By US law, a disclaimer is required on products that have not been tested by the FDA:
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=101.93Specifically, the following text is required by statute:
(c) Text for disclaimer.
(1) Where there is one statement, the disclaimer shall be placed in accordance with paragraph (d) of this section and shall state:
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
I wish that there were a further requirement on television advertisements such that that disclaimer must be in the same size (or larger) letters as the contact information (telephone number, website, etc.).
For print advertisement, there is a specification for minimum text height (1/16").