How to prepare
No fasting is required. Drink water as normal. Unlike creatinine, cystatin C is not significantly affected by recent diet, exercise, or muscle mass changes. Let your practitioner know about corticosteroid medications or thyroid conditions.
After the test
Share your results with your GP or relevant specialist. Cystatin C is typically interpreted alongside creatinine and eGFR as part of a broader kidney function assessment.
Your test results will be available in your private dashboard. If there are any urgent issues, we'll let you know so you can follow up with your health professional.
Understanding results
Results are reported in milligrams per litre (mg/L). Your result report includes the reference range that applies to your sample, and your practitioner can explain what your number means in your context. Higher levels indicate lower kidney filtration capacity. Cystatin C can be elevated by corticosteroid use and thyroid dysfunction independently of kidney function.