How long after an arm lift is it safe to have blood pressure taken in the arm?

That's a great question.  Barring any wound healing or other post-operative complications, I allow upper arm blood pressure measurement four weeks after brachioplasty.  There are other areas, such as the leg or lower arm, that can be used until then.  I'm happy to hear that your are doing well.  I wish you the best.

Since you are 7 weeks out from surgery, this should be enough time to resume taking your blood pressure.  If there are any issues or concerns, you can always consult with your surgeon.