Injection site rotation on tirze — abdomen vs thigh, does it matter?

Both work. Abdomen tends to have slightly faster absorption due to higher vascularity, thigh is slower and more gradual. For weekly dosing this is clinically irrelevant — total AUC is basically the same. Use whichever is more comfortable.

Rotate both. I do abdomen three weeks, thigh one week, cycle. Keeps any single area from getting lumpy / bruised. Also you'll want the flexibility if you ever develop an injection reaction in one area.

Back of arm works too if you have someone to help. Not a daily option but a 'travel and don't want to expose abdomen' option.