Experimental and computational study of guanidinoacetic acid self-aggregation in aqueous solution

•Physicochemical and thermal properties of guanidinoacetic acid are determined.•GAA molecule is more thermally stable than creatine.•Experimental and computational study of GAA have been performed.•Existence of GAA self-aggregation is discussed.•At c(GAA) > 0.013 mol·dm−3 self-aggregation is observed.

In this work for the first time the physicochemical and thermal properties of guanidinoacetic acid (GAA) and its aqueous solutions have been performed to test for its viability as a potential dietary supplement. Thermal stability, viscosity, solubility and experimental density are determined. From measured densities the volumetric properties were estimated and discussed in the scope of GAA self-aggregation in aqueous solutions using experimental and computational results. Based on thermal stability and solubility measurements, it is found that GAA is more thermally stable but less soluble comparing to creatine due to a self-aggregation process that occurs at GAA concentrations higher than 0.013 mol · dm−3. Existence of self-aggregation influences the macroscopic properties of aqueous GAA solutions, but also its bioavailability.