Creatine
muscle-building powders and pills. Longevity & fitness.
- Verdict
- UnclearThere isn't enough human evidence to say either way.
- How sure
- Rung 2 · LimitedFew, small or conflicting human studies, or only indirect measures such as blood markers.
The rung shows how sure the science is, not how big the effect is. How to read these ratings
Cancers affected
Testicular (one study)
What the evidence shows
There's little human research on creatine and cancer. In one case-control study (British Journal of Cancer 2015) of 356 men with testicular cancer and 513 without, men who'd used muscle-building supplements containing creatine or androstenedione had 65% higher odds of testicular cancer, higher still with use before 25, more than one product, or three years or more. The study can't separate creatine from the other ingredients, or show cause.
What to do
No evidence it prevents cancer. The testicular cancer finding is an association that needs confirming; mention long-term use to your doctor.
Sources
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Related
Every supplement we rated, or follow one cancer step by step: breast cancer, colorectal cancer, lung cancer and prostate cancer.