I had the Mirena inserted last October, when my youngest child was about 18 months old. IMMEDIATELY, as in 2 days later, I started to feel tired. The way I've described the feeling is to say "pregnancy tired"--there is, to me, no exhaustion compared to pregnancy exhaustion. And it was like someone flicked a switch, the change was so dramatic. I could have easily fallen asleep at any point in the day in about 2 seconds flat. Cloudy thinking, forgetful. I mentioned it to my doctor and she dismissed my concerns at first, since this is not a common side effect--she reminded me that I had 3 kids under the age of 5, and this is likely the cause of my exhaustion (dismissing the fact that this unique exhaustion began 2 days after the insertion), and that I was still breastfeeding and waking up in the middle of the night. She finally said to me, "Well, most side effects level off after six months. Hold out, it will get better!".
I had a thyroid test, no issue there.
I didn't have any major cramping, headaches, or anxiety. I felt "down", but I attributed this to my exhaustion, and how I just couldn't seem to get anything done. My husband is wonderful, very supportive and helps out a lot with chores around the house, and is my partner with child-rearing duties, but I still felt guilty and extremely frustrated for not being able to do all the things I wanted to do. Once the kids went to bed (and sometimes even before then!) I was a zombie and totally useless. Very little motivation. I already have three kids--as if I can afford to be MORE exhausted!
The upside for me has been, "Well, at least I'm not pregnant!". I did experience some hair loss, but that seemed to level off at around month 3 or 4. My sex drive diminished but then again, I was breastfeeding and just the exhaustion alone was enough to curb my interest.
Finally, after 8 months of exhaustion that did not seem to be getting any better, I decided to have the Mirena removed. That was TODAY. I figured that it would take a while for the hormones to leave my system, and now I'm reading about a potential "crash" and I'm petrified.
When I came home, I resolved to report my side effect somehow, somewhere, since my doctor really didn't seem all that interested. She just said, "Well, you must be sensitive to the hormones"...yeah that's an understatement! I did some research about side effects (of course as I've done over the previous months), and I've had a hard time finding anything about exhaustion, until I stumbled upon this board.
As an aside, I have to mention that my 2-year old, who is still nursing, is having growth issues and we are trying to figure out why. It's most likely completely unrelated, but just throwing it out there.