Glossary term

Efficacy: Efficacy means how well a treatment performs under controlled conditions, especially in clinical trials.

UsefulResearchSource quality: MediumLast updated: 29 June 2026

Why this term matters

Patients reading research coverage often confuse efficacy with effectiveness.

UK medical cannabis context

Important for interpreting NICE decisions and trial results.

What not to assume

High efficacy in a trial does not automatically mean the same outcome in routine care.

Careful wording: Avoid treating efficacy as a patient guarantee.

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.