If you are new to medical cannabis, the labels can be confusing: THC, CBD, CBN, CBG, plus ratios and percentages. These are cannabinoids — the active compounds in cannabis — and knowing the basics helps you have a more useful conversation with your practitioner. This guide explains what each of THC, CBD, CBN, and CBG is generally associated with, in plain language. It is general educational information, not medical advice, and it is not a recommendation to use any particular product — that is your practitioner's call.
Key takeaways
- THC is the main intoxicating cannabinoid — associated with pain, nausea, and appetite.
- CBD is non-intoxicating — associated with anxiety and inflammation.
- CBN is a minor cannabinoid often discussed in relation to sleep.
- CBG is a minor "parent" cannabinoid being studied for inflammation.
- Ratios and dosing matter — which is right for you is a decision for your practitioner.
What is THC and what is it associated with?
THC (tetrahydrocannabinol) is the main intoxicating cannabinoid — it is what produces the cannabis "high." In a medical context it is most often associated with pain, nausea, and appetite stimulation. Because it is intoxicating, THC also has dose-dependent effects on alertness and coordination, which is why dosing and timing matter and why driving impaired is illegal. A higher-THC product is not automatically "stronger medicine" — the right amount is the one that helps your symptoms without unwanted effects, which is exactly what a practitioner helps you find.
What is CBD and how is it different from THC?
CBD (cannabidiol) is non-intoxicating — it does not produce a high — and is most often associated with anxiety and inflammation. Many medical products are described by their THC:CBD ratio, because CBD is sometimes used to balance or moderate the effects of THC. CBD can also interact with some medications, which is one more reason to involve a practitioner rather than self-selecting. The takeaway: THC and CBD are different tools, and many people use a combination; the ratio is part of what your practitioner helps tailor to you.
What are CBN and CBG?
CBN (cannabinol) and CBG (cannabigerol) are "minor" cannabinoids — present in smaller amounts and less studied than THC and CBD. CBN is often discussed in relation to sleep (it forms as THC ages), and CBG is sometimes called the "parent" cannabinoid because others form from it; it is being studied for inflammation. The evidence for these minor cannabinoids is still developing, so claims should be read with caution. Health Canada's clinical resource for health professionals summarizes the peer-reviewed literature on cannabis and the cannabinoids, and a practitioner can put any of this in context for your situation.
What is the entourage effect?
You may see the term "entourage effect" on products or in forums. It refers to the idea that cannabinoids and other compounds in cannabis — including terpenes, the aromatic molecules that give strains their smell — may work together, so a full-spectrum product behaves differently from an isolated single cannabinoid. It is a plausible and widely discussed concept, but the evidence is still developing and it is sometimes overstated in marketing. The practical takeaway is simple: do not assume "more cannabinoids" automatically means "better." What matters is how a given product affects your symptoms, which is something to evaluate with a practitioner rather than infer from a label.
How do you read a cannabis product label?
Once you have a medical document, product labels become easier to make sense of with a few basics in mind.
- THC and CBD content is shown as a percentage (dried flower) or mg per unit (oils, capsules).
- A THC:CBD ratio (for example 1:1 or 1:20) tells you the balance between the two.
- Minor cannabinoids like CBN or CBG, if present, are usually listed separately.
- Higher percentage is not the same as "better" — it just means more concentrated.
- When unsure, your practitioner or a licensed seller can help you interpret a label.
How do you start with a new cannabinoid product?
Whatever the cannabinoid, the golden rule is start low and go slow. Begin with a small amount, give it time to take full effect — minutes for inhaled forms, but an hour or more for oils and capsules — and avoid the common mistake of taking more too soon because nothing seems to be happening. Change one thing at a time so you can actually tell what is doing what: the cannabinoid, the ratio of THC and CBD, the dose, the form, or the timing. It helps to start in a comfortable setting with nothing important to do afterward, especially with any THC. Keep a simple note of what you took and how you felt, so patterns become clear. This measured approach matters because individual responses vary widely, and the amount that suits someone else may be quite wrong for you — finding your own level is the whole point of going slowly.
What are the risks and side effects to know?
The two main cannabinoids carry different cautions. THC is intoxicating and can cause drowsiness, dizziness, dry mouth, a faster heartbeat, and — particularly at higher doses — anxiety or paranoia in some people; it also impairs alertness and coordination, so you must never drive while affected. CBD is non-intoxicating and generally better tolerated, but it is not side-effect-free: it can cause tiredness, appetite or digestive changes, and, importantly, can interact with other medications. The minor cannabinoids like CBN and CBG are less studied, so their effect profiles are less certain. A practical theme runs through all of this: the balance of THC and CBD shapes both the benefits and the downsides, which is why higher potency is not the same as better medicine. Starting low, going slow, and reviewing with a practitioner is how you keep these effects small while finding what genuinely helps.
Can cannabinoids interact with your medications?
Yes, and this is one of the most important and least appreciated points. Both THC and CBD are processed by the same family of liver enzymes that handle many common medications, so they can change how much of a drug ends up in your system — raising or lowering its effect. CBD in particular is known to affect the levels of certain medications, including some blood thinners and anti-seizure drugs, which is why precise, supervised use matters in those situations. This is exactly why your practitioner needs your full medication list, including over-the-counter products and supplements, before you start: it lets them flag interactions in advance rather than discovering them the hard way. It is also why you should not treat cannabinoids as harmless just because they are natural. Used with a complete picture of your other medications, cannabinoids can be fitted into your care safely; used blindly alongside other drugs, they carry avoidable risk. If you take any medication with a narrow safety margin, or one your doctor monitors with blood tests, raise it specifically before you begin, because those are the cases where an interaction matters most and where professional oversight makes the biggest difference.
How do you choose the right cannabinoids for you?
You do not have to figure this out alone — and you shouldn't. The right cannabinoids and ratios depend on your condition, your other medications, and how you respond, which is why this is a practitioner-guided decision. Once you have a medical document, you can buy products labelled with their THC, CBD, and sometimes CBN or CBG content from a licensed seller, or grow your own under the ACMPR. Bring your symptoms and questions to your assessment; understanding these basics just helps you and your practitioner choose well together.