A can of Red Bull contains the same amount of caffeine as a cup of coffee
A school in East Sussex has asked two local shops not to sell high-energy drinks to pupils.
Cardinal Newman School in Hove fears that the drinks could have an impact on children's behaviour in class.
Teachers at the school have also put up posters to remind pupils not to ask for the drinks.
Energy drink maker Red Bull has previously said it does not recommend its beverages to caffeine-sensitive individuals, including children.
Cardinal Newman said it took the action after becoming increasingly concerned about the number of pupils having high-energy drinks before and during the school day.
Head teacher Malvina Sanders said: "The school negotiated with our local Tesco Express store not to sell high-energy drinks to students from Cardinal Newman.
"This was a preventative measure, as all research shows that consuming high-energy drinks can have a detrimental impact on the ability of young people to concentrate in class.
"The school has placed a sign in Tesco Express, and another local convenience store, to remind students not to buy the drinks.
"As a result, staff are not put in the awkward position of having to refuse to serve them," Ms Sanders said.
Last year Bob Tait, of Drug Education UK, which delivers drug-awareness classes in schools, warned that the drinks could make pupils disruptive and hyperactive.
The makers of energy drinks have said that their products can boost concentration, contain about the same amount of caffeine as a cup of coffee and are not aimed at children.
Students give their views on high-energy drinks