The Study
Effects of six weeks of high-dose creatine monohydrate supplementation with or without guanidinoacetic acid on homocysteine and markers of health
This study gave different supplements to people and checked their blood before and after to see what changed. It can tell us that the supplements probably caused small changes in certain blood numbers, but it didn't check if people felt smarter or had better energy — so we can't say it helps your brain.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave healthy people extra creatine (and a related chemical) for six weeks to see if it changed their blood health markers.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 576 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The changes are too small to matter for health—like a tiny dip in blood sugar that doesn’t improve diabetes risk, and higher creatinine that just means more creatine is being made, not that kidneys are damaged.
- 2Creatine lowered blood sugar (HbA1c) by 0.2%, lowered homocysteine by 1.3 points, raised creatinine by 0.08, and made eGFR drop by 7.5—but all numbers stayed in the normal range.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the International Society of Sports Nutrition
Year
2025
Authors
Khatereh Babakhani, Jisun Chun, Drew E. Gonzalez, B. Dickerson, R. Sowinski, Christopher J. Rasmussen, R. Kreider
Related Content
Claims (6)
Taking creatine supplements is associated with improved brain health.
Taking 10 grams of creatine monohydrate daily for six weeks lowers homocysteine levels by about 1.3 micromoles per liter in healthy adults. This reduction does not occur when creatine is taken with guanidinoacetic acid.
Taking 10 grams of creatine monohydrate and 2 grams of guanidinoacetic acid daily for six weeks lowers the estimated glomerular filtration rate by 7.5 mL/min/1.73m² due to higher creatinine levels, not because the kidneys are damaged.
Taking 10 grams of creatine monohydrate daily for six weeks lowers HbA1c levels by 0.2 percentage points in healthy adults.
Taking 10 grams of creatine monohydrate daily for six weeks raises serum creatinine levels by about 0.08 mg/dL in healthy adults. This increase is statistically significant but stays within the normal range seen in healthy individuals and does not signal kidney damage.
Taking 10 grams of creatine monohydrate and 2 grams of guanidinoacetic acid daily for six weeks does not change liver enzyme levels, electrolyte balance, blood fat levels, or blood cell counts in healthy adults.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.