Has anyone gotten a cystatin C blood test for renal function? It's one of the top predictors of chronological age

before and after rapamycin?

I personally did after, and it lined up with my regular egfr using creatinine
Its just a better way to calculate egfr that doesnt fluctuate from creatine levels

1 Like

Yeah - so my eGFR (without Cystatin C test) came back at 73. Then I had the Cystatin C test and eGFR comes back at 115.

Could the initial reading have been low because of high creatinine levels?

Asked my Kaiser PCP for this test, denied:

‘Cystatin-C is not a routine screening blood test.
Your kidney function was checked with the creatinine blood test.’

I have low creatinine. But 0.77 mg/dL => 0.68 umol/L which is not super-low.


Test Cystatin C With Glomerular Filtration Rate, Estimated (eGFR)
LabCorp Test Number: 121265
CPT: 82610

LabCorp billing to insurance in the NY area on 03/17/2023 $202.65

Through 3rd party service

LabCorp test 121265 through

Life Extension cost $99.00

Through Marek Diagnostics $79.00
Look at another posting their was a discount code posted

At discounted labs $57.49

1 Like

Cystatin C is currently $40 through Ulta Labs. They use Quest Diagnostics. That’s the lowest price I could find for self testing.


I would try asking your doctor to order it; it usually is covered. I had to explain to my Dr. what it was.

Yeah I did it through Ulta for $40. Definitely the best deal out there

Here is the Ultra Lab link.

Thank you Vlasko

Creatinine is subject to increasing through metabolism. So be careful about delays between giving a blood sample and the test being done.