The creatinine test measures serum creatinine, a product of muscle creatine turnover that is cleared almost entirely by glomerular filtration. Practitioners use it to screen kidney function before diet changes, monitor clients on high-protein or creatine-supplemented regimes, and track change over time. Creatine supplements, a large cooked-meat meal and hard training can raise it without a true change in filtration.
| Test type | Measured in a blood sample |
|---|---|
| Measurements required | Creatinine only |
| Sample and collection | Blood draw at a collection centre |
| Preparation | If your practitioner has requested the Baseline Health Check, fast for 8 to 12 hours before a morning collection (water is fine). |
| Turnaround | 3 to 5 business days |
| Available through | Urea, Electrolytes & Creatinine, part of the Baseline Health Check. Also in: Full Body Health Check. |
| Pricing | Included in the $99 Baseline Health Check |
| Results | Returned in the Vively practitioner platform, beside your client's other markers |
What are the Creatinine reference and optimal ranges?
| Typical lab reference | Vively optimal | |
|---|---|---|
| Men | 60 to 110 µmol/L | No separate optimal range |
| Women | 45 to 90 µmol/L | No separate optimal range |
Labs differ, so read the result against the range printed on the client's report (RCPA guidance). There is no Vively optimal range for creatinine, because where a client sits depends heavily on muscle mass.
Check a client's Creatinine result
Enter the value from your client's lab report to see where it sits against the typical lab range and the Vively optimal range.
A guide only, not a diagnosis. One result is a starting point: read it with symptoms, history and a repeat test. Labs differ, so check the result against the range on your client's report. Nothing you enter is stored or sent.
How do you arrange Creatinine testing through Vively?
- Get verified. Practitioners with a recognised qualification or membership (ATMS, NHAA, ANTA, Dietitians Australia, NSA, CMA or Ahpra registration) can request free practitioner access.
- Choose a panel. Log in to the practitioner platform and pick a panel that includes Creatinine, or build your own. It is included in the $99 Baseline Health Check.
- Client collects. Your client collects at a partner collection centre, with their request on their phone or printed.
- Review results. Results come back to you in the practitioner platform, beside your client's other markers, ready for the follow-up consult.
Which Vively panels include Creatinine?
Log in to the practitioner platform to view a panel in full, or build and save your own from 100+ tests and panels.
- Baseline Health Check74 markers across 11 lab groups$99
One fasting blood draw.
Full Blood CountUrea, Electrolytes & CreatinineLiver Function TestsCalcium, Phosphate & MagnesiumLipid StudiesDiabetes & Glycaemic StudiesIron StudiesThyroid Function Tests+3 moreLog in to view this panel - Log in to view this panelFull Body Health Check87 markers · Health checksPrice on sign-up
How do you read Creatinine without an optimal range?
No separate optimal range: creatinine output tracks muscle mass, so a lean older woman and a heavily muscled man can both be normal at opposite ends.
A single target would mislead in both directions. A steady rise across tests with no change in training, diet or supplements deserves more attention than a stable result near the upper limit.
When muscle mass or creatine use makes creatinine unreliable, KDIGO 2024 recommends adding cystatin C, which the client's GP can request, for an independent estimate of filtration.
What should Creatinine be read with?
- HighHigh creatinine, stable eGFR trend, high muscle mass
Often seen in strength-trained clients and creatine users; compare with previous results before acting.
- HighHigh creatinine with high urea
Possible dehydration or reduced filtration; repeat well hydrated and refer if it persists.
- LowLow creatinine, low albumin, recent weight loss
Possible low muscle mass or undernutrition, and eGFR will overestimate function here.
- ContextRising creatinine with rising uric acid or HbA1c
Worth discussing with the client's GP, as metabolic drivers of kidney disease tend to cluster.
What can affect a Creatinine result?
- Creatine supplements raise serum creatinine without a true change in filtration
- A large cooked-meat meal in the hours before collection
- Hard training or muscle injury in the previous 24 to 48 hours
- Dehydration
- Medicines that block tubular secretion of creatinine (trimethoprim, cimetidine) or reduce filtration pressure (NSAIDs, ACE inhibitors, ARBs)
- Pregnancy, which lowers it as filtration rises
When should you refer the client to their GP?
- Creatinine above the lab range on a repeat taken well hydrated and without recent hard training
- A clear rise from the client's previous result, especially with a falling eGFR
- Raised creatinine with high blood pressure, diabetes, swelling, reduced urine output or blood in the urine
- A climbing creatinine in a client who takes NSAIDs regularly
How should a client prepare for a Creatinine test?
Copy or print this to send to your client.
Preparing for your Creatinine test
- If your practitioner has requested the Baseline Health Check, fast for 8 to 12 hours before a morning collection (water is fine).
- Avoid hard training in the 24 hours before your test.
- Tell your practitioner if you take a creatine supplement, as it can raise your creatinine result.
- Take your pathology request to any of 4,000+ collection centres. Bring it printed or on your phone.
- Keep taking prescribed medicines as usual unless your doctor tells you otherwise.
- Results usually take 3 to 5 business days and come to your practitioner. Book your results appointment for after that.
How do practitioners use Creatinine with clients?
Record creatine supplements, training load and protein intake on the request so the result can be read in context. Kidney-friendly eating (less added salt, more vegetables, legumes and wholegrains, moderate red meat) suits most clients; reserve protein restriction for clients whose GP has confirmed reduced kidney function.
Creatinine FAQs
Should clients stop creatine before a creatinine test?
It helps when you need a clean read, but there is no agreed washout. Creatine raises serum creatinine and lowers the calculated eGFR without changing true filtration, and muscle stores take several weeks to fall after stopping. Record creatine use on the request, and if the result is high, let the client's GP choose between a longer washout and a cystatin C.
Why is creatinine reported with an eGFR?
Because creatinine alone misleads across age, sex and body size. Australian labs calculate eGFR from creatinine, age and sex with the CKD-EPI equation, turning the raw number into an estimate of filtration. A creatinine of 100 µmol/L is unremarkable in a muscular 30-year-old man and may reflect reduced filtration in a slight 75-year-old woman.
Can a naturopath, nutritionist or dietitian order creatinine through Vively?
Yes. Add it to a client panel on the Vively practitioner platform. It is part of Urea, Electrolytes & Creatinine in the $99 Baseline Health Check, and is also in Full Body Health Check. No account yet? Request free access.
Why can creatinine sit inside the range when kidney function has dropped?
Creatinine comes from muscle, so a client with low muscle mass makes less of it and can look normal while filtration is reduced. Low creatinine with low albumin and recent weight loss is the pattern to watch, because eGFR will overestimate function there. Compare against earlier results rather than the range alone.
Why are creatinine ranges different for men and women?
Men run higher (60 to 110 µmol/L) than women (45 to 90 µmol/L) because creatinine reflects muscle mass, which is on average greater in men. The same logic explains why a strength-trained woman can sit near the top of the female range without any change in kidney function. Trend the individual client over time.
References
- Royal College of Pathologists of Australasia. RCPA Manual: Creatinine.
- Pathology Tests Explained. Creatinine.
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International. 2024. Source
- Kidney Health Australia. Chronic Kidney Disease (CKD) Management in Primary Care. Source
- Inker LA, Eneanya ND, Coresh J, et al. New creatinine and cystatin C based equations to estimate GFR without race. New England Journal of Medicine. 2021. Source