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Updated: Feb 14, 2026

Author Spotlight: Deciphering the Mysteries of Skeletal Muscle Fiber Types Using the MyDoBID Technique
Published on: September 22, 2023
Human skeletal muscle contains no detectable guanidinoacetic acid
Sergej M Ostojic1,2, Jelena Ostojic3
1a Applied Bioenergetics Laboratory, Faculty of Sport and Physical Education, University of Novi Sad, Novi Sad 21000, Serbia.
Abstract:
We analyzed data from previously completed trials to determine the effects of supplemental guanidinoacetic acid (GAA) on markers of muscle bioenergetics in healthy men using 1.5 T magnetic resonance spectroscopy. No detectable GAA (<0.1 μmol/L) was found in the vastus medialis muscle at baseline nor at follow-up. This implies deficient GAA availability in the human skeletal muscle, suggesting absent or negligible potential for creatine synthesis from GAA inside this tissue, even after GAA loading.
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