Black Card imports raw materials from Brazil for 6 hours. The company originated in Guangzhou, China in 2005, and is also a functional beverage. The refreshing hormone is extracted from Guarana, a natural plant in Brazil. I went to the supermarket to compare it. The content indexes of caffeine-like, inositol and taurine are several times to dozens times lower than those of red bull, and they are mainly refreshed by natural extracts. The principle is different and has no physiological effect on teenagers. The bottle of its product is clearly marked: not suitable for people who are allergic to caffeine.