Assistant Professor of Health and Kinesiology, University of Illinois Urbana-Champaign

A dangerous social media trend that started in 2020 has persisted into 2026, with heartbreaking consequences.

One study has estimated that this challenge may have been responsible for as many as 131 deaths in the U.S. between 2020 and 2024.

As with all online trends, the Benadryl Challenge is not limited by geographical borders. Though it originated in the U.S., public health officials in Canada have been warning parents and clinicians about the same trend since it began.

I research the powerful effects of social media on health behaviours such as substance use, sexual health and nutrition. The speed at which online trends like the Benadryl Challenge spread presents a new challenge for public health.

The science behind diphenhydramine overdose

Diphenhydramine is marketed under various brand names and is available over the counter as a treatment for allergies in numerous countries. The drug works by blocking a neurotransmitter called acetylcholine, which can help calm the body’s response to allergens.

Although therapeutic doses are generally safe, taking too much can result in severe anticholinergic toxicity. Symptoms of this condition include delirium, seizures, an abnormal heart rhythm, hyperthermia, coma and death.

Many young people may underestimate the drug’s potential risks because it’s inexpensive and available at nearly any pharmacy or retail store. Plus, teens are highly susceptible to peer pressure and fear of missing out, so they may not appropriately weigh the risks with social media users and influencers encouraging experimentation with this drug.

‘Over-the-counter’ doesn’t mean ‘safe’

The Benadryl Challenge highlights a broader public health challenge: the perception that medications available without a prescription are harmless. Even adults tend to consider diphenhydramine to be a “safe” household medicine.

But poison control centres and emergency departments have been responding to an increasing number of reports about intentional misuse of this and other over-the-counter medications among young people since 2020, with social media contributing to the rapid spread of dangerous behaviours.

In response, public health agencies have increasingly recognised that preventing medication-related harms requires both educating consumers and engaging with the digital environments where risky behaviours emerge.

In 2020, when videos of this trend first emerged on TikTok, the U.S. Food and Drug Administration issued a warning about the Benadryl Challenge, emphasising the risks of high-dose diphenhydramine use among adolescents. The agency urged parents, caregivers and healthcare professionals to discuss medication safety with young people.

The FDA also contacted TikTok and encouraged the platform to remove videos promoting the challenge and to remain vigilant against similar content.

More broadly, governments have begun holding social media companies accountable for failing to protect children from harmful online content. For example, the European Union’s Digital Services Act and the United Kingdom’s Online Safety Act establish regulatory frameworks for penalising platforms that fail to address risks to minors.

Global response to the Benadryl Challenge

Still, responses to the Benadryl Challenge outside the U.S. have largely consisted of public awareness efforts rather than formal regulatory action specifically targeting this trend.

The name “Benadryl” can also create confusion internationally. In the U.S., Benadryl allergy products contain diphenhydramine, the medication involved in the challenge. But products sold under the same brand name abroad contain different active ingredients.

In Canada, public health messaging has focused on raising awareness among adolescents and their caregivers after 2026 reports that the challenge resurfaced among youth. In May, a First Nation community in Ontario issued an alert warning families about the dangers of intentionally consuming high doses of diphenhydramine, following reports of youth participation in the trend.

Preventing the next viral health threat

The evolving response to the Benadryl Challenge aligns with the World Health Organization’s call for proactive public health communication. Rather than responding to harmful online trends after they’ve gone viral, public health efforts are increasingly focused on early education, timely risk communication and rapid dissemination of accurate information.

This includes improving medication safety education, strengthening digital health literacy and helping young people critically evaluate health-related content they encounter online. School-based medication safety programs, such as Generation Rx, may help reduce susceptibility to future medication-related social media challenges.

Caregivers, schools, healthcare providers, poison control centres, public health agencies and technology companies all have a role in identifying emerging risks and communicating accurate information quickly.

Helping young people recognise dangerous online content and understand the consequences of participating in these trends may be one of the most practical ways to reduce harm before the next viral challenge emerges.