It is not necessarily dangerous to take a pre-workout every day as long as you follow the manufacturer's instructions and do not have any underlying health conditions. It is recommended to start with the smallest possible dose and be mindful of the caffeine and other stimulants in pre-workouts to adjust your overall caffeine intake accordingly. It is worth noting that some studies have shown no significant difference in performance or muscle gain between individuals taking pre-workouts and those who do not. Adequate hydration, proper nutrition, and sufficient rest are typically more important factors for optimal performance.