Glossary term

Half-life: Half-life is the time it takes for the amount of a substance in the body to reduce by about half.

AdvancedPharmacologySource quality: MediumLast updated: 29 June 2026

Why this term matters

Patients may encounter it when reading about interactions, accumulation or testing windows.

UK medical cannabis context

More useful in advanced safety and pharmacology content.

What not to assume

It does not tell someone exactly when effects or impairment end.

Careful wording: Avoid using half-life to promise a safe driving time.

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.

  • Technical chemistry / terminology review note. Used as terminology context only, not as standalone clinical guidance.
  • GOV.UK drug-driving law