Scyllo‐ or myo‐. Physicochemical studies with potentiometric and NMR titrations show that, at physiological PH, the microprotonation patterns of synthetic scyllo‐inositol pentakisphosphate (scyllo‐InsP5) resemble those of its close relative, the intracellular signalling molecule myo‐Ins(1,3,4,5,6)P5, as shown by their conditional probabilities (%) at pH 7.5. This makes scyllo‐InsP5 a promising tool for identifying those biological effects of myo‐InsP5 that are mediated by specific binding proteins (centre), rather than by nonspecific electrostatic effects.