Glossary term

THC: THC is the cannabinoid best known for causing intoxication or a “high”. NHS public guidance says it is the chemical in cannabis that makes people high, and also notes that the more THC a product contains, the greater certain risks can be.

EssentialCannabinoidsSource quality: HighLast updated: 29 June 2026

Why this term matters

It is one of the most important patient terms in the whole glossary.

UK medical cannabis context

In UK driving law, THC sits within the zero-tolerance-style specified-drug framework, though a medical defence may apply if the medicine is prescribed and taken correctly.

What not to assume

THC content is highly relevant to impairment, psychiatric side effects, dependence risk and driving discussions.

Careful wording: Avoid reassurance such as “medical THC doesn’t make you high”.

Related glossary terms

Related MCPH pages

Sources and review notes

This entry is educational vocabulary, not medical advice. Suitability, prescribing, product choice and monitoring belong with a qualified clinician or pharmacist.