How much time it takes to have flat nipples after gynecomastia surgery? 1 month post-op.

First off, congratulations on your gynecomastia surgery!
Puffy nipples are likely due to swelling after surgery. It will subside in about six weeks, so you just have to be patient for two more weeks and continue the post-operative care your surgeon prescribed you.
Don’t forget to go on follow-up consults with your experienced and board-certified plastic surgeon.
Best of luck!

Swelling is probably what is causing your post op puffy nipples. Generally, this will subside in 6 weeks although it can take anywhere from 3-6 months for all of the swelling to resolve and for you to have your final results. Although it's frustrating, be patient. Best of luck.

It completely depends on type of surgery you had. If you had the appropriate amount of gland removed from behind your nipples, they should be flattening out at this point. You will need to wait another several weeks and follow up with your surgeon to be sure.