Preparation guide
What Can Affect Laboratory Results?
Food, drinks, medicines, supplements, exercise, timing, illness, and collection conditions can affect selected laboratory results.
Why is this important?
Understanding the purpose and limits of laboratory information can support a more informed conversation with a qualified healthcare professional.
How laboratory testing relates
The relevant factors vary by test. Tell the requesting professional and laboratory about medicines, supplements, and whether preparation instructions were followed.
Before testing
Preparation is test-specific. Follow the instructions given for the exact test and contact the laboratory if fasting, timing, medicines, or specimen collection is unclear. Do not stop medicines unless a qualified professional tells you to.
Sources & further reading
- MedlinePlus, U.S. National Library of Medicine: Laboratory Tests
External authoritative patient reference · Verified 2026-08-10
- MedlinePlus, U.S. National Library of Medicine: How to Prepare for a Lab Test
External authoritative patient reference · Verified 2026-08-10
Prefer collection at home?
Request Home Collection and our laboratory team will confirm the requirements and appropriate arrangements.
Request Home Collection