[aprilzero]

There's no way that I know of besides blood tests. It's a bit painful but not too expensive and in my opinion well worth it.

The blood levels are coming from a standard blood test, available at any doctor's office. I've been getting them about once a month.

You need to fast for at least 8 hours prior to get accurate results, and it takes about 2 vials of blood. I'm waiting for some sort of device to give you realtime values with just a prick of blood or constant monitoring.