Chapter 12 contextualizes scientific claims about health benefits and considers evidence of adverse effects. The chapter argues that scientific support for school-based yoga, mindfulness, and meditation is weaker than often claimed and falls short of demonstrating that programs are secular, safe, or superior to alternatives. Low-quality studies report health benefits, using uncontrolled, pre-post designs, or nonactive controls, with small sample sizes, and high risk of bias, including expectation bias, researcher allegiance, publication bias, and citation bias; higher quality studies show less efficacy. Scientific evidence is not equivalent to evidence of secularity; research studies report that meditation in religious contexts, as well as prayer and Bible reading, can benefit health and activate specific brain regions. Some participants report challenging experiences with meditative practices, including anxiety, depression, physical pain, reexperiencing of traumatic memories, anger, and suicidality. Meditative practices may be contraindicated for participants with a history of trauma, PTSD, addiction, psychosis, anxiety, depression, or suicidality. Research shows that alternatives, such as aerobic exercise, math, music, nutritious food, or different behavioral therapies, can produce comparable benefits, including training the brain through neuroplasticity. Yet marketers rarely disclose risks of adverse effects, screen for contraindications, or provide information about alternatives.