Last year I had my gallbladder removed and my progesterone tanked. At first I thought it was because I had changed the fatty snack I took it with, but it tanked further after going back to the original snack. I realized the timing of the decline started right after my gallbladder was removed. I started taking digestive enzymes for fat and my progesterone is steadily rising again. Just wanted to share in case it helps someone else.