Since 1980, the courts have analyzed regulations affecting advertising for commercial products or professional services (i.e., commercial speech) under the four-part test set forth by the U.S. Supreme Court in Central Hudson Gas & Electric Corp. v. Public Service Commission of New York. The "Central Hudson" test asks:
- (1) whether the speech at issue concerns lawful activity and is not misleading;
- (2) whether the asserted government interest is substantial; and, if so,
- (3) whether the regulation directly advances the governmental interest asserted; and
- (4) whether it is not more extensive than is necessary to serve that interest.
In this analysis, the government bears the burden of identifying a substantial interest and justifying the challenged restriction: “The government is not required to employ the least restrictive means conceivable, but it must demonstrate narrow tailoring of the challenged regulation to the asserted interest — a fit that is not necessarily perfect but reasonable; that represents not necessarily the single best disposition but one whose scope is in proportion to the interest served.”
Moreover, “the four parts of the Central Hudson test are not entirely discrete. All are important and, to a certain extent, interrelated: Each raises a relevant question that may not be dispositive to the First Amendment inquiry, but the answer to which may inform a judgment concerning the other three.”