I remembered a HumanUpgrade episode with Christopher Shade. Here is the part you might be interested in
Christopher Shade:
[...]The thing that we're doing for men, but it's going to go through compounding pharmacies, is testosterone nanoparticle sublingual. This is a totally different approach to testosterone. Say your native testosterone is 300, you want to be riding higher. You take a dose of this, say, 12 milligrams. You'll go up to 2000 and over the next four hours come back to your baseline. That one shot on the androgens receptors is enough because the androgen receptors are stimulating all these downstream activity, which is really the androgenic activity. That one shot on the receptors is enough to carry you through. Maybe we'll end up doing it twice a day, but the beauty here is that when we're on, say, injectable, like when we're on testosterone cypionate, we're keeping this high level of testosterone all the time.
It goes up, it comes down, a little injecting and it goes up. What it does is it shuts off your testicular secretion, but it shuts off all your testicular function. It shuts down FSH and LH, and then what you get is testicular atrophy. They get smaller, ejaculate gets smaller, you're not making firm. Actually, injectable test is a contraceptive and it stops all these other things that your testicles do. We had tested this out a couple of years ago and people felt great on it, women really loved it, and so we're going to start doing this with college pharmacy. We have a bunch of people who we're starting the first testing with now, and by Q1 next year, we hope to have this thing out. Then once a day, you have this big peak of test and what we're hoping to see is the FSH and the LH stay up, testicular volume stays there, ejaculate volume stays there, quality stays there, yet you have that androgenicity that you're looking for.
Dave Asprey:
This may end up being a replacement for SARMs[...]