I've heard that a lot of the girls in Latin America use an Estrogen called Gravidinona which is injected.

Anyone have experience with it?

No but I just checked it and it contains a progestogen as well. Seems like a high dose of P relative to the E.

I'm wondering if having the added Progesterone gives it more kick and is why some girls swear by it.

Wondering the same...

I also don't know if its coincidence but the girls I've seen that use it seem to be way more curvy. 

I've noticed the same with me I think, since adding progesterone, my butt is more prominent Was the same pre-op with cyproterone acetate, a progestogen.