CBD or other cannabinoid quantities are given, it can be safely assumed that there are no cannabinoids in the product. In general, the more expensive a product, the higher the strength of CBD contained in that product. However, as stated previously, it is important to calculate the strength (in mg per ml or %) so that you can compare products and product brands.
Dose – How much CBD should I take? And how often should I take it?
Bioavailability of different product types
There is no hard and fast answer to this question. The dose required is dependent on a number of factors, including individual differences such as body mass, medications taken and the reason for taking it. The bioavailability (quantity available for use within the cells of the body) of the CBD is also very important. Only a portion of the CBD taken is available for the body to use. The formulation of the product and route of administration (the way it is taken) make a big difference to the bioavailability of the CBD.
Bioavailability of CBD is highest in Vape products and lowest in topical products
Research has shown that CBD from inhaled (vape) products have the greatest bioavailability ranging between 2% and 56%, 3. with an average of 31%. 4., 5. The bioavailability of products taken orally was less than 20%, 3. with an average of only 6%. 4. This is mainly because CBD taken orally goes through a process called first-pass metabolism where the CBD is broken down by the liver. 6. One study that compared vaporised CBD to orally delivered CBD at the same dose, found that the vaporisation increased the bioavailability of the CBD almost 10-fold. 2.
The bioavailability of sublingual (oromucosal) CBD products (e.g., sprays and tinctures) is not as high as inhaled products, but is higher than the oral products because of the reduced first-pass metabolism. 6. Topical or transdermal (through the skin) products also avoid first-pass metabolism but their bioavailability is lower than oral products because CBD’s hydrophobic nature limits diffusion across the aqueous layer of the skin. 6. The maximum concentration of CBD available was determined by the dose taken, but the time to reach the maximum concentration (between 0 and 4 hours) was not dose dependent. 7.
CBD should be taken with food
Research shows that taking CBD alongside a high fat meal can increase the bioavailability of CBD by as much as four times. 2., 4., 5., 7., 8. One study showed that taking CBD twice a day with food maximised bioavailability and achieved a steady state with moderate accumulation after multiple doses. 8. As the order of bioavailability from highest to lowest is: inhalation (vaporisation), sublingual/oromucosal, oral and topical/transdermal, the dose of CBD required will increase in the same order. Doses required will be lower for vape products, higher for sublingual and oral products, and highest for topical products.
CBD is not without its safety concerns and consumers should be aware that only licensed CBD products can make any medicinal health claims (i.e. Epidyolex for epilepsy). Suppliers or retailers should not make any claims, such as CBD being able to “cure”, “restore”, “prevent”, “avoid”, “fight” or “heal” any health condition.
The general advice is, that if you already take medication and want to take CBD too, you should start off with a very low dose and increase it slowly over a few weeks, while keeping a close eye out for potential side effects. But you should do this under the advice and supervision of your doctor for your own safety, particularly if you take prescription medications. The FSA *4 have stated that with the safety concerns known currently, CBD doses should not exceed 1mg of CBD per kg of body mass a day (or 0.5mg per kg of body mass, twice a day). However, it has been noted in the scientific literature that effective doses may be much higher. If you choose to take higher doses, you should only do so under the supervision and advice of your GP or specialist doctor.
2. Millar, S.A., Maguire, R.F., Yates, A.S. and O’Sullivan, S.E., 2020. Towards better delivery of cannabidiol (CBD). Pharmaceuticals, 13(9), p.219.
3. Nahtigal, I. & Blake, Alexia & Hand, A. & Florentinus-Mefailoski, A. & Hashemi, Haleh & Friedberg, Jeremy. (2016). The pharmacological properties of cannabis. Cannabis: Medical Aspects. 9. 481-491.
4. Pagano, S., Coniglio, M., Valenti, C., Federici, M.I., Lombardo, G., Cianetti, S. and Marinucci, L., 2020. Biological effects of Cannabidiol on normal human healthy cell populations: Systematic review of the literature. Biomedicine & Pharmacotherapy, 132, p.110728.
5. Nelson, K.M., Bisson, J., Singh, G., Graham, J.G., Chen, S.N., Friesen, J.B., Dahlin, J.L., Niemitz, M., Walters, M.A. and Pauli, G.F., 2020. The Essential Medicinal Chemistry of Cannabidiol (CBD). Journal of medicinal chemistry, 63(21), pp.12137-12155.
6. Lucas, C.J., Galettis, P. and Schneider, J., 2018. The pharmacokinetics and the pharmacodynamics of cannabinoids. British journal of clinical pharmacology, 84(11), pp.2477-2482.
7. Millar, S.A., Stone, N.L., Yates, A.S. and O’sullivan, S.E., 2018. A systematic review on the pharmacokinetics of cannabidiol in humans. Frontiers in pharmacology, 9, p.1365.
8. Taylor, L., Gidal, B., Blakey, G., Tayo, B. and Morrison, G., 2018. A phase I, randomized, double-blind, placebo-controlled, single ascending dose, multiple dose, and food effect trial of the safety, tolerability and pharmacokinetics of highly purified cannabidiol in healthy subjects. CNS drugs, 32(11), pp.1053-1067.