What is Cystatin C?
a more precise kidney measure
Cystatin C is a protein that kidneys filter at a steady rate. It is a more precise measure of kidney function than creatinine because it is not affected by muscle mass.
The value is especially useful in older adults, in people with extreme muscle mass (athletes or frail), and in early kidney function decline.
Test facts
- Unit
- mg/L
- Sample
- Serum
- Fasting
- No fasting needed
- Turnaround
- 2 days
What does low Cystatin C mean?
Low values are favourable.
What does high Cystatin C mean?
High cystatin C reflects reduced kidney function.
Panels that measure Cystatin C
- Deep Baseline
- Longevity Full
- Kidney Check
More markers in the same area
Launching in Stockholm in 2026.
Want to know when you can order?
This is general information about the marker, not an assessment of your values and not medical advice. Last updated: May 2026.