No, C4 is not banned. However, some versions of C4 pre-workout were reformulated to remove ingredients like synephrine and dendrobium, which have been scrutinized in certain countries and sports organizations. The current formulations of C4 are legal and widely available.

C4 can be considered good for you when used correctly and in moderation, as it provides a boost in energy and focus for workouts, which can help improve exercise performance. However, it contains high levels of stimulants like caffeine, so it may cause side effects such as jitteriness, increased heart rate, or insomnia in sensitive individuals. Long-term use or excessive consumption can lead to negative effects, so it's important to follow the recommended dosage and consult with a healthcare professional if you have any underlying health concerns.