California Gov. Gavin Newsom signed legislation on Monday that will require platforms to regularly display warning labels of the addictive nature of social media.

The bill, AB 56, is among several measures the governor signed to establish greater guardrails on social media and AI.

AB 56, from Assemblywoman Rebecca Bauer-Kahan, will require that platforms display a black box “to certain users each day the user initially accesses the social media platform, again after 3 hours of cumulative active use, and thereafter at least once per hour of cumulative active use, as prescribed.” It will not be required if that platform “has reasonably determined” that the user is over the age of 17.

The warning labels will read, “The Surgeon General has warned that while social media may have benefits for some young users, social media is associated with significant mental health harms and has not been proven safe for young users.”

The law will take effect on January 1, 2027.

The black box warning must be displayed for 10 seconds, unless the user clicks an X icon, and cover at least 25% of the screen of the site. After three hours of use, the warning must be displayed for at least 30 seconds, without the ability to click through, and it must cover 75% of the screen.

Opposing the bill was TechNet, the trade association that includes such tech giants as Meta and Google. They have raised constitutional concerns as it would be a “government mandated label on user generated speech,” per a bill analysis. The legislation does not include a private right of action.

Newsom also signed legislation to require app stores and other online services to establish age verification. Streaming services and video game developers have expressed concerns over the law, Newsom noted in a signing statement, and urged the state legislature to address those before it goes into effect on January 1.

Newsom also signed legislation to require that AI chatbot companions disclose interactions that are AI generated, and to require that platforms establish protocols to address users who express thoughts of suicide or self harm.

Other laws the governor signed increase the penalties for “deepfake” pornography.