A process for evaluating rheological characteristics of an injectable gel including measuring the flexibility, wherein the flexibility is evaluated by measuring the strain at the crossover point of the amplitude sweep. The process may include subjecting an injectable gel to oscillating mechanical stresses to determine G′； and G″； as a function of strain (γ) in an amplitude sweep, determining the crossover point as the point at which G′； and G″； have the same value, determining the strain γcross at the crossover point, and determining the flexibility of the injectable gel as γcross or proportional to γcross. Further, a method of comparison of dermal fillers by measuring their flexibility and a method of evaluation of dermal filler behavior in human skin by measuring the flexibility.
