Hello Lisagarmaise, Serotonin is to blame! Excessive release of 5HT(serotonin) from intestinal mucosa cells can cause diarrhea and nausea. Metformin stimulates these intestinal cells to produce increased levels of 5HT, as soon as 10-15 minutes after taking metformin. The good news is that most symptoms dissapear after taking metformin for 2-3 weeks.
Progesterone, hormone secreted by the female reproductive system that functions mainly to regulate the condition of the inner lining (endometrium) of the uterus. Progesterone is produced by the ovaries, placenta, and adrenal glands.
The pituitary gland is the most important part in the endocrine system. The pituitary gland secretes hormones on the basis of the emotional and seasonal changes. The hypothalamus sends information that is sensed by the brain to pituitary triggering production hormones.