What you will feel, however, is the stimulation of your central nervous system, which is what gives you that boost of energy. A quick, convenient way to stay awake, all rolled up in one little pill. Pin On Life Style Other caffeinated products rely on wacky herbs and sugar to energize you. How long does caffeine pills take to work . Some caffeine pills on the market may offer doses that are too high to take for sensitive individuals. It synergizes well with caffeine and has anxiolytic/relaxant properties and reduces the jitteriness and physical discomfort that can come with caffeine consumption. Coffee, tea, pills or any other form of caffeine will all be absorbed / take effect at about the same rate. Vivarin has just one active ingredient, caffeine! Me, personally, it takes about 30 minutes from when the coffee hits my lips ’til i start feeling it. A toxic dose of caffeine is considered to be five or more grams. Pro plus caffeine tablets are a licensed medicine f...