The Laleaua Albă (White Tulip) magmatic complex (LA) consists of small-scale composite andesitic–dacitic dikes representing the third volcanic phase (8.5–8.0 Ma) of the Gutâi Volcanic Zone (GVZ) within the Neogene–Quaternary volcanic chain of the East Carpathians (Romania). The LA comprises two composite dikes that crosscut older volcanic units. The outcrop, at the sampling site exhibit a tulip-shaped light-colored dacitic core – containing abundant mafic microgranular enclaves (MME) – surrounded by a dark gray andesitic envelope. Volcanic rocks from the GVZ and LA display typical post-collisional (calc-alkaline) geochemical signatures. Based on their major element compositions, the studied clinopyroxenes are primitive (Mg#: 73–85) and represent the earliest crystallization phases. Clinopyroxene geothermobarometry indicates crystallization pressures of ~5.5–8.5 kbar, suggesting a deep magma storage system in the lower crust at depths of 22–30 km, proximal to the regional Moho (33–35 km). Micro-Fourier Transform Infrared (FTIR) spectrometry was used to determine the structurally bound hydroxyl contents of nominally anhydrous minerals (NAMs) across the three lithologies to reconstruct the volatile evolution of the dike system. Measured structurally bound hydroxyl concentrations in clinopyroxene (80–610 ppm), plagioclase (11–37 ppm), and quartz (2.5–9.5 ppm) indicate moderate to high values. The equilibrium water contents calculated from clinopyroxene range between 0.6 and 4.7 wt.% H₂O. These values are consistent with subduction-related calc-alkaline magmatism, though evidence of re-equilibration with the dacitic melt is observed, aligning with previous quartz-hosted melt inclusion studies. Variations in hydroxyl content between the dacitic host and MMEs record the history of magma mixing. The preservation of high hydroxyl concentrations indicates that the dike did not undergo significant post-emplacement degassing, maintaining high water activity during cooling. This study demonstrates that subvolcanic rocks can effectively preserve primary magmatic water signatures, serving as essential benchmarks for the volatile budgets of post-collisional volcanic systems.