You should become aware of the FDA regulations on health claims for nutraceuticals.
There are a few important factors you should research: manufacturing, distribution and marketing.
It is relatively easy to find a manufacturer for a private label product (putting your label on an existing formula). It will take a bit more work and expense if you are creating a new formula; ie., finding a scientist and lab.
Don`t let Marketing a nutraceutical according to FDA regulations scare you. According to the 1994 Dietary Supplement Health and Education Act. Dietary supplements can make "structure/function" claims, such as "Vitamin A promotes good vision" or "St. Johns Wort maintains emotional well-being," so long as the label bears a disclaimer that the claim has not been evaluated by the FDA and that the product is not intended to diagnose, treat, cure or prevent disease. Until recently, dietary supplements could not make overt health claims (e.g., "Vitamin A prevents, cures or treats poor vision" or that "St. Johns Wort cures or treats depression") unless the FDA specifically permitted such a claim (as it has in the case of folic acid and the prevention of neural tube defects in babies). This is actually changing...
There are signs the FDA is loosening up these regulations on a case by case basis so be sure to consult an attorney.