Health warning messages could encourage teenagers and young adults to reduce their social media use, according to a new Stanford Medicine-led study. The research suggests that simple pop-up warnings about mental health risks may increase awareness and make users less inclined to keep scrolling.

The study involved 1,012 participants, about half of whom were teenagers aged 13–17, while the rest were young adults between 18 and 29. The findings were published online on September 4 in JAMA Health Forum.

Researchers tested 14 different social media warnings alongside a control message unrelated to social media. Participants viewed the messages in a format designed to resemble Instagram and rated how strongly each warning discouraged them from using social platforms and how much it increased their awareness of potential harms.

Mental Health Messages Worked Best

The warnings covered several topics, including addiction, body image, sleep disruption, depression, anxiety, broader mental health effects and the fact that social media has not been proven safe for young people.

Messages focusing on overall mental health harms, depression and anxiety received the strongest responses. Participants generally rated all social media warnings as more effective than the unrelated control message.

The study also compared health warnings with a message suggesting that users take a break from their screens, similar to prompts already used on some platforms. With the exception of the addiction warning, health-focused messages were rated as more effective than the simple break reminder.

Lead author Anna Grummon, PhD, assistant professor of pediatrics at Stanford Medicine, said the results suggest that wording matters significantly. In her view, researchers need to identify which formulations are most likely to influence behaviour rather than assuming that any warning will have the same effect.

Similar Results Across Age Groups

One unexpected finding was how similarly teenagers and young adults responded. Researchers had anticipated that age might influence reactions because digital habits and online environments can change quickly between adolescence and early adulthood. Instead, both groups consistently indicated that the warning messages could make them less likely to use social media.

Senior author Thomas Robinson, MD, the Irving Schulman, MD, Professor in Child Health, said participants across both age groups responded in a broadly similar way and believed the messages could reduce their social media use.

The researchers also tested California’s planned warning language. The state has passed legislation requiring such warnings from January 1, 2027. Its longer message performed about as well as several shorter health warnings.

Why the Study Matters

The research follows a 2024 call from then-U.S. Surgeon General Vivek Murthy for social media to carry health warnings similar to those used for products associated with health risks.

Since then, California, Colorado, Minnesota and New York have passed laws requiring social media warnings, while proposals have also been introduced in several other states.

Previous studies have linked heavy social media use with depression, anxiety, poor body image and sleep problems. However, this new experiment did not directly measure whether people actually spent less time on social media after seeing a warning.

That limitation is important. The study measured perceived effectiveness rather than real behavioural change.

What Comes Next

The Stanford team now plans to investigate whether these warning messages can produce measurable reductions in social media use over time.

Grummon explained that effective health warnings can influence behaviour, but social media presents a particular challenge because the messages may appear only briefly as pop-ups rather than remaining continuously visible.

Future research will therefore need to examine not only the wording of these warnings, but also how frequently they appear, where they are placed on a platform and whether their effect remains strong after users see them repeatedly.

The results suggest that health warnings may become one useful tool for promoting healthier digital habits, but stronger evidence is still needed before their long-term impact can be determined.