🫘 Kidney Health — Read Properly
For everyone · 6 markers · $83.25
with code CAMERON $92.50
High blood pressure, diabetes, a family history of kidney disease, long-term NSAID use — or you lift heavily and your eGFR came back looking alarming.
🩸 Order this exact panel — 10% off
All 6 markers load into your cart in one click. No doctor's visit, drawn at any Quest location in the US, results by email in about two weeks. Code CAMERON applies automatically.
Add all 6 markers — $83.25 → Open the full Bloodwork Vault →Why this panel
Kidney disease is silent until it's advanced, and the standard test is systematically wrong in muscular people. This panel measures function the way it should be measured in this population and adds the urine test that catches damage years before eGFR moves.
What this panel can settle, and by what logic
Six markers, and the whole design rests on one fact: creatinine is a muscle measurement that is used as a kidney measurement.
- Cystatin C with eGFR beside the creatinine on the Comprehensive Metabolic Panel (CMP) settles whether a low eGFR is you or your kidneys. Creatinine is produced from muscle at a rate that depends on muscle mass, diet and turnover, which is why it is used to estimate body composition as well as renal function Ávila 2025. Cystatin C is produced by nucleated cells at a far more stable rate. Where the two estimates disagree, the direction of the discordance is itself information about which one to believe Wang 2023, and in a muscular person the creatinine estimate is usually the wrong one.
- Urinalysis, Routine finds damage that function tests cannot. Protein or blood appearing in urine is a structural finding, and it shows up while eGFR is still entirely normal. This is the $10 marker on the list and it is the one that most often changes what happens next.
- Uric Acid connects the kidney result to the metabolic one. Urate is cleared renally, so it rises when clearance falls, and it also rises with insulin resistance independently. A high urate with a normal cystatin C eGFR is pointing at metabolism, not at the kidney.
- The Complete Blood Count (CBC) with Differential carries the consequence. Failing kidneys produce less erythropoietin, so a normocytic anemia developing alongside a falling eGFR is corroboration that the eGFR is real rather than analytical.
What it cannot settle, and what would
It cannot tell you whether this is acute or chronic, and that is the first question a nephrologist asks. One creatinine is a snapshot of a production and clearance balance Ávila 2025; it carries no date stamp. A creatinine of 1.4 mg/dL that has been there for 5 years and one that arrived last week look identical on this report and mean completely different things — the first is a condition to manage, the second is an event to investigate this week. Only a previous result, or a repeat draw a few weeks later, distinguishes them. Chronic kidney disease is defined by abnormality persisting at least 3 months, which is a statement about time that no single draw contains.
It cannot find the cause of anything it detects. Obstruction, stones, cysts, reflux and a shrunken kidney are ultrasound findings. Glomerulonephritis is a biopsy diagnosis. A panel can tell you function has fallen and cannot tell you why Wang 2023.
A dipstick Urinalysis, Routine is not albuminuria quantification. The test that tracks early diabetic and hypertensive kidney damage is a urine albumin to creatinine ratio on a first-morning sample, reported as a number in mg/g. A dipstick reporting ‘trace protein’ is a prompt to buy that test, not a substitute for it.
And it cannot tell you that creatine is harming you, because the evidence says it is not. Creatine raises measured creatinine by adding to the substrate pool, not by damaging nephrons, and reviews of bodybuilding practice find little evidence that moderate creatine supplementation or high protein intake poses a risk to people with normal kidney function Tidmas 2022. What it does is corrupt the measurement, which is the whole reason Cystatin C with eGFR is on this panel.
Draw conditions that decide whether the money is wasted
Every marker here except the Complete Blood Count (CBC) with Differential moves with what you did in the preceding 3 days, and all of them move in the alarming direction.
- 72 hours clear of hard training. Muscle work raises creatinine production directly Ávila 2025, and the size of the effect is enough to move an eGFR across a reporting threshold in someone with entirely normal kidneys. Leg day before a kidney panel is the commonest self-inflicted scare in this audience.
- Hydrate as you normally would, and do not fast dry. Creatinine changes measurably across a single working day with fluid loss and heat exposure, which is exactly what the sugarcane workweek study was built to measure Dally 2021. Arriving dehydrated concentrates creatinine, albumin and hemoglobin together.
- Stop creatine for at least 3 weeks if the eGFR is the reason you are testing. Supplementation raises serum creatinine while leaving kidney function unchanged Tidmas 2022, so a result taken on it answers a question you did not ask. If you will not stop, buy the Cystatin C with eGFR and read only that.
- First-morning urine for the Urinalysis, Routine, collected midstream. A dilute afternoon sample can miss protein that a concentrated morning one shows.
- Not within 2 weeks of an illness, because hs-CRP (High-Sensitivity C-Reactive Protein) on this panel is an acute-phase protein and a post-viral value says nothing about chronic inflammatory burden Luo 2023.
How you would know it answered your question, and what each pattern means next
Four patterns. Note that three of them end in a second draw, because a kidney result is a rate of change and one point has no rate.
- Low creatinine-based eGFR with a normal Cystatin C with eGFR eGFR: the commonest result in this audience, and it is muscle rather than disease Wang 2023 Ávila 2025. Nothing to repeat. Use cystatin C as your baseline from now on.
- Both estimates low: repeat in 2 to 4 weeks before doing anything else. That interval is what separates an acute insult — dehydration, an anti-inflammatory course, a viral illness — from a persistent fall, and the second draw is worth more than any additional marker on the first Dally 2021.
- Protein or blood on Urinalysis, Routine with a normal eGFR: this is the finding that does not wait for a repeat. Take it to a doctor and ask for a urine albumin to creatinine ratio; damage precedes function loss by years and this is the window in which it is treatable.
- Falling Cystatin C with eGFR eGFR across two draws: the panel has done its job and the next steps are not blood. Imaging to find a structural cause and a nephrologist to interpret it Wang 2023, because nothing on this list can name the disease.
Sources read for these sections
- Wang Y, et al. Discordance Between Creatinine-Based and Cystatin C-Based Estimated GFR: Interpretation According to Performance Compared to Measured GFR. Kidney Medicine 2023 · PMID 37753251
- Ávila M, et al. The Metabolism of Creatinine and Its Usefulness to Evaluate Kidney Function and Body Composition in Clinical Practice. Biomolecules 2025 · PMID 39858438
- Dally M, et al. Sugarcane Workweek Study: Mechanisms Underlying Daily Changes in Creatinine. Kidney International Reports 2021 · PMID 34901578
- Tidmas V, et al. Nutritional and Non-Nutritional Strategies in Bodybuilding: Impact on Kidney Function. International Journal of Environmental Research and Public Health 2022 · PMID 35409969
- Luo H, et al. A Practical Guide to Adjust Micronutrient Biomarkers for Inflammation Using the BRINDA Method. Journal of Nutrition 2023 · PMID 36792034
The 6 markers — and why each one is here
Not muscle-dependent — the only valid kidney read if you lift or take creatine
Creatinine, urea and electrolytes — the standard comparison
Anemia is an early consequence of declining kidney function
Ordering the panel tells you your numbers. The protocol tells you what to do with them — why creatinine is a muscle-mass test that mislabels lifters and creatine users, the cystatin C result that settles it, and the high-protein myth the evidence doesn't support.
Join Skool — $10/mo →What this panel is ordered to decide
A panel is a set of numbers until it settles something. These are the decisions this one feeds — each links the pathway it belongs to, what that pathway claims, and what its test list is read for.
Cystatin-C reads kidney function independently of muscle mass, which matters if you're muscular — creatinine systematically overstates decline in that group and understates it in the frail.
Related panels
Frequently asked questions
6 markers: Cystatin C with eGFR, Comprehensive Metabolic Panel (CMP), Urinalysis, Routine, Uric Acid, Complete Blood Count (CBC) w/ Differential, hs-CRP (C-Reactive Protein, High Sensitivity).
$92.50 before discount, $83.25 with code CAMERON applied automatically. Individual markers add a one-time $10 draw fee. Ordered through Marek Diagnostics and drawn at any Quest Diagnostics location in the US.
No. These are ordered direct-to-consumer through Marek Diagnostics — you order online, walk into a Quest location, and results are emailed to you in about two weeks. No physician visit or insurance required. Not available in NY, NJ or RI.
Fast 9–12 hours. Stay 72 hours clear of hard training and hydrate normally — dehydration and recent exercise both distort the result.
A normal cystatin C eGFR with a scary creatinine eGFR means you're muscular, not sick — that's the most common finding here in this community. Protein or blood in the urine needs a doctor regardless of eGFR. Raised uric acid points at metabolic problems and gout risk. A genuinely falling cystatin C eGFR across two draws is the finding that matters, and it needs a physician.
Where this goes next
This page is how to read the panel. What to DO about each result — the dosing, the order to correct things in, the week-by-week schedule and what to retest — is a lesson inside Skool.