I live in the US and have an endochronologist (excuse the spelling)..........I have been on 50 mcg for about 15 years............and this dose seemed to be on the medium side. Your dose seemed alot lower because of the decimal point you wrote (not sure if they even make synthroid at that super low level??)
I have a preference for brand drugs as opposed to generics .............My level has kept my blood testing within normal ranges. But, I do see that this can affect osteoporosis and yes, my bone density has been going down (I am 77) and I am wondering if this long time on synthroid would have made this difference. However "I" discovered the real problem.....
The main thing (for me at least) has been that the doctor totally missed a parathyroid tumor that was 1 inch wide. I was the one that decided to go to the Norman Clinic and speciality hospital. My doc didn't do a PTH test when he did the yearly thyroid testing......I don't know why except this blood sample has a very very short life and has to be tested by the lab almost immediately.....
Synthroid has been around for a long time and approved here in the US. Cost is relatively little as compared with the bone density drugs ............. who can afford that? If you have a bone problem, research well. Don't ignore the parathyroid. Yes, it has the same name (in a way) but the functions are different.......
I like PubMed for researching on line. Lots and lots of studies. For the lay person, the first paragraph (intent of the study) and the last paragraph (conclusion) is the most readable.
Good luck