Lower-caffeine soft drinks, such Diet Coke, are not affected by the ban, and neither are tea and coffee.
TV chef Jamie Oliver has repeatedly warned of the dangers and disruption energy drinks can cause, with kids coming into school "bouncing off the walls" having had energy drinks for breakfast.
"We are talking about three, four shots of espresso in one of these things. Loads of sugar. So an absolute nightmare," he said in a video posted on X last year.
Under current labelling rules, any drink, other than tea or coffee, with over 150mg of caffeine per litre requires a warning label saying: "High caffeine content. Not recommended for children or pregnant or breast-feeding women."
Young people have smaller bodies and their brains are still developing, which can make them more sensitive to caffeine, say experts.
For most adults, up to 400mg of caffeine a day, or about four cups of instant coffee or five cups of tea, is safe.