I've been surgically modified such that my body doesn't produce sex hormones in any significant quantity on its own. As a substitute, I use separate transdermal gels containing testosterone and estrogen, which have relatively short metabolic half life in my body.

I normally target an estrogen level similar to an average woman and a testosterone level between the female and male reference ranges. I'm able to adjust the mix on the order of days when it suits me, and there absolutely is a difference. People who know me well can usually tell what mix I'm running.