I saw a dietician and had blood taken and tested, from memory. I was encouraged to do it by family who were bothered by my weight and so on. It was a few years back at this point, so I don't entirely remember the details.
I'm not sure how exactly you would test it at home, and it doesn't sound like it'd be particularly safe or effective. But I have no clue.
I'm not sure how exactly you would test it at home, and it doesn't sound like it'd be particularly safe or effective. But I have no clue.