When searching online for an accurate CBD dosage guide, it can be difficult to know where to look. There is lots of information out there, and lots of it comes across way more complicated than it needs to be! Forget all of that, it’s actually really simple…

Every single person is unique, meaning they will each require a different amount of CBD in order to reap the benefits they are seeking. Additionally, everybody is seeking different benefits! This can also influence how much CBD they choose to take, and how they may experience the effects of different dosages.

Lets go over this in some more detail below:


Titration is the process of slowly increasing your dosage of a substance. When it comes to CBD, this is simple: start low, and increase your dosage weekly until you get the desired effect. If you begin to encounter side effects, but you have also observed some benefits, then reduce your dose. If you begin to encounter side effects, but you have not experienced any benefits, then stop your dosing altogether.

Everyone will need a different CBD dose based on their weight, and their individual biology. Each body absorbs substances very differently, so it is impossible to accurately predict what everybody’s perfect dosage will be. This is why titration is so important. Before you start using CBD, you should define your goal: what is your desired outcome from using CBD? You should then keep a diary which records how you are experiencing your CBD usage. For example: if your desired goal is to reduce pain, then keep a diary which records your pain levels from week to week. Keep score of your pain on a scale of 1-10, and see how this changes as you increase your CBD dose. Set a goal that states where on this scale you would like to reach, and then titrate towards this goal. And remember - be realistic! Don’t expect a miracle to happen straight away; these things can take time.

Take a look at the table below for a guide on where you might want to begin your titration journey, or where you may find your optimum dosage:

Daily Dosage Calculation
Under 11.4kg11.5-20.4kg20.5-38.5kg38.6-68kg68.1-108.9kgover 109kg

Here is some additional information showing approximately how much CBD you will get per 1ml of CBD oil, depending on which bottle you have:

  • - 300mg/30ml Bottle is approximately 10mg CBD per 1ml
  • - 500mg/30ml Bottle is approximately 17mg CBD per 1ml
  • - 1000mg/30ml Bottle is approximately 33mg CBD per 1ml
  • - 2000mg/30ml Bottle is approximately 66mg CBD per 1ml
  • - 3000mg/30ml Bottle is approximately 100mg CBD per 1ml
  • - 6000mg/30ml Bottle is approximately 200mg CBD per 1ml


Pharmacokinetics is the branch of pharmacology concerned with the movement of drugs within the body. Substances like CBD absorb within the body in different ways, which can affect the bioavailability of different CBD products. Bioavailability simply refers to the proportion of a drug or substance which enters the circulation when introduced into the body and so is able to have an active effect. So if a CBD product has a high bioavailability, this means more of the CBD is able to be absorbed into the bloodstream and can therefore have more of an effect.

CBD Edibles If you ingest CBD in the form of gummies, chocolates, drinks etc. then most of what you ingest gets broken down in the gut and filtered out through the liver. This process essentially filters out a large portion of the CBD, meaning the bioavailability is drastically reduced. Additionally, it takes longer for the CBD to get into the bloodstream, meaning it can take longer for you to notice any effects. Studies have suggested the bioavailability rate of CBD edibles to be somewhere between 4% and 20%.

CBD Oils or E-Liquids Using CBD sublingually (drops under the tongue), vaping a CBD e-liquid tends to be more effective. The bioavailability of these types of products is much higher, meaning you are essentially getting better value for money.

CBD Topicals CBD creams or ‘topicals’ are applied to the skin, meaning the CBD does not actually enter the bloodstream at all. However, this does not necessarily mean the bioavailability is low. It would be unfair to compare CBD topicals to other types of product in this way, since the way in which they work is quite different. As we apply the product, the cannabinoids are deeply absorbed into the skin and will then interact with cannabinoid receptors underneath the skin's surface. This can be a very effective method, as CBD is not ‘lost’ or ‘filtered out’ when passing through the skin’s surface towards these cannabinoid receptors. To find out more about this topic, look up ‘1st pass pharmacokinetics’, or check out this summary from the World Health Organisation: https://www.who.int/medicines/access/controlled-substances/5.2_CBD.pdf

Drug interactions

In the human body, we have Cytochromes P450 (CYPs) - these are enzymes or proteins that oxidise steroids, fatty acids, and other chemical substances [1] [2]. They are vital for the clearance of various compounds in the body, and for breaking down hormones. This essentially means that CYPs play a major role in our drug metabolism. Many drugs may increase or decrease the activity of various CYP proteins, which will affect the way in which an individual experiences the effects of that drug. They can also affect the way in which other drugs interact with the body, when multiple substances are taken at the same time [1] [2].

With sufficient dosages, CBD will temporarily deactivate these CYP450 enzymes, therefore altering the way in which we metabolise a wide range of compounds. This includes THC: the cannabinoid from Cannabis that causes psychoactive effects [1] [2].

Research shows that CBD is metabolised by CYP450, whilst also functioning as a ‘competitive inhibitor’. This essentially means that both of these compounds are deactivating each other. This means that CBD is preventing CYP450 from metabolising other compounds (like we mentioned previously with THC). The extent to which CBD can have this effect depends on how much CBD is taken, and the method that is used to ingest it. With a low dose, it will likely have no noticeable effect on CYP activity [2].

Cancer Treatment: In cancer treatment, doctors have to use very precise dosing of chemotherapy. If a patient chooses to use CBD alongside their chemotherapy treatment, the CBD may inhibit the CYP metabolism of the chemotherapy agent, which could cause the dosage to accumulate within the body to highly toxic levels. However, there have been very few reports of this happening. It is thought that broad or full-spectrum CBD (with a combination of synergistic cannabinoids) may interact differently than a CBD isolate would [2].

Epilepsy Treatment: Some epileptic patients have found issues when using CBD alongside their anti-seizure medication. However, studies have concluded that CBD is in fact a safe and effective treatment of refractory epilepsy in patients receiving the drug clobazam. In this conclusion, the importance of monitoring the levels of clobazam in the blood was heavily emphasised [6].

A study showed that CBD interacts significantly with these anti-epileptic drugs: clobazam, rufinamide, topiramate, zonisamide, and eslicarbazepine. The study results emphasized the importance of monitoring the levels of anti-epileptic drugs in patients also being treated with CBD. The researchers found that, when increasing the patient’s CBD dose, there were increases in serum levels of topiramate, rufinamide, and desmethylclobazam (which is an active metabolite of clobazam), and a decrease in levels of clobazam. Additionally, they found a significant increase in serum levels of zonisamide and eslicarbazepine [6].

Multiple Sclerosis (MS): Treatment Another study aimed to assess the potential drug-drug interactions between Sativex (a CBD/THC drug used to treat MS), in combination with Rifampicin (a CYP450 inducer, and ketoconazole or omeprazole (a CYP450 inhibitor). They found that using rifampicin alongside the THC/CBD drug altered the serum levels of the THC/CBD respectively compared to using a single dose of the THC/CBD drug alone. Using ketoconazole alongside the THC/CBD drug increased the serum levels. Using omeprazole alongside the THC/CBD drug had no significant effects on the serum levels. They found that the THC/CBD drug was well tolerated by all of the study subjects alongside rifampicin, ketoconazole, and omeprazole. They concluded from this study that there was likely to be little impact on these other drugs when used alongside the THC/CBD drug, but that potential effects should be taken into consideration when co-administering these [3].

Hexobarbital: Another study found that using CBD reduced the bioavailability of the drug hexobarbital. Hexobarbital is a drug known to have hypnotic and sedative effects. It was subsequently used in the 1940s and 1950s as an anesthetic for surgery. In the study, the drug increased fatigue and tremor, impaired eye-tracking performance, and altered brain activity. They found that the effects of this drug were not affected by the use of CBD [4] [5].


  1. https://www.medmen.com/blog/health/can-cbd-help-with-eczema
  2. https://www.projectcbd.org/medicine/cbd-drug-interactions/p450/
  3. https://pubmed.ncbi.nlm.nih.gov/23750331/
  4. https://pubmed.ncbi.nlm.nih.gov/7389248/
  5. https://ascpt.onlinelibrary.wiley.com/doi/abs/10.1038/clpt.1980.139
  6. https://profreg.medscape.com/px/sso/oauthlogin?oauth=1&client_id=29210617-47A2-49CB-A6C8-38A252ED3F14&response_type=code&redirect_uri=https%3A//www.mdedge.com/services/medauth/authenticated&state=https%253A%252F%252Fwww.mdedge.com%252Fneurology%252Fepilepsyresourcecenter%252Farticle%252F128497%252Fepilepsy-seizures%252Fhow-does-cannabidiol&status=5ed0eef3a91de

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