Hi @elaussies i also experienced noticable fatigue and tiredness during my first couple months of Forteo therapy. It was most likely due to the fact that Forteo impacted my blood pressure - reducing it from 90s/60s to low80s/low50s. My endo advised me to increase hydration (from 8 cups to 10 cups, or 2000cc to 2400cc) and add some salt to the water if needed. I did monitor my blood pressure throughout the day. It appeared my blood pressure was low all day long 24/7 so was my fatigue. Admittedly i couldnt do much at all during first one and half months. Luckily my body adjusted and I felt myself toward the end of 2nd month.

Please note that Forteo pen is not adjustable. The clicks that you hear is not calibrated with any corresponding dose. The full dose 20mcg is approved minimal effective dose.

If your symptoms remain intolerable after readjusting hydration level, it may be a good idea to communicate with your physician regarding this.