Creatine and Protein intake
Each entry’s own grades, side by side. A grade says how strong the evidence is for one outcome — it does not rank one entry over the other.
Compound or practice
Creatine
The most-studied performance supplement in existence — and it quietly helps brains too.
Grade A5 graded outcomesrevised Jun 20, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Compound or practice
Protein intake
The macro with the strongest evidence in all of nutrition — most people building muscle need 1.6–2.2 g/kg, full stop.
Grade A4 graded outcomesrevised Jun 25, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Graded in both
Outcomes are matched by name. Two entries can describe the same outcome in different words, so one listed further down may still be graded in the other.
No outcome has the same name in both entries. They may still overlap under different wording — read the two lists below.
Graded only in Creatine
- Strength / power output Moderate effectEvidence grade A
- Lean mass (with training) Moderate effectEvidence grade A
- Working memory Small effectEvidence grade B
- Sprint performance Small effectEvidence grade B
- Bone density Unclear effectEvidence grade C
Graded only in Protein intake
- Lean mass (with resistance training) Moderate effectEvidence grade A
- Strength gains Small effectEvidence grade A
- Satiety / fat-loss adherence Moderate effectEvidence grade B
- Kidney harm (healthy adults) Trivial effectEvidence grade D
Conditions
- Sarcopenia (age-related muscle loss)Creatine: ImprovesEvidence grade BProtein intake: ImprovesEvidence grade A
Only in Creatine
- Depression May improveEvidence grade C
- Type 2 diabetes May improveEvidence grade C
- Chronic kidney disease No clear effectEvidence grade B
Only in Protein intake
- Obesity / weight management ImprovesEvidence grade B
- Osteoporosis May improveEvidence grade B
- Advanced kidney disease May worsenEvidence grade C
What each entry says about the other
- Creatine’s entry · Goes with: Additive lean-mass effects in the same training block
- Protein intake’s entry · Goes with: The two supplements with A-grade lean-mass evidence — additive, not redundant
Both columns are read from the entries as they stand in this library. A comparison is not advice to take either one, and it is no substitute for a clinician who knows the person.