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.
 Some names of hormones that are secreted are estrogen,  testosterone, thyroid hormone, growth hormone and luteinizing  hormone.astrin stimulates the secretion of hydrochloric acid and pepsin; induces contraction of the lower oeso â¦ phagus; mildly increases the motility of the GI tract; and relaxes the pyloric sphincter. 1 person found this useful.