In the rapidly evolving landscape of nicotine products, a new category has surged into the mainstream, gaining considerable traction on social media and becoming particularly popular with young men in the U.S.: oral nicotine pouches (ONPs). Leading this boom is Zyn, a brand of small, teabag-like sachets that have become a financial boon for an industry grappling with declining cigarette sales. Tucked discreetly between the lip and gum, these pouches deliver a potent hit of nicotine without smoke, vapor, or spit. Marketed by the tobacco industry as a cornerstone of its “harm reduction” strategy, Zyn and its competitors are promoted as a safer way for adult smokers to consume nicotine. But as their use skyrockets among a demographic far broader than just transitioning smokers, critical questions about their safety, addictiveness, and long-term health effects are coming to the forefront. This guide delves into what we know – and, just as importantly, what we don’t – about this rising form of nicotine consumption.