Estrogen isn’t a molecule. It’s a class of feminizing hormones, the most prominent of which is estradiol. Others include estrone and estriol. Collectively, these are called estrogens.
The masculinizing analog for estrogen is androgen (a word you practically never hear*), which also refers to a class of hormones. In addition to being the most well-known of the androgens, testosterone might be the most famous hormone in the whole body**. Dihydrotestosterone is actually the most potent androgen. Androsterone and Androstenedione are (relatively weak) others.
*e.g. It’s such an androgen fest!
**Adrenaline is the only competitor that comes to mind.
This moment of pedantry was brought to you by TankieTanuki. 
Holy shit, I’ve never noticed that. Admittedly I have only ever worn men’s shirts, but do the laundry all the time and I guess just never looked close enough at my wife’s shirts.
Now I’m going to need to look up why. Is there a reason aside from really weird misogyny?
Edit: preliminary research shows that it was possibly due to the intricate nature of women clothing in the renaissance era, usually a servant was doing the buttons