I'm asking this question on behalf of a friend. She's on exchange in Germany, and she hasn't had a period since August when she got there. She went to see a doctor in Germany to make sure everything was okay. She and the doctor concluded that she wasn't getting a period because she was stressed about being in a new country and had lost a lot of weight (she went from 60 kg to 49kg --130 to 108lb-- between July and now, just from eating healthier and exercising more). She's not underweight or anything, but the doctor says that her weight loss is probably stressing her body.
The doctor prescribed her something to regulate her hormones. The doctor told her it was "natural", whatever that means. And she says that if the natural thing doesn't get her period back in 3 months, she should start hormonal birth control. According to the doctor, her lack of period means she's lacking in estrogen (?? My friend didn't for sure remember if that was the hormone affected) which can cause osteoporosis (she also didn't remember if that was the name, something to do with the bones).
Basically, she and I both feel that not having a period for a few months (it's been 2 or 3) is not cause for worry and won't cause long term damage. Are we wrong? Should she take the thing her doctor recommended?
This is making me wish I knew more about hormones!