Menstrual cycle trait preferences do not occur throughout the cycle. Females have been found to experience different eating habits at different stages of their menstrual cycle, with food intake being higher during the luteal phase than the follicular phase. Food intake increases by approximately 10% during the luteal phase compared to the follicular phase. Various studies have shown that during the luteal phase woman consume more carbohydrates, proteins and fats and that 24-hour energy expenditure shows increases between 2.5-11.5%. The increasing intake during the luteal phase may be related to higher preferences for sweet and fatty foods, which occurs naturally and is
Pharmacokinetics of progesterone and has been found to result in higher serum peak progesterone levels relative to intramuscular oil formulations. In addition, subcutaneous injection of progesterone is considered to be easier, safer (less risk of injection site reactions), and less painful relative to intramuscular injection. The elimination half-life of this formulation is 13 to 18 hours, compared to 20 to 28 hours for intramuscular injection in oil. Progesterone has a very short elimination half-life of about 3 to 90 minutes when given by intravenous injection. A one-year progesterone intrauterine device (IUD) for hormonal birth control was previously available in the United States and