Having heavy breasts, by the end of the day my posture becomes worse, and often my back will feel a bit sore as well. I wear a 40DD in most brands, but when I ordered this bra in my size, it didn't fit at all; for one, the band was too tight. Secondly, the cups were too large! It also puckered badly along the seams running through the center of the cups, making it impossible to wear under a t-shirt without being noticeable.

I noticed no assistance at all all with my posture...I could slouch with my shoulders thrust forward and didn't feel the slightest bit of resistance. There are bands crisscrossing one another across the back of the bra, which I assumed were what would offer posture support & resistance, but there was no discernible difference between the stretchiness and resistance of these bands and a typical cotton sports bra.

The material is actually comfortable, but the bra just didn't do what it claimed to do regarding posture. If you still want to try, I would recommend going one or two band sizes up, and one cup size down.