Selling dietary supplements on-line raises a host of legal issues, including rules relating to licensure and scope of practice; malpractice laws; legal rules and regulations by professional boards and organizations regarding conflict-of-interest (in medicine as in other health professions); rules about fraud; and rules governing Internet advertising and promotion.

On the latter front, those selling dietary supplements should review and follow the FTC’s Dietary Supplements: An Advertising Guide for Industry.
This guide clarifies that while “the FDA has primary responsibility for claims on product labeling, including packaging, inserts, and other promotional materials distributed at the point of sale,” the FTC “has primary responsibility for claims in advertising, including print and broadcast ads, infomercials, catalogs, and similar direct marketing materials.” The dietary supplements guide reiterates the principle that: “1) advertising must be truthful and not misleading; and 2) before disseminating an ad, advertisers must have adequate substantiation for all objective product claims.” The guide goes on to describe how to identify express and implied claims; make relevant disclosures; substantiate claims; and use endorsements, testimonials, and other forms and sources of claims. There is also an entire guide devoted to Use of Endorsements and Testimonials in Advertising, which includes endorsements by consumers, experts, and organizations.
Rules governing advertising on the Web more generally also are likely to apply.