Order DHT (dihydrotestosterone) blood testing online
In the majority of US states you can order DHT testing online and have the blood drawn at a local blood draw center (see my general overview of the process).
I'd suggest ordering from Life Extension because they have the cheapest price I know of ($50), and I've been happy with their service. You can also compare the other 6 DHT test providers I've found.
Take a look at my state-specific issues page if you're in AZ, MD, NJ, NY or RI.
If you're interested in self-testing as I am, check out my Facebook or Twitter account where I post interesting self-testing news and get a little too excited about blood test sales.