Why does creatine make muscles look fuller?

Original Title

Creatine supplementation increases glycogen storage but not GLUT-4 expression in human skeletal muscle.

Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms

Summary

Taking creatine for a week makes muscles store more sugar (glycogen), which pulls in water and makes muscles look bigger. But after a week, taking less creatine stops this effect.

Sign up to see full results

Get access to research results, context, and detailed analysis.

Surprising Findings

Creatine increased muscle glycogen by 18±5% without changing GLUT-4, GS-1, or Gln-1 expression.

It’s widely believed creatine works by upregulating GLUT-4 to pull more glucose into muscles. This study shows that mechanism is wrong—yet glycogen still rose, meaning a completely unknown pathway is involved.

Practical Takeaways

If you want the 'fuller muscle' look, do a 5-day creatine loading phase (20g/day). But if you switch to maintenance (2g/day), the effect fades.

low confidence

Unlock Full Study Analysis

Sign up free to access quality scores, evidence strength analysis, and detailed methodology breakdowns.