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The Core Problem
- Drug tests detect THC metabolites — not impairment
- Having a valid prescription does not exempt you from a positive test result
- Roadside tests can lead to arrest even if you are not impaired
- Workplace drug testing policies vary — some zero-tolerance approaches exist in safety-critical roles
Drug testing is one of the most practical challenges for UK medical cannabis patients in employment and daily life.
Detection Windows and Practical Advice
- Urine: 3-30 days depending on frequency and metabolism
- Blood: typically 1-7 days
- Hair: up to 90 days
- Saliva: 24-72 hours
- Carry your prescription documentation. Discuss potential drug testing with your clinician before starting treatment.
CBD-only formulations significantly reduce — but do not eliminate — the risk of a positive test. For safety-critical roles, discuss with your occupational health team before starting cannabis treatment.
