The bra put on me after my 12/22 lumpectomy and breast reconstruction was from Marena. That one is too tight now, but I bought others from Marena.com, and I am still wearing them, partly for help with the fibrosis that developed (see below), and for best support. As someone else said, compression bra should be snug, but definitely not uncomfortably tight.
Another source is lymphedemaproducts.com.
Bras at both these sources are pricey, but I think they are worth it as they are well made and exactly for the problem. I also like that they hook in the front.
I also have 2 ‘sports bras’ from Coobie, which have less support but still somewhat compressive. I have to step into them to put them on—I found that works better than trying over my head.
It is important to get the right size. Follow the instructions on Marena for that—the sizing may be different from your pre-cancer bra.
About 4 months after surgery I developed lymphedema and fibrosis where the lumpectomy took place. I went to OT for that for several weeks and the therapist told me it would not go away. I continue to do massaging for the fibrosis and also wear a small insert over that area which the compression bra helps with. The particles inside that piece move as I move and help continue ‘massaging’ the fibrotic area. Helps to keep it somewhat softer.
Hope this helps, and best of luck to you.