1. Start by selling online, and using an affiliate program to get the word out.
Sharasale.com is cheap to start.
If you dont know anything about affiliate marketing, just google it or hit me up and I'll send some stuff your way
2. Know your target maket, where are they and what do they want. Can you do aggressive type marketing, risk free trial, continuity programs
3. Gotta get the FDA, CIA,FBI, and Oprah's OK...But seriously make sure your legal stuff is in tack and you have at least a $1mm liability policy to start. You just need one person to say I had to got the hospital because of your stuff and then your done.
4. The easiest way is to JV with a supplement company you can trust and get a NON compete and NDA in place BEFORE any real talks or trade secrets are let out of the bag.
I'm sure Im forgetting alot. But it's a start