Berocca Boost effervescent tablets contain caffeine, there to give you a little kick exactly when you need it.^* As with every Berocca product, Berocca Boost contains B vitamins along with magnesium, zinc and vitamin C. However Boost also contains the herb guarana and, thanks to the caffeine in each effervescent tablet, Berocca Boost is ideal for helping to improve your alertness and concentration when you need it most.