When will my areola start shrinking after gynecomastia? 1 week post-op.

It will take about a month for your areola to start shrinking although it can take 6 months or longer for all of the swelling to resolve. Your chest will continue to change and improve daily so be patient. It is a process. Best of luck.

Depending on the size and appearance of your gynecomastia, you should see a real difference right off the table. They will continue to shrink and darken in color over time but the difference is usually immediate. The only concern I have with your comment is that it's possible that there is still tissue underneath the nipple-areola that hasn't been removed in which case it won't shrink much with time. 
Time will tell though!

Hello and thank you for your question.  The areola may start shrinking at about 4 weeks, as the swelling goes down.  It may continue to shrink and the final result may become apparent in about 9 to 12 months.