Quick version
Creatine and creatinine are not the same thing, but they are related. Creatine is the energy source that makes muscles perform, while creatinine is the waste product that shows how well the kidneys filter the blood. Through a simple blood test, you can get valuable information about how your body metabolizes creatine and how your kidneys are doing. At the Test Clinic, you can easily book S-creatinine or Cystatin C to follow your values over time.
How do I measure creatine – and are creatine and creatinine the same thing?
Creatine is crucial for the body's energy supply, but many people wonder how to measure its levels and whether it has anything to do with the creatinine blood test. Here we explain the difference, how the tests are interpreted and what values are considered normal. You will also learn how you can easily monitor your levels with us at the Testmottagningen.
What is creatine?
Creatine is a natural substance that is formed in the liver, kidneys and pancreas from the amino acids arginine, glycine and methionine. It is stored in the muscles as creatine phosphate and acts as a quick energy store that allows the muscles and brain to perform efficiently even during short-term, intense loads. You can read more about the health effects of creatine in our main article Creatine – why it is good for the body.
Are creatine and creatinine the same thing?
No, but they are closely related. Creatine is a breakdown product of creatine – a type of waste product that is formed when muscles use creatine for energy. Creatinine is transported via the blood to the kidneys where it is filtered out through the urine. That is why S-creatinine (serum creatinine) is used as an important marker to assess the kidneys' filtration capacity.
An elevated creatinine value does not mean that you have too much creatine in your body, but that the kidneys are not filtering out creatinine quickly enough. This can sometimes be due to dehydration, high muscle mass or temporarily hard training – but in some cases also to impaired kidney function. Creatine supplements can also temporarily raise creatinine levels without it being dangerous.
How do you measure creatine and creatinine?
There is no simple blood test to measure creatine stores in the muscles, but you can indirectly see how the body metabolizes creatine by measuring S-creatinine or Cystatin C. These tests provide a clear picture of how effectively the kidneys are filtering the blood and can show whether your creatinine metabolism is functioning normally.
- S-creatinine: shows the concentration of creatinine in the blood and is used to calculate eGFR (glomerular filtration rate).
- Cystatin C: is a more sensitive and reliable measure of kidney function, especially in people with low or high muscle mass.
Reference values for creatinine (S-creatinine)
| Group | Reference range |
|---|---|
| Women | about 45–90 µmol/L |
| Men | approx. 60–105 µmol/L |
| Children | Varies depending on age and muscle mass |
The reference values may differ slightly between different laboratories.
How can I monitor my creatinine levels?
With us, you can easily book a referral-free test to measure your creatinine levels and assess kidney function. The tests are analyzed by accredited laboratories and supplemented with a medical assessment that explains what your values mean.
By following your values over time, you can:
- See how the body metabolizes creatine during exercise or dietary changes
- Assess the filtration capacity of the kidneys and detect changes early
- Evaluate the effect of dietary supplements or medication
When is it a good time to test creatinine?
A creatinine test can be valuable if you:
- Use creatine supplements regularly
- Have symptoms of fatigue, swelling or a change in urine volume
- Want to follow up on your kidney function when taking other medications
- Train hard or have a lot of muscle mass
Remember that creatine is an important energy reserve that helps muscles perform, while creatinine is the waste product that shows how effectively the kidneys filter the blood. By following your creatinine value, you get a clear picture of both kidney health and the body's energy metabolism.
Testing S-creatinine or Cystatin C is an easy way to take control of your health - whether you train hard, use creatine supplements or want to ensure that your kidneys are working properly. At the Test Clinic, you get quick testing without a referral, clear answers from an accredited laboratory and a personal doctor's assessment that explains what your results mean.
Take care of your body and follow your values over time - book your blood test today and get full insight into how your body metabolizes energy and filters waste products.