How does that work in the vagina?
That's the most effective spot. The hormones are absorbed through the vaginal tissues similar to how nutrients inside the digestive tract are absorbed.
Granted, that's more or less like the end-goal - having sex, that is. However, hormones like testosterone (this being much better than the synthetic kind) will give her more vitality and better appetite, as well as increased libido.
There's also a fairly significant amount of Follicle Stimulating Hormone in men's semen. Follicle, here, doesn't refer to hairs, but instead the cells in the ovaries that surround ova, both protecting and nurturing their development. And regular intercourse will provide a steady external supply of this hormone. In essence, if a woman is having intercourse regularly, this will cause her to ovulate more regularly, and increase her odds of conception.
This also means that her periods are a lot more regular and predictable. And regular and predictable periods are much easier for a woman to cope with than irregular periods. Trust me, I've compiled an entire LIST of horrible things women have to put up with during their periods. It's like their body is taking revenge out on them for
not making a baby.
(This is also kind of a scary thing if you're trying to avoid that, because the so-called "Safe Period" is very, very small - about a week at most. The reason for this is because once a woman ovulates, that's far from being the end of the game. An ova will spend about two weeks making the trip from her ovaries to her uterus. At any point during this time, fertilization and conception is possible. And the fallopian tubes, unlike the rest of her reproductive tract, are a safe haven for spermatozoa. Spermatozoa can survive for
several days there. Which means that even if your partner hasn't ovulated yet, your little swimmers can lay in wait for when she does. Like I said: scary, huh?)
What it all boils down to is the simple fact that evolution and natural selection has made it so we're not just wired to want sex. It has ensured that so long as you're having regular sexual intercourse - male or female - you achieve peak performance, because peak performance = better ability to have and raise children.
Although in this setting, it's kind of a moot point, since apparently other species are not genetically compatible with each other. Which is kind of a shame, really. With their level of dedication, I think Roxane and Sherry would both be wonderful mothers. I think Michio would do okay, too, as a dad. Once he got over the panic, that is.