I just saw Black Widow. Yelena and Natasha say they don’t have any ovaries because the Red Room surgically removed them. That means no estrogen. But those women have definitely been through puberty. If you don’t have any estrogen or testosterone, your bones get weak like a child’s bones. That’s no good for being a super assassin. And I don’t think the Black Widow is on testosterone injections. She’s not hairy enough for it. So is she taking estradiol pills?
MCU Hulk was created when Banner was tasked with recreating the super soldier serum. I’ll give them credit for NOT running with “everyone gets super soldier serum”.
Until Falcon and Winter Soldier lol