I thought I had great cholesterol, but a trendy new blood test said the opposite — sending me down a mind-boggling rabbit hole

I tried Function Health, a trendy new $500 membership service that tests your blood and urine for a whole spectrum of issues.

Hilary Brueck, Function Health

• A new $500 membership service allows patients to skip the doctor's office and get their own labs.
• Function Health then gives people nutrition and supplement advice, and encourages retesting.
• I found the extra data interesting, but ultimately needed a doctor to properly interpret it.

The Rock loves it, Zac Efron invests in it...