2.3. Collection and Usage of Serum Samples
BLOOD
Blood samples were acquired from all fasting women through venous puncture on the day of completion of the questionnaires at the baseline and after treatment during daytime to allow the samples to stand for at least 30 minutes (indoor temperature). Then, the blood was treated by centrifugation to separate serum that was then kept at −20°C until use. The concentrations of melatonin, LH, FSH, and E2 level were analyzed by radioimmunoassay with kits manufactured by Immuno Biological Laboratories (Hamburg, Germany).