Celsius energy drink is not inherently bad for most people if consumed in moderation, but it does carry some health considerations mainly due to its high caffeine content (around 200 mg per can). It is not recommended for children, people sensitive to caffeine, or anyone who consumes more than two servings daily, as excess caffeine can lead to insomnia, increased heart rate, anxiety, and other side effects. Celsius has some evidence suggesting it may boost metabolism and improve exercise performance slightly, but these effects are small and the claims of it being a "healthy" drink are often seen as marketing rather than fact. Also, Celsius is not FDA approved due to certain ingredients like guarana, and it has been subject to lawsuits related to ingredient labeling. Overall, it is best treated like other energy drinks—use with caution and moderation, and do not rely on it for health or weight loss benefits.