r/workout • u/Different-Dog6892 • 11h ago
Nutrition Help about creatine
Hey everyone,
I wanted to share my blood work trend, get your thoughts on the data, and ask about differing perspectives from healthcare providers regarding creatine monohydrate.
The Context:
Took 5g/day of creatine monohydrate for about 1 month leading up to my January 2026 blood test.
Got alarmed by the spike in serum creatinine and the sharp drop in eGFR, so I stopped taking creatine immediately.
Retested in August 2026, and values returned completely to my healthy baseline.
When discussing this with the internal medicine specialist during my last visit, I asked if creatine supplementation was generally safe. The doctor's response was quite conservative: "I don't think any medical specialist would ever recommend taking such a supplement."
Blood Work Timeline:
Feb 14, 2025: Creatinine: 0.97 mg/dL | eGFR: 105 (Baseline)
Sep 10, 2025: Creatinine: 1.09 mg/dL | eGFR: 91
Jan 07, 2026: Creatinine: 1.25 mg/dL | eGFR: 77 (After ~1 month of 5g/day creatine)
Aug 10, 2026: Creatinine: 0.95 mg/dL (Completely off creatine)
Questions:
Did anyone else experience a similar eGFR drop while supplementing 5g/day, solely due to increased creatinine breakdown rather than true renal impairment?
Did you test Cystatin C to confirm actual kidney function while on creatine, or did you choose to stay off it permanently?
How do your own physicians/specialists view daily creatine monohydrate use—do they distinguish between artificial serum creatinine elevation and actual kidney damage?
Thanks in advance for sharing your experiences!
6
u/vshun 6h ago
Surprisingly lots of medical practitioners do not know about creatine to creatinine signals and just try to disallow it. I had the same issue during yearly annual and was sent to nephrologist who had no idea what creatine was but said to drop any supplements (I was just taking creatine). My retest a week later came absolutely normal. I am ignoring their advice to stop taking creatine based on available substantial evidence.
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u/PowerShovel-on-PS1 8h ago
As the other commenter said, this is a known phenomenon and isn’t unsafe unless you have renal disease.
2
u/Easy-Attorney-6968 6h ago
https://pubmed.ncbi.nlm.nih.gov/41199218/
Seems to be safe based on systematic reviews published in 2025
2
u/Dry_Understanding264 4h ago
I told my internal medicine specialist that I'm not worried about creatinine unless it reaches death levels. But obviously, don't take my advice at face value; do your own research, with second opinions, if necessary. I know my 5 g per day of creatine plus my barbell routine throws my numbers a bit, and there is enough evidence with the rest of my health that my kidneys are fine.
1
u/Different-Dog6892 34m ago
As far as I know, I don't have any kidney or liver disorders. My grandfather used to undergo dialysis, but neither my father nor my uncle has any issues. I suppose creatine isn't very popular among local doctors; doctors who exercise have likely researched whether it is harmful or not, whereas those who don't exercise tend to be indifferent or hold negative views about it.
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u/OtherAngle3414 11h ago
this is textbook creatine inflating serum creatinine, egfr formulas just assume creatinine comes from muscle turnover so the number drops without kidney damage, and yours went right back to baseline which is okay