Have you? I've tried on a friend's Mass Effect cosplay armor. As for real stuff, I've worn combat vests and general bulletproof vests that go under casual clothing. The majority of the stuff I've tried is certainly not for the female anatomy, but some of it does and it works wonders. But you know what it doesn't do? Lift and separate my boobs. Because that's stupid. My issue here is that we don't need to lift and separate breasts but we can still compensate for them in armor, but without making concave breastplates. What's so difficult to understand about that?