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.
Several important peptide hormones are secreted from the pituitary gland. The anterior pituitary secretes three hormones: prolactin, which acts on the mammary gland; adrenocorticotropic hormone (ACTH), which acts on the adrenal cortex to regulate the secretion of glucocorticoids; and growth hormone, which acts on bone, muscle, and the liver.