The self-imposed rules of a no-buy challenge are simple: participants pledge to stop buying non-essential items, be they unneeded shoes, additional beauty products or other impulse buys for a set amount of time, usually 12 months. What started several years ago as a blogged-about experiment in budgeting and mindful spending has become a popular trend on social media. A Reddit group where people share their experiences has 51,000 members. On TikTok, some users post videos to hold themselves accountable that get hundreds of thousands of views. Not everyone electing to join the no-buy trend has debt. Some participants say they want to do their part to reduce waste and protect the environment.