Caffeine and Creatine

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

Caffeine

The most-used and best-evidenced cognitive and physical stimulant on earth — precise dosing and a hard afternoon cutoff are the whole skill.

Grade A4 graded outcomesrevised Jul 10, 2026

A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.

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.

Swap the two

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 Caffeine

  • Alertness / reaction time Moderate effectEvidence grade A
  • Endurance performance Moderate effectEvidence grade A
  • Strength / power Small effectEvidence grade B
  • Sleep (afternoon dosing) Moderate effectEvidence grade A

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

Conditions

Only in Caffeine

None.

Only in Creatine

What each entry says about the other

Neither entry records anything about the other. That is not evidence that they do not interact — only that neither entry says.

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.