Fig 1.

Mean serum concentration of DMPA in C57BL/6 mice after intramuscular administration. DMPA was administered to mice by means of two regimens. Group A received a weekly injection of 1 mg DMPA, whereas group B received a single injection with the same concentration of hormone. Serum of 5 mice in each group was collected at the following time points after initiation of DMPA treatment: day 1 and weeks 3, 8, and 16. DMPA serum concentrations were measured by high-performance liquid chromatography (HPLC) and tandem mass spectrometry (LC-MS/MS). Data are represented as means ± standard errors of the means (SEM).