Also known as:four part test · 4-part test · four parts test · four-factor test
Written by attorneys · grounded in primary & secondary sources — see below
An analytical framework used to evaluate restrictions on commercial speech under the First Amendment. The speech must first concern lawful activity and not be misleading. If that threshold is met, a regulation is valid only when the asserted governmental interest is substantial, the regulation directly advances that interest, and the restriction is no more extensive than necessary.
Sources & Authorities
How it applies
Common Examples
2
Streaming Platform Drug Ads
The State Health Authority bars pharmaceutical companies from advertising prescription drugs directly to consumers on streaming platforms and permits only print ads in medical journals. PharmaCorp challenges the rule as an unconstitutional limit on truthful commercial speech. A court applies the four-part test and examines whether public health is a substantial interest, whether the streaming ban directly advances that interest, and whether less restrictive alternatives such as disclosure rules would suffice.
Solar Installer Savings Claims
The State Energy Commission forbids local solar installers from advertising projected monthly bill savings based on verified data while allowing utilities to advertise estimated bills. SunPeak Solar sues, claiming the selective ban violates its First Amendment rights. A court applies the four-part test, finds the speech truthful and lawful, and concludes the rule fails because it restricts one competitor more extensively than necessary to protect consumers.
Put it into practice
Test Yourself
8
Practice Questions3
· 1 primary source
Select any source to read its text and confirm it supports the definition.
Cases
Hornbooks
Study Supplements
Common questions
Frequently Asked
4
What is the first step of the four-part test for commercial speech restrictions?+
The speech must concern lawful activity and not be misleading. If that threshold is not met, the government may prohibit the speech outright.
Supporting sources
When does a commercial speech regulation fail the fourth part of the test?+
The regulation fails when it is more extensive than necessary, meaning there is no reasonable fit between the means chosen and the asserted governmental interest.
Supporting sources
Does rational basis review apply to restrictions on truthful commercial speech?+
No. Truthful commercial speech about lawful activity receives intermediate scrutiny under the four-part test rather than mere rational basis review.
Supporting sources
Can a state ban all advertising in a category simply because some ads might be misleading?+
No. The government must still satisfy the remaining parts of the four-part test and may not suppress all speech in the category without further analysis.
Supporting sources
Constitutional LawIndividual rights · First Amendment freedomsUBEIntermediate