Multilamellar structures formed in DPPC/water/glycerol and DPPC/water/oxyethylated glycerol systems are studied by small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) methods. The effects of glycerol, oxyethylated glycerol, and other membranotropic agents (MTAs) on the lamellar repeat distance 𝐷 are compared in gel, ripple, and high-temperature (𝐿𝛼) liquid crystal phases of the hydrated phospholipids. It is noted that the introduction of MTAs could lead to different types of '𝐷 vs. temperature' behavior in the 𝐿𝛼 phase, which is correlated with changes in 𝐷 caused by the introduction of these substances to the DPPC/water reference system. K e y w o r d s: small-angle X-ray scattering, membranotropic agents, liquid crystal, dipalmitoylphosphatidylcholine.