THC (tetrahydrocannabinol) is the primary psychoactive compound in cannabis responsible for the plant's characteristic “high.” It's one of over 100 cannabinoids found in cannabis and plays a central role in how cannabis affects mood, perception, and cognition.
Key Takeaways
Main psychoactive component of cannabis
Found in flowers, concentrates, offset-4 transition-colors hover:underline" title="Learn more about Edibles">edibles, and oils
Impacts mood, appetite, memory, and coordination
THC percentage (%) indicates potency
Legal limits and product availability vary by region
What is THC?
THC stands for tetrahydrocannabinol, a cannabinoid compound that activates receptors in the brain to create intoxicating effects. It is most commonly associated with delta-9-THC, which is the form found in most cannabis products.
In products like flower and concentrates, THC is usually expressed as a percentage by weight. For edibles and oils, it's labeled in milligrams. THC content is a key metric consumers use when selecting cannabis products.
How THC Affects You
THC binds to CB1 receptors in the brain, altering neurotransmitter activity and leading to effects such as:
Euphoria or mood elevation
Altered perception (e.g., colors, sound, time)
Increased appetite
Relaxation or drowsiness
Impaired short-term memory or coordination
Effects vary by individual. Higher THC doses may increase the likelihood of anxiety, dry mouth, red eyes, or confusion. Experienced users often develop a tolerance over time.
CBD (cannabidiol), another major cannabinoid, may moderate the intensity of THC's effects when both are present.
THC Potency: How It's Measured
Flower: Measured in percentage (%). Example: 20% THC in dried flower equals 200 mg per gram.
Edibles/Oils: Measured in milligrams (mg). Example: 10 mg THC per gummy.
Concentrates: Ranges from 50% to over 90% THC depending on refinement.
Cannabis products are typically lab-tested to confirm potency and safety. THC content appears on labels and online listings to help consumers gauge product strength.
Contextual Use Examples
“This strain has a high THC content—best for experienced users.”
“Always check the THC percentage before consuming a new product.”
“These gummies contain 5 mg THC per piece for a mild effect.”
Canadian Legal Guidelines
Legal for adults 19+ (18+ in Quebec)
Maximum public possession: 30 grams of dried flower or equivalent
THC products must be purchased from licensed retailers
Edibles were formerly capped at 10 mg THC per package; new rules now allow multi-packs up to 100 mg total
Related Glossary Terms
FAQs
Q: What does THC do?
A: THC produces the psychoactive effects of cannabis—the “high.” It affects the brain by altering neurotransmission, which influences mood, perception, and coordination.
Q: Is THC legal in Canada?
A: Yes. THC is legal for adult use across Canada. Legal products must be sold through authorized retailers and follow federal regulations on packaging, labeling, and dosage.